RESUMEN

Introducción: El hiperparatiroidismo secundario (HPTS) es una complicación de la enfermedad renal crónica terminal (ERCT). A pesar de nuevas terapias médicas como calcimiméticos, en HPTS refractarios la paratiroidectomía (PTX) continúa siendo necesaria. Una complicación frecuente en estos pacientes posterior a la PTX es el síndrome de hueso hambriento (SHH), caracterizado por una profunda y prolongada hipocalcemia asociada a hipofosfatemia, secundaria a un excesivo aumento de su captación ósea. Una complicación menos descrita, pero con consecuencias graves e incluso fatales, es la hiperkalemia. El propósito de este trabajo consiste en enfatizar el riesgo de hiperkalemia por SHH a partir de un caso clínico, señalar los mecanismos fisiopatológicos, factores de riesgo y consideraciones terapéuticas. Caso clínico: Mujer de 35 años, con ERCT de causa desconocida, HPTS refractario con PTX total e implante de glándulas en antebrazo hace 9 años. Ingresa por recurrencia de HPTS. Cintigrama MIBI SPECT/CT® evidenció implante hiperfuncionante, indicándose PTX del injerto. Exámenes preoperatorios: calcemia 8.6 mg/dL, fosfatasas alcalinas 1115 UI/L (VN <100), PTH intacta (PTHi) 3509 pg/ml y kalemia 4.8 mEq/L. Biopsia: hiperplasia paratiroidea nodular. En postoperatorio inmediato presentó hiperkalemia de 7.1 mEq/L con cambios electrocardiográficos, requiriendo hemodiálisis de urgencia. Posteriormente desarrolló hipocalcemia, hipofosfatemia e hipomagnesemia, de difícil control. Discusión: El SHH post HPTS puede coexistir con hiperkalemia postoperatoria inmediata grave, incluso fatal si no se identifica y corrige a tiempo. El mecanismo fisiopatológico aún no está bien dilucidado. Varios factores pudieran intervenir, incluyendo aumento del metabolismo celular, traumatismo tisular, fármacos anestésicos, fluidos perioperatorios y flujo de iones transmembrana. El nivel de potasio previo a la cirugía, menor edad, género masculino, tiempo entre la última hemodiálisis y la cirugía, y duración de la PTX, son factores de riesgo para hiperkalemia postoperatoria. El conocimiento de esta grave complicación permitirá estar preparado para monitorizar y eventualmente tratar.

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Introduction: Secondary Hyperparathyroidism (SHPT) is a complication of End-Stage Renal Disease (ESRD). Although new medical therapies (i.e.calcimimetics,) parathyroidectomy (PTX) continues to be necessary in refractory cases. A well-known complication after PTX is an entity called Hungry Bone Syndrome (HBS), characterized by deep and prolonged hypocalcemia associated with hypophosphatemia, secondary to an excessive increase in bone formation. A less reported complication, but with severe or even fatal consequences, is hyperkalemia. The purpose of this work consists of emphasizing the risk of hyperkalemia in HBS, reporting a clinical case that points out the physiopathological mechanisms, risk factors, and therapeutic considerations. Clinical case: 35-year-old woman with ESRD of unknown cause with refractory SHPT with total PTX and forearm gland grafts nine years ago. She presented SHPT recurrency. MIBI SPECT/CT® scan showed a hyperfunctioning implant, indicating graft PTX. Preoperative tests: calcemia 8.6 mg/dL, phosphatemia 7.3 mg/dL, alkaline phosphatases 1115 UI/L (VN<100), intact PTH (iPTH) 3509 pg/ml and kalemia 4.8 mEq/L. Biopsy: parathyroid nodular hyperplasia. In the immediate postoperative period, she presented hyperkalemia at 7.1 mEq/L with electrocardiographic changes, requiring emergency hemodialysis. Later she developed hypocalcemia, hypophosphatemia, and hypomagnesemia of difficult control. Discussion: HBS post PTX can coexist with severe immediate postoperative hyperkalemia, which can be even fatal if not detected and corrected. The physiopathological mechanism is still not entirely elucidated. Various factors could interfere, including an increase in cell metabolism, tissue traumatism, anesthetic drugs, intraoperative fluids, and transmembrane ion flow. Preoperative potassium levels, younger age, male gender, the time elapsed between last hemodialysis and surgery, and duration of PTX are risk factors for post-surgical hyperkalemia. Knowing this severe complication will allow the medical team to be prepared for monitoring and eventually treating it.

