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SUMMARY: Adrenocortical carcinoma (ACC) is a malignant disorder with rapid evolution and severe prognosis in adults and most produce cortisol and androgen. Estrogen-secreting adrenocortical carcinomas are extremely rare, especially in women, tend to be larger and have worse prognosis compared with other types of ACCs. We report the case of a 58-year-old woman who presented with bilateral breast enlargement and postmenopausal genital bleeding. She presented high estradiol (818 pg/mL - 25 times above upper normal limit for postmenopausal women) and testosterone (158 ng/dL - 2 times above upper normal limit) levels and no suppression of cortisol after overnight 1 mg dexamethasone test (12.5 µg/dL; normal reference value: < 1.8 µg/dL). The patient had no clinical features of cortisol excess. MRI showed a 12 cm tumor in the right adrenal. Clinical findings of bilateral breast enlargement and postmenopausal genital bleeding with no signs of hypercortisolism associated with hormonal findings of elevated estradiol and testosterone levels would indicate either an ovarian etiology or an adrenal etiology; however, in the context of plasma cortisol levels non-suppressive after dexamethasone test and the confirmation of an adrenal tumor by MRI, the diagnosis of an adrenal tumor with mixed hormonal secretion was made. The patient underwent an open right adrenalectomy and pathological examination revealed an ACC with a Weiss' score of 6. Estradiol and testosterone levels decreased to normal range soon after surgery. She was put on mitotane treatment as adjuvant therapy, but due to side effects, we were unable to up-titrate the dose and she never achieved serum mitotane dosage above the desired 14 µg/mL. The patient remained in good health without any local recurrence or metastasis until 5 years after surgery, when increased levels of estradiol (81 pg/mL - 2.5 times above upper normal limit) and testosterone (170 ng/dL - 2.1 times above upper normal limit) were detected. MRI revealed a retroperitoneal nodule measuring 1.8 × 1.2 cm. The pathological finding confirmed the recurrence of the estrogen-secreting ACC with a Weiss' score of 6. After the second procedure, patient achieved normal estrogen and androgen serum levels and since then she has been followed for 3 years. The overall survival was 8 years after the diagnosis. In conclusion, although extremely rare, a diagnosis of an estrogen-secreting ACC should be considered as an etiology in postmenopausal women presenting with bilateral breast enlargement, genital bleeding and increased pure or prevailing estrogen secretion. LEARNING POINTS: Estrogen-secreting adrenocortical carcinomas are exceedingly rare in adults and account for 1-2% of adrenocortical carcinomas. Estrogen-secreting adrenal tumors can be present in females, but are even more rare, we found few cases described in the literature. In women, they present with precocious puberty or postmenopausal bleeding. Feminization in the context of an adrenal tumor is considered almost pathognomonic of malignancy. Feminizing ACCs tend to be larger and with worse prognosis compared with nonfeminizing ACCs.
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Recent evidence shows that chronic ethanol consumption increases endothelin (ET)-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D), and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.
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Alcoolismo/metabolismo , Diabetes Mellitus Experimental/metabolismo , Endotelina-1/análise , MicroRNAs/análise , Pênis/metabolismo , Receptor de Endotelina A/análise , Receptor de Endotelina B/análise , Alcoolismo/complicações , Alcoolismo/fisiopatologia , Animais , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/fisiopatologia , Imuno-Histoquímica , Masculino , Pênis/fisiopatologia , Ratos , Ratos WistarRESUMO
The purpose of this study was to investigate the relationship between cyclin D1 expression and clinicopathological parameters in patients with prostate carcinoma. We assessed cyclin D1 expression by conventional immunohistochemistry in 85 patients who underwent radical prostatectomy for prostate carcinoma and 10 normal prostate tissue samples retrieved from autopsies. We measured nuclear immunostaining in the entire tumor area and based the results on the percentage of positive tumor cells. The preoperative prostate-specific antigen (PSA) level was 8.68±5.16 ng/mL (mean±SD). Cyclin D1 staining was positive (cyclin D1 expression in REPLACE_GT5% of tumor cells) in 64 cases (75.4%) and negative (cyclin D1 expression in ≤5% of tumor cells) in 21 cases (including 15 cases with no immunostaining). Normal prostate tissues were negative for cyclin D1. Among patients with a high-grade Gleason score (≧7), 86% of patients demonstrated cyclin D1 immunostaining of REPLACE_GT5% (PREPLACE_LT0.05). In the crude analysis of cyclin D1 expression, the high-grade Gleason score group showed a mean expression of 39.6%, compared to 26.9% in the low-grade Gleason score group (PREPLACE_LT0.05). Perineural invasion tended to be associated with cyclin D1 expression (P=0.07), whereas cyclin D1 expression was not associated with PSA levels or other parameters. Our results suggest that high cyclin D1 expression could be a potential marker for tumor aggressiveness.
