RESUMO
Resumen ANTECEDENTES: la progesterona es una hormona esteroide con participación en la ovulación, implantación, embarazo y regulación de la función uterina durante el ciclo menstrual y de otros órganos, como la glándula mamaria. Por su mecanismo de acción, la progesterona está indicada en distintos padecimientos ginecológicos y obstétricos: síndrome premenstrual, amenaza de aborto, parto pretérmino, hemorragia uterina disfuncional y mastalgia relacionada con el ciclo menstrual. OBJETIVO: evaluar la seguridad y eficacia de la progesterona en pacientes con: síndrome premenstrual, amenaza de aborto y de parto pretérmino, hemorragia uterina disfuncional, mastalgia y terapia hormonal en la menopausia. METODOLOGÍA: revisión sistemática de la evidencia científica acerca de las distintas indicaciones de la progesterona. RESULTADOS: se encontraron 92 artículos de los que se seleccionaron 41 para revisión. CONCLUSIONES: la evidencia clínica evaluada acerca de las indicaciones de la progesterona demuestra ventajas en eficacia y seguridad en los diferentes esquemas.
Abstract BACKGROUND: Progesterone is a steroid hormone involved in ovulation, implantation, pregnancy and regulation of uterine function during the menstrual cycle and other organs such as the mammary gland. Because of its mechanism of action, progesterone is indicated in different gynecological and obstetric conditions: premenstrual syndrome, threatened abortion, preterm birth, dysfunctional uterine bleeding and mastalgia related to the menstrual cycle. OBJECTIVE: To evaluate the safety and efficacy of progesterone in patients with: premenstrual syndrome, threatened abortion, preterm birth, dysfunctional uterine bleeding, mastalgia and hormone therapy in menopause. MATERIAL AND METHODS: Systematic review of scientific evidence about different indications of progesterone. RESULTS: We found 92 articles from wich 41 were selected for review. CONCLUSIONS: The clinical evidence evaluated on different indications of progesterone demonstrates advantages in efficacy and safety in different regimens.
RESUMO
OBJECTIVE: To assess the serum concentrations of estradiol (E2), estrone (E1), gonadotrophins, sex hormone-binding globulin, and lipids, and to determine degree of symptom relief after subcutaneous implantation of 25 mg estradiol in postmenopausal Mexican women. DESIGN: Fifteen postmenopausal, hysterectomized women participated in an open, observational study. Blood samples were obtained before implantation and at regular intervals during a study period of 24 weeks. Climacteric symptoms were evaluated by means of the Greene climacteric scale. Wilcoxon's test was performed on the paired results of pre-and postimplantation values. RESULTS: Serum concentrations of E2 obtained after implantation were fairly constant, remaining within the early follicular range for the entire study period of 24 weeks, and were associated with significant symptom relief. A physiological, premenopausal E2:E1 ratio was achieved. No significant metabolic changes occurred. Side effects were estrogenic in nature and no removal of implant was required. CONCLUSIONS: Subcutaneous implantation of 25 mg estradiol results in physiological, premenopausal estrogen concentrations in most women and is associated with considerable symptom relief without inducing significant adverse metabolic effects.