Asunto(s)

Humanos , Femenino , Adulto , Enfermedades Óseas Metabólicas/etiología , Paratiroidectomía/efectos adversos , Hiperpotasemia/etiología , Hiperparatiroidismo Secundario/cirugía , Insuficiencia Renal Crónica/complicaciones , Hiperparatiroidismo Secundario/complicaciones

Asunto(s)

Humanos , Pirroles/uso terapéutico , Sulfonamidas/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Inhibidores de la Bomba de Protones/uso terapéutico , Reproducibilidad de los Resultados , Helicobacter pylori/efectos de los fármacos , Medicina Basada en la Evidencia , Erradicación de la Enfermedad

RESUMEN

Reconstruction of large bone defects still represents a major medical challenge. In recent years tissue engineering has developed techniques based on adult mesenchymal stem cells (MSCs) that could represent an attractive therapeutical option to treat large bone defects in the future. It has been demonstrated in various animal models that ex vivo expanded MSCs are capable of promoting the regeneration of skeletal defects after implantation. However, for the efficient regeneration of bone in tissue engineering applications, a rapid vascularization of implanted grafts is essential to ensure the survival of cells in the early post-implantational phase. A promising strategy to enhance vascularization of MSC-containing implants could consist of overexpression of the angiogenic master transcription factor Hypoxia-inducible factor 1 (Hif-1) in the MSCs in order to induce angiogenesis and support osteogenesis. In the present study, we overexpressed Hif-1α in MSCs by using recombinant adenoviruses and investigated cell-autonomous effects. Overexpression of Hif-1α enhanced proliferation, migration, cell survival and expression of pro-angiogenic genes. Other parameters such as expression of the osteogenic markers BMP-2 and RunX2 were decreased. Hif-1α overexpression had no effect on invasion, senescence and osteogenic differentiation of MSCs. Our experiments revealed multifarious effects of Hif-1α overexpression on cell-autonomous parameters. Therefore, Hif-1α overexpression may represent a therapeutic option to improve cellular functions of MSCs to treat critical sized bone defects.

Asunto(s)

Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Células Madre Mesenquimatosas/fisiología , Diferenciación Celular , Movimiento Celular , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Expresión Génica , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Neovascularización Fisiológica , Osteogénesis

RESUMEN

The initial and permanent effects of leisure noise (toy pistols, rock music) compared to broadband noise were examined in 68 guinea pigs. Auditory threshold shifts at 1.5, 2, 3, 4, 6, 8, 12 und 16 kHz were registered before and immediately after exposure as well as on days 1, 2, 3, 5,7 and 21 post-exposure using the auditory brain stem response (ABR) technique. In order to examine cilia and hair cell damage in eight cochlear frequency regions (<0,4 kHz, 0,4-0,8 kHz, 0,8-1.5 kHz, 1.5-3 kHz, 3-5 kHz, 5-11.5 kHz, 11.5-26 kHz und >26 kHz), cytocochleograms were performed immediately after exposure and on days 1, 7 and 21.Frequency dependent functional or morphological damage was found which depended on the type of trauma tested. All results were highly significant ( P<0.001). The results show that partial recovery of hearing occurred within 3 days of acute acoustic trauma induced by toy pistols and within 1 day after exposure to rock music or broadband noise. There was no further recovery of hearing within the following 18 and 20 days, respectively. Furthermore, permanent threshold shifts after exposure to rock music or broadband noise were not associated with cilia and/or hair cell damage.