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Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma/genética , Ciclina D1/genética , Neoplasias da Próstata/genética , Carcinoma/diagnóstico , Carcinoma/cirurgia , Imuno-Histoquímica , Gradação de Tumores , Prognóstico , Prostatectomia , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/cirurgia , Coloração e Rotulagem , Estatística como AssuntoRESUMO
The purpose of this study was to investigate the relationship between cyclin D1 expression and clinicopathological parameters in patients with prostate carcinoma. We assessed cyclin D1 expression by conventional immunohistochemistry in 85 patients who underwent radical prostatectomy for prostate carcinoma and 10 normal prostate tissue samples retrieved from autopsies. We measured nuclear immunostaining in the entire tumor area and based the results on the percentage of positive tumor cells. The preoperative prostate-specific antigen (PSA) level was 8.68±5.16 ng/mL (mean±SD). Cyclin D1 staining was positive (cyclin D1 expression in >5% of tumor cells) in 64 cases (75.4%) and negative (cyclin D1 expression in ≤5% of tumor cells) in 21 cases (including 15 cases with no immunostaining). Normal prostate tissues were negative for cyclin D1. Among patients with a high-grade Gleason score (≥7), 86% of patients demonstrated cyclin D1 immunostaining of >5% (P<0.05). In the crude analysis of cyclin D1 expression, the high-grade Gleason score group showed a mean expression of 39.6%, compared to 26.9% in the low-grade Gleason score group (P<0.05). Perineural invasion tended to be associated with cyclin D1 expression (P=0.07), whereas cyclin D1 expression was not associated with PSA levels or other parameters. Our results suggest that high cyclin D1 expression could be a potential marker for tumor aggressiveness.
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Carcinoma/genética , Ciclina D1/genética , Neoplasias da Próstata/genética , Idoso , Carcinoma/diagnóstico , Carcinoma/cirurgia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Prognóstico , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/cirurgia , Coloração e Rotulagem , Estatística como AssuntoRESUMO
INTRODUCTION: Renal cell carcinoma (RCC) is a family of distinct tumors, and a variety of molecules have been evaluated as prognostic markers for RCC. Cyclin D1, a cell cycle regulator, is overexpressed in several primary tumors. OBJECTIVE: To evaluate cyclin D1 expression as a prognostic marker in RCC. METHOD: In total, 109 tumor specimens from patients with RCC were obtained from 2005 to 2010 at Hospital das Clínicas--Ribeirão Preto School of Medicine--USP, Brazil, and submitted to immunohistochemical analysis along with seven normal kidney tissue samples. RESULTS: All of the normal kidney samples lacked cyclin D1 immunohistochemical staining. In addition, there was lower protein expression in the papillary and chromophobe RCC samples. Patients with cyclin D1(low) tumors (≤ 30 % positive cells) showed worse clinical outcome (p = 0.03), lower survival without metastasis and/or death by RCC (p = 0.03), high nuclear grade (p = 0.001), larger tumor size (p = 0.01), presence of symptoms at diagnosis (p = 0.04), necrosis (p = 0.004) and sarcomatoid morphology (p = 0.04). After multivariate analysis, cyclin D1 was not an independent significant factor for worse outcome; however, it improved the accuracy of the adopted prognostic system. The analysis performed for clear cell RCC alone showed similar statistical significance to that of the total cases. CONCLUSIONS: Cyclin D1 protein was overexpressed in RCC. The types of RCC appear to exhibit different immunohistochemical staining patterns for cyclin D1; high protein expression was related to good clinical outcome and to most known favorable prognostic factors. Further investigations are necessary to reveal which mechanisms lead to cyclin D1 accumulation in neoplastic cells.