Assuntos
Estradiol/farmacologia , Estradiol/farmacocinética , Terapia de Reposição de Estrogênios , Pós-Menopausa/efeitos dos fármacos , Estradiol/administração & dosagem , Estradiol/sangue , Estrona/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , México , Pessoa de Meia-Idade , Pós-Menopausa/fisiologia , Próteses e Implantes , Globulina de Ligação a Hormônio Sexual/análiseRESUMO
The immunoreactivity of various LH and FSH calibration standards and recombinant preparations in the enzyme-linked immunoassay (EIA) systems for gonadotrophins developed for the Special Programme of Research in Human Reproduction of the World Health Organization (WHO) were compared. The preparations tested included three LH and two FSH pituitary standards (calibrated against LH 80/552 and 68/40 and FSH 78/549 respectively) provided with the EIA or radioimmunoassay WHO matched reagent kits, the pituitary preparation LER-907, and recombinant human LH (rhLH) and FSH (rhFSH). Simultaneous curve fitting of the EIA dose-response curves revealed no significant differences among the slopes generated by the WHO LH standards and LER-907; in contrast, no parallelism was found between the curves of rhLH and the pituitary-derived LH standards. No significant differences were found among the slopes of the curves elicited by the pituitary and recombinant FSH preparations. Each LH preparation exhibited a high degree of charge heterogeneity. Considerable variations in charge isoform distribution among the WHO LH standards, rhLH and LER-907 were also evident. In contrast, the FSH preparations were less heterogeneous and exhibited minor differences in charge distribution. Despite the existing differences in charge isoform distribution, all the pituitary-derived preparations as well as rhFSH seem appropriate for using as calibration standards in this particular EIA system.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Hormônio Foliculoestimulante/normas , Hormônio Luteinizante/normas , Organização Mundial da Saúde , Animais , Células CHO , Calibragem , Cricetinae , Relação Dose-Resposta a Droga , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Hipófise/metabolismo , Kit de Reagentes para Diagnóstico , Proteínas Recombinantes , Padrões de ReferênciaRESUMO
BACKGROUND: The present study was carried out to investigate the functional significance of the reduced dopaminergic tone in subjects affected with polycystic ovary syndrome (PCOS). METHODS: Our group evaluated the response of pituitary PRL, LH, FSH, and TSH to the administration of a single 10-mg oral dose of the dopamine (DA) receptor antagonist metoclopramide in lean (n = 7) and obese (n = 8) PCOS women and in 11 regularly cycling age- and weight-matched controls (six lean and five obese). In addition, circulating PRL bioactivity was evaluated by its mitogenic activity on a lymphoma cell bioassay. RESULTS: Oral administration of metoclopramide resulted in a significant increase in serum PRL in all subjects; however, the highest increments, regardless of body mass index (BMI), were observed in control women (p <0.005). Measurements of PRL mitogenic activity on the Nb2 lymphoma cell bioassay revealed a significant increase in the bioactive/immunoreactive (B/I) ratio of PRL under basal and stimulated conditions in obese PCOS subjects (p <0.05). Mean fasting glucose/insulin and glucose/insulin-AUC ratios were significantly lower (p <0.001) in obese PCOS when compared with all other groups. CONCLUSIONS: These data support the existence of low DA hypothalamic tone in PCOS women that is likely involved in the inappropriate LH and PRL secretion frequently seen in this syndrome. In addition, our results suggest changes in PRL bioactivity in obese PCOS that may play a role in the development of hyperinsulinemia; however, whether PRL has a functional significance in the development of the metabolic disturbances frequently seen in PCOS remains to be elucidated.
Assuntos
Antagonistas de Dopamina , Dopamina/fisiologia , Sistema Hipotálamo-Hipofisário/fisiopatologia , Hipotálamo/fisiopatologia , Metoclopramida , Síndrome do Ovário Policístico/fisiopatologia , Prolactina/metabolismo , Adolescente , Adulto , Área Sob a Curva , Glicemia/análise , Sulfato de Desidroepiandrosterona/sangue , Estradiol/metabolismo , Jejum/sangue , Feminino , Hormônio Foliculoestimulante/metabolismo , Humanos , Insulina/sangue , Hormônio Luteinizante/metabolismo , Linfoma/patologia , Obesidade/complicações , Obesidade/fisiopatologia , Síndrome do Ovário Policístico/complicações , Prolactina/sangue , Prolactina/farmacologia , Taxa Secretória/efeitos dos fármacos , Testosterona/metabolismo , Tireotropina/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
Several parameters associated with maternal behavior were quantified under laboratory conditions in New Zealand white rabbits. Digging behavior appeared earliest (8-6 days prepartum), its decline preceding the onset of straw carrying (3-1 days prepartum). Hair pulling consummated the construction of the maternal nest. Food intake significantly decreased on days 2 and 1 prepartum. On parturition day, all females spent 300-500 s with the litter while, for the rest of lactation, nursing bouts lasted 199 +/- 7 s. Milk yield increased linearly up to lactation day 19, declining thereafter. Pup weight increased linearly throughout lactation despite the decline in milk yield. Plasma estradiol (E) levels did not significantly vary across pregnancy: 60 +/- 2 pg/ml (days 10-25) and 75 +/- 6 pg/ml (day 30). The testosterone (T) levels at these times were: 200 +/- 10 and 308 +/- 0.03 pg/ml, respectively. Testosterone significantly declined from pregnancy day 30 to lactation day 1 (202 +/- 0.02 pg/ml). Progesterone (P) levels significantly declined from pregnancy day 20 (9 +/- 1 ng/ml) onwards. Progesterone levels were negligible across lactation. Thus, mother rabbits display a sequence of motor patterns and somatic events correlated with changes in plasma levels of T and P against a background of E.
