Hypothalamic-pituitary effects of cimetidine.
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Administration, Oral↗
Biomedical subjects
G Delitala
Publications and source records attributed to G Delitala.
Effect of dopaminergic blockade on the secretion of growth hormone and prolactin in man.
Serum growth hormone (GH) response to insulin and glucagon administration was studied in 12 male and 12 female volunteers under control conditions, and under treatment with pimozide and metoclopramide. In addition, serum prolactin levels were measured during the treatment period. Pimozide and metoclopramide administration had no effect on the GH response to insulin and glucagon. In contrast, serum prolactin levels increased markedly during the treatment period. Dopaminergic blockade is unable to affect GH secretion in response to insulin and glucagon administration in man.
Adolescent↗
Effect of apomorphine and piribedil on the secretion of thyrotropin and prolactin in patients with primary hypothyroidism.
The administration of apomorphine and piribedil, two dopaminergic agents, significantly reduced thyrotropin (TSH) and prolactin levels in six female patients with primary hypothyroidism. These data provide further evidence for an inhibitory role of dopaminergic stimulation on TSH secretion.
Adult↗
Effect of clomiphene citrate on plasma levels of immunoreactive luteinizing hormone-releasing hormone, gonadotropin, and testosterone in normal subjects and in patients with idiopathic oligospermia.
The effect of clomiphene citrate on plasma immunoreactive luteinizing hormone-releasing hormone (LH-RH), gonadotropin, and testosterone levels was investigated in 10 patients with idiopathic oligospermia and in 10 normal volunteers. A daily 100-mg dose of clomiphene citrate induced a marked, significant increase in plasma immunoreactive LH-RH levels, followed by significant increments in gonadotropin and testosterone values. No significant differences were detected in LH-RH, gonadotropin, and testosterone levels between controls and patients with oligospermia either under basal conditions or during clomiphene treatment.
Adult↗
Metergoline inhibition of thyrotrophin and prolactin secretions in primary hypothyroidism.
The effect of acute oral administration of metergoline on serum thyrotrophin and prolactin levels in six patients with primary hypothyroidism was studied. Metergoline 4 mg by mouth caused a significant decrease in the concentration of serum thyrotrophin and prolactin in all subjects. There was no consistent change in serum thyroxine and triiodothyronine concentrations during the experiment. These findings suggest that metergoline inhibits prolactin and thyrotrophin secretion by a direct action on the hypothalamus or pituitary gland.
Adult↗
Inhibition of lactation and inhibition of prolactin release after mechanical breast stimulation in puerperal women given tamoxifen or placebo.
Tamoxifen was given orally to 60 puerperal women to inhibit lactation. Twenty control puerperal women were given placebo. Fifteen women receiving tamoxifen and 15 women receiving placebo were studied before, during and after the use of a breast pump under basal conditions and after five days of treatment. Tamoxifen was effective in inhibiting lactation; no rebound phenomena were observed. Its administration was free from side effects. This drug was capable of preventing the prolactin release induced by mechanical breast stimulation. Placebo failed to inhibit lactation and had no effect on prolactin release induced by the use of a breast pump.
Adult↗
Thyrotropin, prolactin and growth hormone response to synthetic thyrotropin-releasing hormone in newborn infants.
The effects of 50 microgram synthetic thyrotropin-releasing hormone (TRH) intravenously on thyrotropin (TSH), prolactin (PRL) and growth hormone (GH) levels were studied in 8 normal male newborns during the first hours of life. Mean plasma GH concentrations were similar to baseline values during the period of study; on the contrary, plasma PRL and TSH values increased in all infants after TRH administration. These data demonstrate a normal pituitary reserve of PRL and TSH in the early period of human life.
Growth Hormone↗
Effect of LRH on gonadotropin secretion in newborn male infants.
The concentrations of LH and FSH were measured in eight male newborn babies, aged 4-6 h, before and after the administration of 25 micrograms synthetic LHR. A comparison was performed with six control newborns receiving normal saline. Both LH and FSH rose significantly in all subjects after LHR administration. Their values were significantly higher than those observed during the control study. These data demonstrate sensitivity of the pituitary gonadotropes to synthetic LHR and a pubertal-type response to LH in the early hours of human life.
Follicle Stimulating Hormone↗
Dynamic evaluation of prolactin secretion during the early hours of life in human newborns.