Asunto(s)

Estimulación Acústica/métodos , Cóclea/patología , Cóclea/fisiopatología , Pérdida Auditiva Provocada por Ruido/fisiopatología , Pérdida Auditiva Provocada por Ruido/rehabilitación , Música , Ruido/efectos adversos , Recuperación de la Función/fisiología , Adaptación Fisiológica/fisiología , Animales , Audiometría de Tonos Puros/métodos , Umbral Auditivo , Exposición a Riesgos Ambientales/efectos adversos , Cobayas , Pérdida Auditiva Provocada por Ruido/etiología , Actividades Recreativas

RESUMEN

Fc gamma RII (CD32), the receptor for the Fc part of IgG, is responsible for the clearance of immunocomplexes by macrophages and plays a role in the regulation of antibody production by B cells. To investigate the process of immunocomplex binding in terms of stoichiometry and stability of the Fc gamma RII:IgG complex, we produced both Fc gamma RII isoforms (Fc gamma RIIa and Fc gamma RIIb) as soluble proteins in insect cells. The expressed proteins could be purified in high yields and were biologically active as judged by their ability to bind IgG. Thus, the minor glycosylation performed by the insect cells is not crucial for the binding of the usually highly glycosylated Fc gamma RII to IgG. The dissociation constant of the sFc gamma RIIa:IgG-hFc complex was determined by fluorescence titration (KD = 2.5 x 10(-)7 M). Complementary sFc gamma RIIa antagonizes immunocomplex binding to B cells. Here sFc gamma RIIa showed a comparable dissociation constant (KD = 1.7 x 10(-)7 M) which was almost 10-fold lower than the constant for Fc gamma RIIb. The stoichiometry of the FcRIIa:IgG-hFc complex was determined by equilibrium gel filtration and shows that IgG is able to bind alternatively one or two Fc gamma RII molecules in a noncooperative manner. Furthermore, in an ELISA-based assay the isotype specificity of various anti-Fc gamma RII monoclonal antibodies was measured as well as their ability to interfere with the IgG recognition through its receptors. To further investigate the molecular basis of the Fc gamma RII-ligand interaction, we crystallized Fc gamma RIIb. Trigonal crystals diffracted to 3 A and the structure solution is in progress.

Asunto(s)

Receptores de IgG/biosíntesis , Receptores de IgG/química , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Spodoptera/genética , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/farmacología , Complejo Antígeno-Anticuerpo/química , Complejo Antígeno-Anticuerpo/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Unión Competitiva/inmunología , Línea Celular , Cristalización , Cristalografía por Rayos X , Vectores Genéticos/síntesis química , Humanos , Fragmentos Fc de Inmunoglobulinas/metabolismo , Inmunoglobulina G/metabolismo , Inmunosupresores/farmacología , Fragmentos de Péptidos/biosíntesis , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Isoformas de Proteínas/biosíntesis , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/inmunología , Receptores de IgG/genética , Receptores de IgG/inmunología , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/inmunología , Solubilidad

RESUMEN

192-IgG-Saporin is an anti-neuronal immunotoxin that combines the 192 monoclonal antibody to the p75 neurotrophin receptor found on terminals and cell bodies of neurons in the cholinergic basal forebrain with the ribosome-inactivating protein saporin. Bilateral intraventricular injection of the 192-saporin produced a variety of dose-related behavioral, neurochemical, and histological alterations in adult male rats. While both the 2 micrograms and 4 micrograms dose produced comparable cholinergic hypofunction only the high dose produced behavioral changes. Behavioral deficits induced by the 4 micrograms dose of 192-saporin induced alterations in rotorod performance and reactivity on the hot-plate which recovered over 8 weeks. In addition, the 4 micrograms dose produced a persistent impairment in the acquisition and performance of standard Morris water maze task as well as a cued version of the task. The neurobiological alterations induced by 192-saporin involved both cholinergic and non-cholinergic systems. Both doses of 192-saporin produced a 60-80% decrease in high affinity choline transport in the hippocampus and cortex without altering this parameter in the striatum. In addition, there was a significant dose-related decrease of norepinephrine in the hippocampus in the high dose group. 192-saporin did not alter the content of dopamine, serotonin, or their metabolites in any region examined. 192-saporin also produced a loss of Purkinje cells in the cerebellum. This cell type also expresses the p75 receptor and appears to be a target for intraventricular 192-saporin. This complex interplay of factors makes the i.c.v. model of 192-saporin very problematic for studying the functional properties of the cholinergic basal forebrain. However, recent data suggest that injection of 192-saporin directly into components of the cholinergic basal forebrain can be used to further elaborate the function of this brain system and to model disorders of cholinergic hypofunction such as Alzheimer's disease.