Assuntos
Hormônios Esteroides Gonadais/sangue , Lactação/fisiologia , Comportamento Materno , Atividade Motora/fisiologia , Comportamento de Nidação/fisiologia , Animais , Animais Recém-Nascidos , Ingestão de Alimentos/fisiologia , Comportamento Excretor Animal/fisiologia , Estrogênios/sangue , Feminino , Masculino , Gravidez , Progesterona/sangue , Coelhos , Radioimunoensaio , Testosterona/sangue , DesmameRESUMO
PROBLEM: Experimental and clinical evidence has suggested an immunostimulatory effect of prolactin and that bromocriptine, an inhibitor of prolactin release, counteracts the actions of prolactin on the immune system. The aim of this study was to determine the impact of elevated serum prolactin levels on the immune system in patients with pathological hyperprolactinemia. METHOD: For this purpose, parameters of the cellular and humoral immune system were studied in six women with prolactinomas and one with idiopathic hyperprolactinemia. Studies were performed when serum prolactin concentrations were high as well as during different phases of the menstrual cycle when prolactin levels had been normalized through treatment with bromocriptine. RESULTS: Hyperprolactinemic subjects, when compared with six age-matched normal women, had significantly higher percentages of total lymphocytes and CD2+ cells. Elevation of CD4+ cells was also observed although to a lesser extent. Bromocriptine-treated patients, when compared with normal women were characterized by increased numbers of total lymphocytes and CD4+ cells, decreased percentage of CD8+ cells, and increased concentrations of serum IgM. These last two findings were also significantly different when compared to those observed in hyperprolactinemia. CONCLUSION: In this study we have described the changes on cellular and immune parameters in patients with hyperprolactinemia before and during bromocriptine therapy, which support the links of communications between the immune and endocrine systems in humans.
Assuntos
Bromocriptina/uso terapêutico , Hiperprolactinemia/tratamento farmacológico , Hiperprolactinemia/imunologia , Adolescente , Adulto , Feminino , Humanos , Imunoglobulinas/sangue , Imunoglobulinas/efeitos dos fármacos , Imunofenotipagem , Subpopulações de Linfócitos/efeitos dos fármacosRESUMO
OBJECTIVE: There has been increasing evidence on the mechanisms underlying the interactions between the neuroendocrine and the immune systems, particularly in animal models with relatively few information in the human. In this study, we evaluate the cellular and humoral immunity in female patients with hypopituitarism and in normal women throughout the menstrual cycle in an attempt to determine the role of pituitary and gonadal hormones on the immune system. DESIGN: Serum immunoglobulins, peripheral blood lymphocyte subsets, and serum hormones were measured in eight patients with postpartum pituitary necrosis (Sheehan's syndrome) and in six normal women along different phases of the menstrual cycle, taking advantage of the lack of pituitary function and the cyclic variations in serum hormones, respectively. RESULTS: Patients with Sheehan's syndrome had higher T lymphocytes (CD2), including helper (CD4) and suppressor (CD8) cell subpopulations and B lymphocytes (CD19) when compared with normal menstruating women. An increase of serum IgA concentrations was also observed. Normal women showed little non-statistically different changes along the menstrual cycle in peripheral blood cell parameters and in serum immunoglobulin levels. CONCLUSIONS: a) Hypopituitarism in humans, in contrast with the animal model, may associate with immune up-regulation at both cellular and humoral levels; and b) hormonal changes along the normal menstrual cycle probably do not influence in great extent the immune system.
