The effect of low-dose naloxone infusion on plasma ACTH and LH in patients with Cushing's and Addison's diseases.

The ACTH, cortisol and LH responses to low dose (0.8 mg/h) naloxone 90 min infusion were investigated in seven patients with untreated Cushing's disease, six patients with Addison's disease and four control subjects. Naloxone had no effects on ACTH hypersecretion or normal ACTH levels. These data confirm that naloxone cannot provide additional diagnostic or therapeutic approaches in ACTH hypersecretion syndromes, mainly in Cushing's disease. The mean percentage LH levels did not significantly change during low dose naloxone in controls or patients with Cushing's and Addison's diseases. This suggests that increased endogenous opioid peptides in these diseases may not modify the LH responses to low dose of naloxone. However, since three of five adults with Cushing's disease had increased LH levels during naloxone, further studies may be indicated.

Acute effects of human growth hormone on zinc, copper, calcium and magnesium metabolism in normal subjects.

The acute effects of human growth hormone (hGH) on the metabolism of zinc, copper, calcium and magnesium ions was studied. Seven normal subjects were perfused iv with doses of 0.2 or 1.0 mg hGH over a period of 60 min. An increase in plasma zinc, calcium and magnesium, and a decrease in plasma copper levels was noted for the 0.2 mg dose, and these effects were reversed for the 1.0 mg dose although no urine changes occurred. Plasma mobilization of these ions appears to be related to their roles as essential physiological modulators for the action of hGH.

Metabolic effects of glucagon on plasma and urine zinc, copper, calcium and magnesium levels.

The present study determines the effect of glucagon on the behavior of zinc, copper, calcium and magnesium ions in human plasma and urine. Five normal adults were submitted to intravenous infusion of 2.0 mg glucagon over a period of 120 min. A decrease in plasma magnesium and copper was observed with no significant change in urine ion concentrations. We related plasma magnesium mobilization to glucagon, and copper mobilization to plasma variation in free fatty acids and albumin.

Pubertal maturation of the lh stimulatory response to clomiphene citrate in congenital virilizing adrenal hyperplasia.

To determine the LH release response to clomiphene citrate in children with virilizing congenital adrenal hyperplasia (CAH), we examined six patients with glucocorticoid-treated virilizing CAH, five girls and one boy, chonological age (CA) 4 years 2 months-15 years 9 months and bone age (BA) range 8-18 years. All the patients but one, were treated with nocturnal dexamethasone. Their ages at the onset of treatment ranged from 2 years 6 months to 13 years 8 months. An additional boy (CA = 4 years 3 months and BA = 7-8 years) was studied 10 days after removal of a virilizing adrenal adenoma. Clomiphene citrate (3mg/kg/day) was administered orally in two doses/day for 8 days. Venous blood was collected on days 0, 4, 6 and 8. Two patients were also studied in consecutive years. In three patients no increase was noted over the basal levels of LH, but in the others LH rose during clomiphene administration. In two patients studied in consecutive years, there was detectable shift of LH release pattern. The basal LH levels and the sum of responses (day 4, 6 and 8) to clomiphene citrate and particularly their decimal logarithms were statistically significantly correlated with their respective BA. These results confirm that previous prolonged exposure to elevated concentrations of adrenal sex steroids, in children with treated virilizing CAH, may induce precocious maturation of the hypothalamic pubertal mechanism of LH secretion. This maturation was closely correlated with the degree of skeletal maturation.

Luteinizing hormone secretion in men with chronic Chagas' disease.

A secrecao do hormonio luteinizante foi realizada em pacientes do sexo masculino com doenca de Chagas cronica e individuos controles sob condicoes basais (secrecao basal pulsatil) e de estimulo (testes do LH-RH e citrato de clomifene). O grupo chagasico mostrou uma maior dispersao dos niveis do LH integral em condicoes basais que os apresentados pelo grupo controle. A frequencia dos pulsos e a concentracao media de testosterona de 12 amostras por um periodo de 3 horas, foram normais. Alteracoes funcionais da secrecao do LH hipofisario seguindo-se infusoes aguda ou continua de LH-RH nao foram demonstradas. Entretanto, a liberacao de LH durante o teste do citrato de clomifene mostrou valores com maior dispersao, principalmente no 8o. dia no grupo chagasico em relacao ao controle. Esses resultados, provavelmente, sugerem a existencia de uma disfuncao hipotalamica na doenca de Chagas cronica

Secrecao basal pulsatil de hormonio luteinizante e de testosterona no homem adulto normal. / Pulsatile basal secretion of luteinizing hormone and testosterone in normal adult men

Em 10 homens adultos normais estudou-se atraves de colheitas seriadas durante 3 horas, a secrecao basal pulsatil de hormonio luteinizante (LH), procurando correlaciona-la com a da testosterona. Os resultados obtidos demonstram uma importante e significativa correlacao dos censores superiores e inferiores dos pulsos de LH entre si, sendo,em media, os primeiros 2 vezes maiores que os ultimos.Alem disso, ambos se correlacionam positivamente com a media dos niveis plasmaticos de 3 horas. Semelhante padrao de correlacao e encontrado quando se analisa a secrecao de testosterona. Estas relacoes limitariam a oscilacao dos valores individuais, de cada paciente, a um determinado intervalo de niveis hormonais, naquele periodo de estudo. No conjunto, as observacoes obtidas favorecem a ideia de que no homem adulto, em condicoes basais, a secrecao pulsatil de LH, decorrente de um ritmo ultradiano inerente ao sistema nervoso central, poderia ter alguns dos seus parametros quantitativos refletidos na secrecao de testosterona pelos testiculos

The effect of the anticonvulsants phenobarbital and diphenylhydantoin on intestinal absorption of calcium.

The effect of anticonvulsant drugs (phenobarbital and diphenylhydantoin) on the metabolic balance of calcium and on its intestinal absorption, as measured by an in situ intraluminal perfusion method, was studied in rats. The administration of these drugs produced: (a) an increase of the fecal excretion of calcium,. (b) a decrease of the intestinal absorption of calcium (45Ca). Both effects were more intense in rats treated with phenobarbital. There is evidence to suggest that the anticonvulsant drugs affect the intestinal mechanism of active transport of calcium.

The effect of the anticonvulsants phenobarbital and diphenylhydantoin on intestinal absorption of calcium.

The effect of anticonvulsant drugs (phenobarbital and diphenylhydantoin) on the metabolic balance of calcium and on its intestinal absorption, as measured by an in situ intraluminal perfusion method, was studied in rats. The administration of these drugs produced: (a) an increase of the fecal excretion of calcium,. (b) a decrease of the intestinal absorption of calcium (45Ca). Both effects were more intense in rats treated with phenobarbital. There is evidence to suggest that the anticonvulsant drugs affect the intestinal mechanism of active transport of calcium.

The effect of the anticonvulsants phenobarbital and diphenylhydantoin on intestinal absorption of calcium

The effect of anticonvulsant drugs (phenobarbital and diphenylhydantoin) on the metabolic balance of calcium and on its intestinal absorption, as measured by an in situ intraluminal perfusion method, was studied in rats. The administration of these drugs produced: (a) an increase of the fecal excretion of calcium,. (b) a decrease of the intestinal absorption of calcium (45Ca). Both effects were more intense in rats treated with phenobarbital. There is evidence to suggest that the anticonvulsant drugs affect the intestinal mechanism of active transport of calcium.