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Biomarcadores Tumorais/análise , Carcinoma de Células Renais/química , Ciclina D1/análise , Neoplasias Renais/química , Neoplasias Renais/patologia , Rim/química , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/secundário , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Taxa de Sobrevida , Carga Tumoral , Adulto JovemRESUMO
BACKGROUND: Damage provoked by ischemia in renal transplants is difficult to quantify. To determine whether a donated organ is fit for transplantation. We sought to correlate the findings of fluorescence spectroscopy (FS) with histologic evidence of ischemic injury and organ viability. METHODS: Kidneys of 33 rats were submitted to FS of the upper and lower poles as well as the middle third. Excitation was generated by the laser's wavelengths of 408, 442, and 532 nm. Rats were randomized into groups with the 30, 60, and 120 minutes warm ischemia before analysis by FS, that was repeated at 5 minutes after reperfusion. RESULTS: FS results in the reperfusion phase correlated with ischemia time and degree of histologic injury. After 60 or 120 minutes of ischemia, the excitation lasers of 532 and 442 nm resented a significant negative correlation coefficient with the histological grade (r = -0.61 and r = -0.73, respectively). CONCLUSIONS: There was a strong correlation between FS and histologic changes only in the reperfusion phase after renal ischemia. The method was thus unable to assess the viability of organs before transplantation.
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Rim/irrigação sanguínea , Traumatismo por Reperfusão/diagnóstico , Espectrometria de Fluorescência/métodos , Animais , Masculino , Ratos , Ratos WistarRESUMO
We examined the expression of anti-apoptotic genes (XIAP and Bcl-2) and apoptotic genes (cytochrome c, caspase-9, Apaf-1) in tissue samples of patients with superficial bladder cancer. Thirty-two bladder cancer tissue samples (8 papillary urothelial neoplasm of low malignant potential, 10 low-grade, and 14 high-grade) and 8 normal bladder tissue samples from necropsy were used for the study of gene expression by real-time PCR analysis. Analysis of the expression of apoptotic gene constituents of an apoptosome demonstrated an increase in Apaf-1 expression in the three tumor grades when compared with the control (P < 0.01, P < 0.05, and P < 0.01), low expression of caspase-9 in all groups (P < 0.05), and an increase in cytochrome c expression in all tumor grades in relation to the control, although without statistically significant difference. The expression of anti-apoptotic genes revealed an increase in XIAP expression in all tumor grades in relation to the control, although without statistically significant difference, and low expression of Bcl-2 in all tumor grades and the control (P < 0.05). The results proved that there is low evidence of apoptotic activity by the intrinsic pathway, demonstrated by the low expression of caspase-9 and considerable increase in XIAP expression, which may render these genes potential therapeutic targets in bladder cancer treatment.