Asunto(s)

Fibras Colinérgicas/efectos de los fármacos , Inmunotoxinas/farmacología , Locomoción/efectos de los fármacos , N-Glicosil Hidrolasas , Proteínas de Plantas/farmacología , Animales , Relación Dosis-Respuesta a Droga , Hipocampo/efectos de los fármacos , Hipocampo/ultraestructura , Inyecciones Espinales , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción/efectos de los fármacos , Proteínas Inactivadoras de Ribosomas Tipo 1 , Saporinas , Factores de Tiempo

RESUMEN

Rats were given a single gavage of trimethyltin chloride (TMT) providing a dose of 0, 4.3, or 6.7 mg/kg of alkyltin. Gross changes in brain structures were quantified and analyzed statistically. Behavioral and functional measures were taken to verify efficacy of TMT dose. The high dose produced transient weight loss and seizures. In the fourth week after gavage, the high dose produced hyperactivity in the residential maze and activity wheel. High and low TMT doses decreased auditory startle responsiveness. Estrus cycle was normal in all groups. Brains were sectioned and stained with the Timm stain which delimited subregions of hippocampus and connected structures and also revealed mossy fibers. Linear and areal measures were made at three positions along the septotemporal axis of Ammon's horn. The low dose produced reductions in size in a few isolated subareas of the brain. The high dose produced, at the three planes studied, extensive (15-40%) loss of tissue in Ammon's horn and structures to which Ammon's horn is interconnected--subiculum, entorhinal cortex, dentate gyrus, hilus, CA3, and CA1 region. Neocortex and caudate-putamen were unaffected. These findings suggest that a single TMT gavage may disrupt brain structures important to linking neocortex with subcortex via structures in the hippocampal region.

Asunto(s)

Encéfalo/efectos de los fármacos , Compuestos de Trimetilestaño/toxicidad , Animales , Conducta Animal/efectos de los fármacos , Encéfalo/patología , Femenino , Hipocampo/efectos de los fármacos , Hipocampo/patología , Histocitoquímica , Actividad Motora/efectos de los fármacos , Ratas , Coloración y Etiquetado

RESUMEN

The development of the acetylcholinesterase (AChE) texture of the cortex of the rat brain was studied during the first three weeks of life. The Tago technique enables visualization of both AChE+ cells and fibers with both shown in exquisite detail making quantification possible. At each age--0 (birth), 7, 14, 21 and 60 days (adult)--four brain areas were studied (cingulate, dorsal neocortex, lateral neocortex and olfactory) at each of three coronal planes in the brain (anterior, intermediate, posterior). Fiber density reached adult levels by Day 21 in cingulate cortex in intermediate and posterior planes. In other areas fiber density reached adult levels by Day 14 indicating a high rate of fiber growth during the first two weeks of life since at birth rat cortex is innervated only by a sparse AChE+ fiber invasion into neocortex in the anterior plane. Fiber density did not regress after adult levels were reached, however, cell staining showed a different pattern. At birth many lightly stained cells were seen in the olfactory cortex in all three planes, but other areas were devoid of cells. In all areas there was a peak at Day 7 in number of cells stained and in intensity of cells staining with a gradual decline in cell staining until by Day 21 very few stained cells were seen in the cortex (typical adult pattern).