PRL secretion was evaluated in 30 human newborns during the early hours of life. Both levodopa and pyridoxine administration failed to suppress PRL release in all subjects. Synthetic TRH elicited a constant, prompt increase in PRL levels. No significant changes were observed after somatostatin injections. These results demonstrate normal pituitary PRL reserve in newborns. The failure to respond to levodopa and pyridoxine administration might reflect partial immaturity of the pituitary dopaminergic receptors.
Humans↗
Action of somatostatin, levodopa and pyridoxine on growth hormone (GH) secretion in newborn infants.
We studied the effect of i.v. levodopa, pyridoxine and synthetic somatostatin in 28 normal babies during the first hours of life. Somatostatin caused a decrease in GH levels in all infants; in addition, both levodopa and pyridoxine infection paradoxically suppressed GH secretion in all subjects. It is concluded that in the first hours of life GH secretion can be suppressed by synthetic somatostatin as well as by levodopa and pyridoxine administration.
Depression, Chemical↗
Dopamine and T.S.H. secretion in man.
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Depression, Chemical↗
[Mazindol (AN-448): a new non-amphetamine anorectic in the treatment of exogenous obesity].
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Adolescent↗
Metergoline in the inhibition of puerperal lactation.
Seventy-eight mothers who did not want to breast-feed their newborn infants took part in a trial to assess whether metergoline could effectively suppress puerperal lactation. Metergoline 8 mg/day was given to 69 women within 24 hours after delivery and continued for five days to prevent lactation. The remaining nine women were given a course of metergoline once lactation had started. The drug was effective in both preventing and suppressing lactation. Milk secretion, engorgement, and pain were significantly reduced in women taking metergoline. Metergoline has a similar effect to bromocriptine in suppressing lactation, but its mechanism of action remains unknown.
Clinical Trials as Topic↗
Inhibition of prolactin release by metergoline administration in man.
Oral administration of metergoline, an antiserotoninergic agent, produced a fall in plasma prolactin concentrations in normal subjects. Prolactin values remained suppressed during a five day course of treatment with the drug. Serum growth hormone values were not altered significantly.
Adult↗
Suppression of human growth hormone secretion by cyproheptadine.
In order to determine whether or not a serotoninergic mechanism is involved in the secretion of the growth hormone (GH), a study was made of the effect of cyproheptadine, an antiserotonin agent, on plasma GH levels in normal children. The oral administration of cyproheptadine (12 mg daily) reduced GH responses to both L-dopa and glucagon; similarly, the mean GH response to oral glucose administration was significantly reduced after cyproheptadine administration. Plasma glucose values during the tests were not altered by cyproheptadine therapy. These results suggest that the serotoninergic mechanism might be involved in L-dopa-, glucagon-, and glucose-induced GH release.
Child↗
Effect of pimozide on levodopa-induced growth hormone release in man.
Serum growth hormone (GH) behaviour after levodopa administration was measured in twelve healthy subjects both in basal conditions and after a 4 day course of pimozide (4 mg daily), a specific blocker of dopamine (DA) receptors. In addition, fasting plasma GH was measured on the first, second and third day of treatment. No significant difference was found between GH response to levodopa in basal conditions and after pimozide; moreover, fasting GH was uninfluenced by pimozide.
Adult↗
Luteinizing hormone, follicle stimulating hormone and testosterone in normal and impotent men following LHRH and HCG stimulation.
The effect of synthetic LHRH on plasma concentrations of LH, FSH, testosterone and testosterone response to i.v. HCG was studied in fifteen normal men and in fifteen men with impotence. The mean basal concentrations of LH, FSH and testosterone in the men with impotence were not significantly different from those of the normal group. A normal response of gonadotrophins and testosterone was also observed. It is concluded that a normal pituitary sensitivity to synthetic LHRH and a normal response to endogenous and exogenous gonadotrophins exist in this particular disorder.
Adult↗
Reduction of plasma triiodothyronine (T3) induced by propranolol.
The effect of propranolol on plasma triiodothyronine (T3), thyroxine (T4) and triiodothyronine uptake by Sephadex G-25 (RT3U%) was studied in fourteen thyrotoxic patients and eight normal volunteers. 40 mg of propranolol as a single oral dose caused significant reduction in total serum T3 which began 60 min after administration. No significant changes were observed in T4 and RT3U% values. Plasma T3 levels remained suppressed during a 5 day course of treatment with propranolol. These results suggest that propranolol has a direct effect on peripheral metabolism of T3 rather than on thyroid hormone secretion.
Adult↗