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Apoptose/genética , Regulação Neoplásica da Expressão Gênica , Transdução de Sinais , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Fator Apoptótico 1 Ativador de Proteases/genética , Fator Apoptótico 1 Ativador de Proteases/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Citocromos c/genética , Citocromos c/metabolismo , Perfilação da Expressão Gênica , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Erectile dysfunction (ED) may reflect vascular alterations associated with imbalanced matrix metalloproteinases (MMPs) activities. However, no previous study has compared MMPs levels in ED patients with those found in healthy subjects. We measured the circulating MMP-2, MMP-9, TIMP-1 and TIMP-2 levels in ED patients, with or without diabetes mellitus (DM), and in healthy controls. We studied 28 healthy men (control group), 35 men with ED (ED group), and 33 men with ED and DM (ED/DM group). MMP-2, MMP-9, TIMP-1 and TIMP-2 plasma levels were measured by enzyme-linked immunosorbent assay and zymography. We found no differences in MMP-9 levels (P>0.05) among groups. However, while patients in the ED group had similar TIMP-1 levels compared with those found in the control group, we found higher TIMP-1 levels and lower MMP-9/TIMP-1 ratios in the ED/DM group compared with controls (P<0.05). While both groups of patients (ED and ED/DM) had slightly lower MMP-2 levels compared with controls (P<0.05), we found no differences in TIMP-2 levels among the study groups (P>0.05), and no differences in MMP-2/TIMP-2 ratios (P>0.05). We found evidence indicating lack of significant alterations in circulating net MMP-9 and MMP-2 activities in patients with ED, and lower net MMP-9 activity in diabetic patients with ED.
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Inibidores Enzimáticos/sangue , Disfunção Erétil/enzimologia , Inibidores de Metaloproteinases de Matriz , Metaloproteinases da Matriz/sangue , Adulto , Idoso , Complicações do Diabetes , Diabetes Mellitus/enzimologia , Disfunção Erétil/complicações , Humanos , Masculino , Metaloproteinase 2 da Matriz/sangue , Metaloproteinase 9 da Matriz/sangue , Pessoa de Meia-Idade , Inibidor Tecidual de Metaloproteinase-1/sangue , Inibidor Tecidual de Metaloproteinase-2/sangueRESUMO
BACKGROUND: Kidney transplantation is widely recognized as the best treatment in patients who require renal replacement therapy. Although considered a clinical and surgical triumph, it is also a source of frustration because of lack of donor organs and the growth of waiting lists. Strategies need to be developed to increase the supply of organs. One measure is use of expanded criteria for donation. OBJECTIVE: To evaluate the effect of donor age on cadaver graft survival. MATERIALS AND METHODS: We reviewed the medical records for 454 patients who underwent kidney transplantation with cadaver donors from April 1987 to December 2003. RESULTS: Donor age had a significant effect on kidney transplant survival. Survival of grafts from donors aged 16 to 40 years (mean, 143.30 months) was significantly greater compared with that of grafts from donors older than 40 years (66.46 months) (P = .005). The HLA matching and cold ischemia time did not significantly affect transplant survival (P = .98 and P = .16, respectively). CONCLUSIONS: Kidneys from cadaver donors older than 40 years significantly compromised graft survival, generating a negative effect via early return of recipients to waiting lists and increasing the rate of repeat transplantation, risk of death, and unnecessary costs.
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Fatores Etários , Transplante de Rim/mortalidade , Seleção de Pacientes , Doadores de Tecidos/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Sobrevivência de Enxerto , Antígenos HLA/imunologia , Humanos , Lactente , Transplante de Rim/imunologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento , Listas de EsperaRESUMO
BACKGROUND: Approximately 20% of urinary tract fistulas after renal allografting are complicated by urinary tract infection, which presents a therapeutic challenge. OBJECTIVE: To evaluate an option for treatment of urinary tract fistulas associated with urinary tract infection and unsuitable for minimally invasive or primary surgical urinary tract repair. PATIENTS AND METHODS: The study included 650 recipients who underwent transplantation over 17 years. Urinary leakage was initially treated with indwelling bladder catheterization. Patients with fistulas refractory to treatment underwent surgical intervention to repair the urinary tract. In patients who were not candidates for primary repair of the urinary tract, temporary urinary diversion was performed, rather than classic percutaneous or open nephrostomy, using a ureteral stent (ie, a 6F or 8F Foley catheter with the balloon placed inside the renal pelvis). RESULTS: Overall, urinary leakage occurred in 36 patients (5.5%). Conservative management was successful in 14 vesical fistulas (42.4%) and no ureteral fistulas (0%). Three patients died of sepsis during conservative treatment, before the new surgical approach. Five of 36 urinary leaks (13.9%) were managed using ureteral intubation with an 8F Foley catheter, with a success rate of 80%. CONCLUSION: Ureteral catheterization with an 8F Foley catheter is a feasible therapeutic option to treat complicated urinary tract fistulas unsuitable for primary surgical repair of the urinary tract.