Asunto(s)

Acetilcolinesterasa/metabolismo , Corteza Cerebral/enzimología , Fibras Nerviosas/enzimología , Neuronas/enzimología , Acetilcolinesterasa/análisis , Envejecimiento , Animales , Corteza Cerebral/citología , Corteza Cerebral/crecimiento & desarrollo , Masculino , Especificidad de Órganos , Ratas

RESUMEN

Phenylethylamine (PEA) has the same structure as amphetamine (AMP) except that PEA lacks a methyl group at the alpha carbon. Although these analogues produce many similar neurobehavioral actions, a previous study found that PEA did not support formation of conditioned taste aversion (CTA). Using somewhat different procedures, in the present study a transient taste aversion was seen in rats. Use of noradrenergic blocking agents to attempt to pharmacologically tailor PEA action to make it more like that of AMP did not improve efficacy to form CTA. A robust PEA-induced CTA was seen in mice even when PEA produced multiple seizures.

Asunto(s)

Condicionamiento Psicológico/efectos de los fármacos , Fenetilaminas/toxicidad , Gusto/efectos de los fármacos , Anfetamina/toxicidad , Animales , Interacciones Farmacológicas , Femenino , Masculino , Ratones , Ratas , Convulsiones/inducido químicamente , Convulsiones/psicología , Conducta Estereotipada/efectos de los fármacos

RESUMEN

Four commonly used anorectics which are amphetamine analogues were tested for their action on responsiveness in an acoustic startle test when rats were given daily IP injections adequate to produce a change in body weight. Drugs were given for 22 days. None of these drugs increased startle responsiveness as does the amphetamine parent compound. Instead, fenfluramine and phenylpropanolamine decreased startle responsiveness and phentermine and diethylpropion produced no change. There was no relationship between drug action and body weight. Partial tolerance was found for the fenfluramine action on startle and complete tolerance was found for its action on body weight gain. The fenfluramine action is compatible with the extensive literature on humans and animals indicating sedative properties.

Asunto(s)

Estimulación Acústica , Depresores del Apetito/farmacología , Dietilpropión/farmacología , Fenfluramina/farmacología , Fentermina/farmacología , Fenilpropanolamina/farmacología , Reflejo de Sobresalto/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Tolerancia a Medicamentos , Masculino , Ratas

RESUMEN

The action of the delipidization step and the type of differentiation fluid was assessed for two stains, Harris' hematoxylin and thionin, in frozen sections of rat brains. For thionin, all procedural variations used produced a blue or purple cell staining. Myelin stained red when sections were delipidized and differentiated in acetic acid, acid-formalin, or acid-alcohol. Myelin remained white when the delipidization step was omitted or when differentiation was performed in alcohol. Myelin staining was achieved with Harris' hematoxylin when sections were delipidized and were differentiated in either acid-formalin or borax-ferricyanide. The former produced red fibers against a red-purple or light purple cell background with some cell staining. The latter produced purple fibers contrasting sharply with a buff background and minimal cell staining. Cells were further accentuated in the hematoxylin techniques by a thionin counterstain.

Asunto(s)

Benzopiranos , Encéfalo/citología , Hematoxilina , Vaina de Mielina/análisis , Fenotiazinas , Coloración y Etiquetado/métodos , Animales , Femenino , Masculino , Ratas

Asunto(s)

Conducta Animal/efectos de los fármacos , Teratógenos/toxicidad , Alimentación Animal , Animales , Ritmo Circadiano , Femenino , Cinética , Dosificación Letal Mediana , Modelos Biológicos , Embarazo , Efectos Tardíos de la Exposición Prenatal , Teratógenos/metabolismo