Assuntos
Hipopituitarismo/sangue , Imunoglobulinas/sangue , Subpopulações de Linfócitos , Ciclo Menstrual/sangue , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
In the present studies we analysed the main physicochemical and biological properties of the several isoforms of human pituitary follicle-stimulating hormone (hFSH). Extracts of total anterior pituitary glycoproteins from adult donors were submitted to chromatofocusing and several forms of immunoactive hFSH with isoelectric points (pI) ranging from 7.6 to 3.8 were identified. An additional isoform was detected after passing through the chromatofocusing column a 1.0 M NaCl solution (salt peak). Each hFSH isoform or pool of neighbouring isoforms (pI value 7.6-7.1, pool I, 1.5 +/- 0.13% of total immunoactivity recovered; pI value 5.9-5.3, pool II, 8.9 +/- 1.6% of total; pI value 5.0-4.7, pool III, 14.4 +/- 1.4% of total; pI value 4.5-4.1, pool IV, 54.8 +/- 4.9% of total; pI value 3.9-3.8, pool V, 3.67 +/- 0.9% of total; salt peak, pool VI, 16.8 +/- 4.8% of total) eluted as single hFSH peaks after Sephadex G-100 exclusion chromatography (apparent Mr 60,000). Even though hFSH present within each pool was recognized by a receptor preparation, the receptor-binding activity expressed as the radioreceptor assay:radioimmunoassay (RRA/RIA) activity ratio varied with the pI value of the particular hFSH isoform tested; starting from a pI value of 5.9, the receptor-binding activity of hFSH decreased from 4.25 +/- 0.28 to 1.17 +/- 0.14, as the pI value of the corresponding isoform declined. A similar trend was observed when the potency of each isoform was assessed by an in vitro bioassay.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Hormônio Foliculoestimulante/análogos & derivados , Animais , Bioensaio , Cromatografia em Gel , Hormônio Foliculoestimulante/isolamento & purificação , Hormônio Foliculoestimulante/farmacocinética , Meia-Vida , Humanos , Ponto Isoelétrico , Masculino , Radioimunoensaio , Ensaio Radioligante , Ratos , Ratos Endogâmicos , Extratos de TecidosRESUMO
The testosterone:dihydrotestosterone ratio (T:DHT) and the antigenic marker CA 19-9 were studied in the serum of 21 male patients with pancreatic cancer and 62 controls with other gastrointestinal malignancies or benign pancreatobiliary disease. Specificity of the T:DHT ratio was 98%, significantly better than the specificity of CA 19-9 at both a 37 U/ml cutoff level (61%) and at 100 U/ml (79%). Sensitivity of the T:DHT ratio was 67%, and that of CA 19-9, 71% and 90% at the upper and lower cutoff levels, respectively. False-negative results of the T:DHT ratio were found predominantly in cases of advanced pancreatic cancer, whereas all four stage I patients had an abnormal (less than 5) T:DHT ratio. These results suggest that the T:DHT ratio is a useful marker for pancreatic cancer in males. It can be used alone or in combination with CA 19-9, and should be further evaluated in the differential diagnosis of patients with the early stages of this disease.