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Fístula/epidemiologia , Transplante de Rim/efeitos adversos , Doenças Urológicas/epidemiologia , Cadáver , Cateterismo , Quimioterapia Combinada , Fístula/complicações , Fístula/mortalidade , Fístula/terapia , Humanos , Imunossupressores/uso terapêutico , Laparoscopia/métodos , Doadores Vivos , Estudos Retrospectivos , Taxa de Sobrevida , Doadores de Tecidos , Infecções Urinárias/complicações , Infecções Urinárias/epidemiologia , Infecções Urinárias/mortalidade , Doenças Urológicas/complicações , Doenças Urológicas/mortalidade , Doenças Urológicas/terapiaRESUMO
Renal ischemia/reperfusion (I/R) injury is one of the frequent causes of acute renal failure (ARF) due to the complex, interrelated sequence of events, that result in damage to and death of kidney cells. Cells of the proximal tubular epithelium are especially susceptible to I/R injury, leading to acute tubular necrosis, which plays a pivotal role in the pathogenesis of ARF. Several models have been explicated to assess morphological changes, including those of Jabonski et al. and Goujon et al. We compared the 2 models for histopathological evaluation of 30- or 120-minute periods of renal ischemia followed by 24-hour reperfusion in rats. Several changes were observed after application of the 2 models: proximal tubular cell necrosis, loss of brush border, vacuolization, denudation of tubular basement membrane as a consequence of flattening of basal cells, and presence of intratubular exfoliated cells in the lumen of proximal convoluted tubules at various stages of degeneration (karyorexis, kariopyknosis and karyolysis). Evaluating tubular lesions after 2 periods of experimental ischemia with light microscopy allowed us to conclude that the Goujon classification better characterized the main changes in cortical renal tubules after ischemia.
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Nefropatias/patologia , Traumatismo por Reperfusão/patologia , Animais , Membrana Basal/patologia , Modelos Animais de Doenças , Córtex Renal/patologia , Túbulos Renais/patologia , Túbulos Renais Proximais/patologia , Necrose/patologia , Ratos , Ratos WistarRESUMO
Ischemia-reperfusion injury is the major cause of organ dysfunction or even nonfunction following transplantation. It can attenuate the long-term survival of transplanted organs. To evaluate the severity of renal ischemia injury determined by histology, we applied laser- (442 nm and 532 nm) induced fluorescence (LIF), mitochondria respiration, and membrane swelling to evaluate 28 Wistar rats that underwent left kidney warm ischemia for 20, 40, 60, or 80 minutes. LIF performed before ischemia (control) was repeated at 20, 40, 60, and 80 minutes thereafter. We harvested left kidney tissue samples immediately after LIF determination for histology and mitochondrial analyses: state 3 and 4 respiration, respiration control rate (RCR), and membrane swelling. The association of optic spectroscopy with histological damage showed: LIF, 442 nm (r2 = 0.39, P < .001) and 532 nm, (r2 = 0.18, P = .003); reflecting laser/fluorescence-induced, 442 nm (r2 = 0.20, P = .002) and 532 nm (r2 = 0.004, P = .67). The associations between mitochondria function and tissue damage were: state 3 respiration (r2 = 0.43, P = .0004), state 4 respiration (r2 = 0.03, P = 0.38), RCR (r2 = 0.28, P = .007), and membrane swelling (r2 = 0.02, P = .43). The intensity of fluorescence emitted by tissue excited by laser, especially at a wave length of 442 nm, was determined in real time. Mitochondrial state 3 respiration and respiratory control ratio also exhibited good correlations with the grade of ischemic tissue damage.