RESUMEN

Pregnant rats were injected with 0, 6 or 10 mg/kg of methylmercuric chloride on Days 6-9 of gestation. Dams given the 10 mg/kg dose failed to deliver young or produced stillborn. External morphology was normal for rats given either the 0 or 6 mg/kg dose. Whole brains were examined from male and female rats, 21 or 90 days old. External brain dimensions were measured with calipers. Brains were sectioned at three criterion locations. A microprojector was used to project brain sections in order to measure intrastructural distances. Sections were examined with a light microscope to look for abnormalities. Various expected age-related changes were noted showing the sensitivity of the anatomical methods. Methylmercury produced hydrocephalus, decreased thickness of cerebral cortex in the parietal section and increased thickness of hippocampus in the occipital section. With these exceptions, the brains of mercury-treated rats showed normal development.

Asunto(s)

Conducta Animal/efectos de los fármacos , Encéfalo/anatomía & histología , Compuestos de Metilmercurio/toxicidad , Teratógenos/toxicidad , Envejecimiento , Animales , Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Femenino , Masculino , Tamaño de los Órganos/efectos de los fármacos , Embarazo , Efectos Tardíos de la Exposición Prenatal , Ratas , Factores Sexuales

RESUMEN

A procedure is described for treating the skull with an acidulated fluoride solution at the time of intracranial implantation of cannulas or electrodes. Fluoride has a stabilizing effect on the hydroxyapatite of bones and teeth. In our experience, fluoride treatment has reduced the incidence of dislodgment of intracranially implanted appliances.

Asunto(s)

Electrodos Implantados , Fluoruros/farmacología , Cráneo/efectos de los fármacos , Animales , Cateterismo/instrumentación , Dureza , Inyecciones Intraventriculares , Ratas

RESUMEN

In Experiment 1, rats were given a 1% lead acetate diet from Day 100 of life to the termination of the experiment. After 82 days of lead feeding behavioral tests were started. Lead exposure increased wheel-turning hyperactivity produced by food deprivation and phenylethylamine injection. Lead produced no activity change in the unchallenged condition. In the open field, lead-exposure rats were less responsive to the stimulating action of PEA and amphetamine and to the sedating action of pentobarbital. In Experiment 2, the interaction of lead with food deprivation of PEA on wheel-turning was replicated in naive animals given only a 32-day exposure. Chemical analysis was made of tissues. Ingested lead entered the brain. Regional steady-state levels of brain norepinephrine, dopamine and serotonin were not altered by lead treatment when measured following four days of starvation at a time when lead-induced behavioral change was distinct. It was concluded that pharmacological challenges on activity may be sensitive indicators of lead exposure, but the type of activity measure is critical.

Asunto(s)

Dieta , Privación de Alimentos , Plomo/administración & dosificación , Actividad Motora/efectos de los fármacos , Anfetamina/farmacología , Animales , Encéfalo/metabolismo , Dopamina/metabolismo , Plomo/metabolismo , Masculino , Norepinefrina/metabolismo , Pentobarbital/farmacología , Fenetilaminas/farmacología , Ratas , Serotonina/metabolismo

RESUMEN

Experiments were conducted to investigate the feasibility of using the pattern of saccharin and water drinking to detect acute and chronic administration of drugs and toxicants. Procedural variables were found to be crucial. When rats were naive for the saccharin drinking fluid, a single injection of LiCl or 2-deoxyglucose produced persistant saccharin aversion. Hypertonic saline produced only a transient saccharin aversion. If rats were pre-exposed to saccharin, the 2-deoxyglucose injection and hypertonic NaCl produced an increase in saccharin drinking but LiCl was without effect. Several types of chronic treatment were given to saccharin-experienced rats. Chronic 2-deoxyglucose, LiCl, and Pb administration produced gradually developing saccharin aversion and qualitatively different patterns of saccharin and water drinking. Chronic administration of hypertonic NaCl or insulin or chronic food deprivation had no impact on saccharin preference. It was concluded that patterns of saccharin and water drinking can be used to detect the administration of a drug or toxicant and perhaps even the time course of action, but may not detect a substance given previous to saccharin, perhaps because the animal cannot associate these now familiar perturbations with the novel saccharin solution. This means that existing toxic states may not be detected by using saccharin preference as a probe.