Assuntos
Antígenos Glicosídicos Associados a Tumores/sangue , Di-Hidrotestosterona/sangue , Neoplasias Pancreáticas/diagnóstico , Testosterona/sangue , Adulto , Idoso , Doenças Biliares/sangue , Doenças Biliares/diagnóstico , Neoplasias do Sistema Biliar/sangue , Neoplasias do Sistema Biliar/diagnóstico , Diagnóstico Diferencial , Neoplasias Gastrointestinais/sangue , Neoplasias Gastrointestinais/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatopatias/sangue , Pancreatopatias/diagnóstico , Neoplasias Pancreáticas/sangue , Sensibilidade e EspecificidadeRESUMO
The role of inhibin in the testicular function and its relation with other hormone regulation spermatogenesis have not been elucidated in the human, therefore we studied by RIA the serum concentrations of this testicular secretion product, as well as those of LH, FSH, T and E2 and their possible correlation with some parameters evaluated by spermatobioscopy (cell number, motility, morphology and immature germinal cells) in fertile, oligozoospermic and azoospermic men. We did not find significant differences in inhibin concentration between fertile and oligozoospermic males; however in the azoospermic group the mean inhibin concentration was significantly higher (722.9 +/- 137.9 U/l in the fertile men; 658.5 +/- 147.1 and 963.1 +/- 300.9 U/l in the oligozoospermic and azoospermic groups respectively), in spite of data dispersion in the 3 study groups. Among the fertile males we found a negative significant correlation between the inhibin and the LH and FSH concentrations (p less than 0.05), while in the oligozoospermic patients this negative correlation was observed with T concentration. In the fertile males inhibin also showed correlation with the sperm percentage with normal morphology and with the immature germinal cells in semen; in the oligozoospermic group this glycoprotein showed correlation with the sperm count and the germinal cells concentration. We also found correlation between testosterone and/or LH concentrations and sperm count in both groups. These results indicate modifications in the hormonal concentrations regulating the testicular function and in their relationship, in men with testicular damage, which can render a change in the mechanisms controlling this function.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Estradiol/sangue , Gonadotropinas Hipofisárias/sangue , Inibinas/sangue , Oligospermia/sangue , Testosterona/sangue , Humanos , Masculino , Oligospermia/fisiopatologia , Motilidade dos Espermatozoides , EspermatozoidesRESUMO
There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, [3H]testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with [3H]testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis.
Assuntos
Pâncreas/metabolismo , Testosterona/metabolismo , Androstenodiona/metabolismo , Animais , Di-Hidrotestosterona/metabolismo , Cães , Estradiol/metabolismo , Técnicas In Vitro , Cinética , Masculino , Baço/metabolismo , Testículo/metabolismo , TrítioRESUMO
Serum androstenedione and testosterone levels were measured in 39 male patients with pancreatic cancer, and compared with the values obtained from 37 male patients with chronic pancreatitis or benign obstructive jaundice, and with those from 36 male patients with other gastrointestinal malignancies. Mean androstenedione values were significantly higher in the pancreatic cancer patients when compared to both control groups, and mean testosterone levels were significantly lower. The testosterone/androstenedione ratio was calculated and was also found to be significantly lower in the patients with pancreatic cancer. There was no difference in this ratio or in the androstenedione or testosterone levels when comparing both control groups. In two patients with stage I pancreatic cancer, serum androstenedione and testosterone levels were significantly altered, and returned to normal values after successful resection. These results confirm previous findings indicating that there is significant derangement in the androgen profile of patients with pancreatic cancer.
Assuntos
Androstenodiona/sangue , Neoplasias Pancreáticas/sangue , Testosterona/sangue , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
Human sex hormone-binding globulin (hSHBG) is a plasma glycoprotein composed of two identical subunits. The protein, which has high affinity for testosterone and estradiol has been purified to homogeneity. In this study we have investigated, on neuraminidase-treated serum samples, the presence of genetic variations of hSHBG by polyacrylamide gel isoelectric focusing (IEF). Based on IEF analyses of 110 serum samples from adult Mexican individuals we have identified two distinct IEF-patterns. The most frequent phenotype (95.45%) was characterized by two IEF-bands with pIs of 6.50 and 6.63, respectively. In five serum samples, a different 4-band pattern with pIs of 6.50, 6.63, 6.70 and 6.76 was identified. Family studies showed that this pattern was genetically determined. The frequency of this variant was 4.55%, and the observed phenotypes were consistent with the expression of an autosomal genetic system. The estimated gene frequencies for both alleles were shown to be in genetic equilibrium. Affinity constants, binding kinetics and serum concentrations of hSHBG from individuals having a 4-band pattern were similar to those obtained in individuals with a 2-band pattern, thus suggesting that the mechanism responsible for the generation of polymorphic variants of hSHBG reported herein did not involve the steroid binding site of the molecule. These findings may be of broad interest, as other serum binding proteins express genetic variants, which may permit their further structural and functional subclassification.