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Isquemia/fisiopatologia , Mitocôndrias/fisiologia , Animais , Modelos Animais de Doenças , Fluorescência , Rim/fisiopatologia , Lasers , Mitocôndrias/patologia , Ratos , Ratos Wistar , Circulação Renal , Traumatismo por Reperfusão/fisiopatologiaRESUMO
Adrenocortical tumors (ACTs) are frequent in Brazil. The mechanisms of adrenal tumorigenesis remain poorly established; the R337H germline mutation in the p53 gene has previously been associated with ACTs in Brazilian children. We investigated the frequency and inheritance of R337H p53 mutation as well as genotype and phenotype correlation in 21 children and 5 adult patients with ACTs. DNA was extracted from peripheral blood cells and/or tumor tissue for sequencing exon 10 of the p53 gene. Nine sets of parents of patients with p53 mutation were also submitted to mutational analysis. Virilization was the most common clinical sign in children with or without Cushing's syndrome. Two members of the adult group showed asymptomatic adrenal incidentalomas, two showed virilization, and one presented with Cushing's syndrome. Sixteen children with ACTs had peripheral blood available, and twelve of them (75%) showed the heterozygous R337H p53 gene mutation. The R337H mutation was found in fifteen samples of the nineteen tumor specimens available (78.9%). Among the nine sets of parents of the patients with R337H mutation, eight showed the same mutation with heterozygosity in one of the parents. None of the parents showed ACTs or any other neoplasia at the time of the study. Only one adult patient with an ACT revealed the same R337H p53 germline mutation. There was no association between the presence of germline or tissue R337H p53 mutation and malignancy at diagnosis. We confirmed the high frequency of R337H p53 mutation in Brazilian children with sporadic ACTs. The R337H p53 mutation was inherited from one of the parents of the patients, and there was no association between the presence of this mutation and tumor malignancy in children. The founder effect of R337H p53 mutation and the role of environmental mutagens contributing to the geographical clustering and high prevalence of ACTs in Brazilian children remain to be established.
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Neoplasias do Córtex Suprarrenal/genética , Genes p53/genética , Mutação/genética , Adulto , Idoso , Brasil , Criança , Pré-Escolar , Códon/genética , DNA/biossíntese , DNA/química , DNA/genética , Éxons/genética , Feminino , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Breeding for high and low hypothermic responses to systemic administration of a serotonin1A (5-HT1A) receptor agonist (8-hydroxy-2-(di-n-propylamino)tetralin, 8-OH-DPAT) has resulted in high DPAT-sensitive (HDS) and low DPAT-sensitive (LDS) lines of rats, respectively. These lines also differ in several behavioral measures associated with stress. In the present microdialysis study we observed that basal 5-HT concentrations in the prefrontal cortex and dorsal hippocampus did not differ significantly between HDS and LDS rats. Thus, behavioral differences between the HDS and LDS lines might not be attributed to differences in basal 5-HT release. However, both lines had lower basal levels of 5-HT release than their randomly bred control group (random DPAT-sensitive, RDS) in the prefrontal cortex (mean +/- SEM, pg/20 microl, was 3.0 +/- 0.4 for LDS, 3.8 +/- 0.3 for HDS and 6.4 +/- 0.6 for RDS; F(2,59) = 5.8, P<0.005). The administration of (+/-)-fenfluramine (10 mg/kg) induced a greater increase in hippocampal 5-HT levels in HDS rats (500%) as compared with LDS (248%) or RDS (243%) rats (P<0.0001). There were no significant differences in the prefrontal cortex among lines, with a fenfluramine-induced 5-HT increase of about 900% in the three groups. This differential response to fenfluramine may be due to functional alterations of hippocampal 5-HT reuptake sites in the HDS line.