Asunto(s)

Desoxiazúcares/farmacología , Desoxiglucosa/farmacología , Conducta de Ingestión de Líquido/efectos de los fármacos , Litio/farmacología , Compuestos Organometálicos , Sacarina/administración & dosificación , Animales , Cloruros/farmacología , Humanos , Insulina/farmacología , Plomo/farmacología , Cloruro de Litio , Ratas , Solución Salina Hipertónica/farmacología , Gusto/efectos de los fármacos , Privación de Agua

RESUMEN

A time-sampling frequency analysis was made of criterion behaviors following injection of 2.5--10 mg/kg dosages of p-chloroamphetamine (PCA). Stereotypic behaviors (forepaw treading, circling, head weaving and inching) increased with increasing dosages and normal behaviors (grooming, rearing, and instances of inactivity) decreased. Composite scores of stereotypic behavior were a positive, linear function of PCA dosage. Composite scores of normal behavior showed near maximal inhibition at 5 mg/kg. Splayed hindlimbs is a reliable and sensitive indicator of PCA action, but vocalization, tremors, diarrhea and autonomic signs are not. Preinjection of PCA strongly attenuated the PCA-induec syndrome, as expected, since the preinjection should deplete brain serotonin and reduce the amount released by the second PCA injection.

Asunto(s)

Anfetaminas/farmacología , Conducta Animal/efectos de los fármacos , Serotonina/fisiología , p-Cloroanfetamina/farmacología , Animales , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Actividad Motora/efectos de los fármacos , Piloerección/efectos de los fármacos , Ratas , Conducta Estereotipada/efectos de los fármacos , Factores de Tiempo

Asunto(s)

Preferencias Alimentarias/efectos de los fármacos , Litio/farmacología , Sacarina , Gusto/efectos de los fármacos , Animales , Desoxiglucosa/farmacología , Depresión Química , Ingestión de Líquidos/efectos de los fármacos , Femenino , Insulina/farmacología , Ratas , Cloruro de Sodio/farmacología , Estimulación Química , Privación de Agua

RESUMEN

Water-deprived mice were injected with various concentrations of LiCl or NaCl 15 min before they were allowed to drink either water or 0.1% saccharin. The NaCl injections produced a dose-dependent increase in intake of both fluids: however, the higher dosages of LiCl produced a selective depression of fluid intakes. Saccharin intakes were depressed for less than one hr but water intakes were not affected. LiCl injections also depressed general activity and produced an apparent shift of water from blood into cells. The LiCl-induced depression of saccharin was not significantly influenced by extensive previous experience with the drinking fluid.

Asunto(s)

Conducta de Ingestión de Líquido/efectos de los fármacos , Litio/farmacología , Sacarina , Animales , Proteínas Sanguíneas/metabolismo , Depresión Química , Femenino , Hematócrito , Ratones , Concentración Osmolar

RESUMEN

Procedural variables are crucial in using taste aversion as a measure of lead toxicity. Rats were given saccharin and water to drink while ingesting a diet containing lead acetate (PbAc). Rats showed high preference for saccharin (over water) before lead was introduced. Saccharian preference fell during PbAc ingestion and rose when PbAc was removed from the diet suggesting that saccharin preference may correlate with the physiologic action of the toxicant. When saccharin was introduced simultaneously with PbAc aversion was almost total, but recovered with continuous PbAc exposure. When saccharin was introduced after the start of PbAc exposure saccharin aversion diminished with the duration of presaccharin PbAc exposure.

Asunto(s)

Preferencias Alimentarias/efectos de los fármacos , Plomo/toxicidad , Análisis de Varianza , Animales , Conducta Animal/efectos de los fármacos , Dieta , Masculino , Ratas , Sacarina , Gusto/efectos de los fármacos , Factores de Tiempo