Assuntos
Variação Genética , Globulina de Ligação a Hormônio Sexual/genética , Adulto , Di-Hidrotestosterona/metabolismo , Eletroforese em Gel de Poliacrilamida , Frequência do Gene , Indicadores Básicos de Saúde , Humanos , Focalização Isoelétrica , México , Neuraminidase , Linhagem , Fenótipo , Polimorfismo Genético , Globulina de Ligação a Hormônio Sexual/análiseRESUMO
We have demonstrated the selective secretion of high mol wt PRL series (big big PRL) in women with hyperprolactinemia and normal ovarian function. This observation suggests that big big PRL is immunologically similar, but biologically less active, than monomeric or little PRL. In this study we determined the molecular size heterogeneity of immunoreactive PRL in the serum from two ovulatory hyperprolactinemic women (subjects A and B) who had large amounts of serum big big PRL during a menstrual cycle and/or gestation. Serum samples obtained throughout the menstrual cycle (days 6, 10, 14, 17, 23, and 28, taking as day 1 the first day of bleeding) and pregnancy (weeks 7, 9, 11, 15, 20, 25, 30, 34, and 38) were fractionated by gel filtration chromatography. PRL was identified in column eluates by specific RIA. Two additional pregnant women, one with a bromocriptine-treated PRL-secreting adenoma (subject C), and a normal woman (subject D) were studied. Big big PRL was the predominant species throughout the different phases of the menstrual cycle in subject B, comprising 70-80% of the total immunoreactive PRL. Most of the remainder was big PRL, and little PRL was present in only small amounts (6-12%) during the luteal phase. During their pregnancies, the serum PRL in subjects A and B initially was mostly big big PRL, but later in gestation the PRL composition shifted from the high mol wt variants to little PRL. The infant's cord (subject A) and peripheral (subject B) serum at birth contained appreciable quantities of big big and big PRL, respectively. These results indicate that structural changes in PRL occur during pregnancy and the menstrual cycle which are probably influenced by the hormonal environment. In addition, the occurrence of larger mol wt PRL species in the serum of the infant of a hyperprolactinemic mother suggests that the presence of high proportions of big big PRL in the serum is genetically determined.
Assuntos
Hiperprolactinemia/sangue , Ciclo Menstrual , Ovário/fisiologia , Gravidez/sangue , Prolactina/sangue , Adulto , Cromatografia em Gel , Estradiol/sangue , Feminino , Sangue Fetal/análise , Humanos , Hiperprolactinemia/genética , Recém-Nascido , Peso Molecular , Progesterona/sangue , Prolactina/genéticaRESUMO
The mitochondrial fraction of the dog pancreas showed NAD(H)-dependent enzyme activity of 17 beta-hydroxysteroid dehydrogenase. The enzyme catalyzes oxidoreduction between androstenedione and testosterone. The apparent Km value of the enzyme for androstenedione was 9.5 +/- 0.9 microM, the apparent Vmax was determined as 0.4 nmol mg-1 min-1, and the optimal pH was 6.5. In phosphate buffer, pH 7.0, maximal rate of androstenedione reduction was observed at 37 degrees C. The oxidation of testosterone by the enzyme proceeded at the same rate as the reduction of the androstenedione at a pH of 6.8-7.0. The apparent Km value and the optimal pH of the enzyme for testosterone were 3.5 +/- 0.5 microM and 7.5, respectively.
Assuntos
17-Hidroxiesteroide Desidrogenases/metabolismo , Pâncreas/enzimologia , Androstenodiona/metabolismo , Animais , Cães , Cinética , Masculino , Frações Subcelulares/enzimologia , Testosterona/metabolismo , Termodinâmica , TrítioRESUMO
Adrenal cortex mitochondria isolated from mongrel dogs were incubated with cholesterol in the presence and absence of adriamycin (ADM). The capacity for cholesterol side chain cleavage was assessed by determining the pregnenolone yield. ADM behaves as an inhibitor of pregnenolone biosynthesis with a calculated IC50 of 110 microM. The inhibitory effect follows a dose-response relationship depending upon ADM concentration.