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8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Encéfalo/efeitos dos fármacos , Fenfluramina/farmacologia , Receptores de Serotonina/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Serotonina/metabolismo , Análise de Variância , Animais , Encéfalo/metabolismo , Cruzamento , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipotermia/metabolismo , Microdiálise , Ratos , Receptores 5-HT1 de Serotonina , Especificidade da EspécieRESUMO
Breeding for high and low hypothermic responses to systemic administration of a serotonin1A (5-HT1A) receptor agonist (8-hydroxy-2-(di-n-propylamino)tetralin, 8-OH-DPAT) has resulted in high DPAT-sensitive (HDS) and low DPAT-sensitive (LDS) lines of rats, respectively. These lines also differ in several behavioral measures associated with stress. In the present microdialysis study we observed that basal 5-HT concentrations in the prefrontal cortex and dorsal hippocampus did not differ significantly between HDS and LDS rats. Thus, behavioral differences between the HDS and LDS lines might not be attributed to differences in basal 5-HT release. However, both lines had lower basal levels of 5-HT release than their randomly bred control group (random DPAT-sensitive, RDS) in the prefrontal cortex (mean ± SEM, pg/20 æl, was 3.0 ± 0.4 for LDS, 3.8 ± 0.3 for HDS and 6.4 ± 0.6 for RDS; F(2,59) = 5.8, P<0.005). The administration of (±)-fenfluramine (10 mg/kg) induced a greater increase in hippocampal 5-HT levels in HDS rats (500 percent) as compared with LDS (248 percent) or RDS (243 percent) rats (P<0.0001). There were no significant differences in the prefrontal cortex among lines, with a fenfluramine-induced 5-HT increase of about 900 percent in the three groups. This differential response to fenfluramine may be due to functional alterations of hippocampal 5-HT reuptake sites in the HDS line
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Animais , Ratos , 8-Hidroxi-2-(di-n-propilamino)tetralina , Encéfalo , Fenfluramina , Receptores de Serotonina , Serotonina , Agonistas do Receptor de Serotonina , Inibidores Seletivos de Recaptação de Serotonina , Análise de Variância , Encéfalo , Cruzamento , Córtex Cerebral , Hipocampo , Hipotermia , Microdiálise , Especificidade da EspécieRESUMO
The globus pallidus (GP) is considered to be part of the basal ganglia and previous research has determined that it might be involved in feeding behavior. For example, it has been shown that the GP becomes active during feeding and that disinhibition of this nucleus, by locally injecting a GABA antagonist, is sufficient to induce feeding in a satiated rat. However, few studies have measured extracellular levels of glutamate during free feeding in the GP of rats. For this reason brain microdialysis coupled to capillary electrophoresis with laser-induced fluorescence was used to determine FTC-glutamate levels, either in the medial or lateral portion of the GP, of freely moving rats. Retrograde labeling of the neurons projecting to the two areas was also examined in an attempt to gain some insight on the identity of the neurons that released glutamate in the GP during feeding. Extracellular levels of glutamate-FTC differentially increased in both portions of the GP during a 2-min interval of free feeding. Retrograde labeling also showed that both areas received projections from different brain areas suggesting that each of the GP portions could be involved in separate aspects of the feeding behavior.
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Espaço Extracelular/metabolismo , Comportamento Alimentar/fisiologia , Globo Pálido/metabolismo , Ácido Glutâmico/metabolismo , Animais , Masculino , Ratos , Ratos WistarRESUMO
Behavioral effects of a medial prefrontal cortex (MPFC) transection were assessed in animal tests of anxiety. Social investigation and plus-maze open arm exploration increased in MPFC damaged animals relative to sham ones. MPFC lesions prevented D-amphetamine (2 mg/kg, i.p.) induced social investigation decrease and exaggerated general locomotion increase. Diazepam (1 mg/kg, i.p.) and MPFC synergistically increased open arm exploration on a second (repeated) plus-maze trial. These results suggest that the MPFC would be implicated in a generalized mechanism of warning enabling emission of appropriate responses to anxiogenic stimuli. Although, this lesion did not modify motor activity itself, the pattern of the motor activation induced by amphetamine was altered. The role of the MPFC areas in the behavioral response associated with fear is discussed.
Assuntos
Relações Interpessoais , Atividade Motora/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Ansiolíticos/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Dextroanfetamina/farmacologia , Diazepam/farmacologia , Masculino , Atividade Motora/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/lesões , Ratos , Ratos WistarRESUMO
Medial prefrontal cortex (MPFC) transection enhances social interaction in an open arena test. Social interaction enhances dopaminergic activity in the nucleus accumbens (NAC). In the present set of experiments, microdialysis probes were implanted in the NAC, and glutamate, gamma-aminobutyric acid (GABA) and dopamine (DA) were measured during electrical stimulation of the MPFC, after coronal transection caudal to the MPFC and after a systemic injection of amphetamine in transected rats. Electrical stimulation of the MPFC caused a transient enhancement of glutamate release in the NAC, no change in GABA levels and a long lasting increase in DA levels. Medial prefrontal transection did not change basal glutamate or GABA levels in the NAC, but increased basal DA levels. Amphetamine administration decreased GABA levels in medial prefrontal transected rats, had no effect on glutamate and increased DA levels more than in controls. The experiments suggest that glutamatergic activity in the accumbens decreases dopamine release. Medial prefrontal transection reduces glutamatergic tone and enhances dopamine release, which probably decreases GABAergic activity in the NAC. Presumably, GABA inhibition in the NAC enhances social interaction.
Assuntos
Dopamina/metabolismo , Ácido Glutâmico/metabolismo , Núcleo Accumbens/fisiologia , Córtex Pré-Frontal/fisiologia , Comportamento Social , Ácido gama-Aminobutírico/metabolismo , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Anfetamina/farmacologia , Animais , Estimulação Elétrica , Ácido Homovanílico/metabolismo , Masculino , Microdiálise , Núcleo Accumbens/efeitos dos fármacos , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Due to its low electrophoretic mobility, few studies have been able to measure gamma aminobutyric acid (GABA) in biological samples by means of capillary zone electrophoresis. Nevertheless, in micellar electrokinetic chromatography (MEKC) by adding a surfactant to the mobile phase separation can be carried out on the basis of the partition coefficient of the molecules rather than their electrophoretic mobility. In the present study microdialysis coupled to MEKC with laser induced fluorescence detection was used to successfully monitor GABA from cerebrospinal fluid and plasma dialysates. Moreover, we monitored changes in extracellular GABA from a human brain. Microdialysis samples were collected from a Parkinson's disease patient undergoing a thallamotomy as part of her treatment. Significant decreases in extracellular GABA were detected during high frequency electrical stimulation and following a thermolesion of the thalamus. These results demonstrate the feasibility of MEKC coupled to laser-induced fluorescence detection in resolving neutral amino acids, specifically GABA, from different human body fluids.
Assuntos
Encéfalo/metabolismo , Cromatografia Capilar Eletrocinética Micelar/métodos , Microdiálise , Ácido gama-Aminobutírico/análise , Ácido gama-Aminobutírico/sangue , Estimulação Elétrica , Eletroforese Capilar , Feminino , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Humanos , Pessoa de Meia-Idade , Doença de Parkinson/metabolismo , Doença de Parkinson/cirurgia , Tálamo/fisiologia , Tálamo/cirurgia , Ácido gama-Aminobutírico/líquido cefalorraquidianoRESUMO
Gabapentin (GP) is a new anticonvulsant used in refractory epilepsy. Few studies have monitored the drug in vivo. We report the combination of capillary electrophoresis and laser-induced fluorescence detection (CZE-LIFD) with brain microdialysis and plasma ultrafiltration in an attempt to measure GP and offer an alternative technique for pharmacokinetic studies. We found that CZE-LIFD is capable of linearly measuring 10(-7)-10(-9) M GP in a 1 nL volume. It was also demonstrated that it is possible to monitor GP in prefrontal cortex dialysates and plasma in rats. It is concluded that the method permits in vivo monitoring of the drug in pharmacological as well as in clinical studies.