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Biomedical subjects

S Alagna

Publications and source records attributed to S Alagna.

At least 37 records · Page 2Linked to original sources

Effect of long-term treatment with sodium valproate on gonadotrophin and prolactin secretion in paediatric patients.

1 Luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin levels were measured in twenty paediatric patients receiving sodium valproate (30 mg/kg body weight daily) and in ten control subjects under control conditions and following LRH-TRH administration. In addition, baseline GH levels were measured in the two groups. 2 No significant differences were observed between the basal and stimulated hormone levels in the two groups. Although sodium valproate may act as anticonvulsant by increasing GABA levels in the central nervous system, the present data indicate that a central GABAergic pathway is probably not involved in the control of gonadotrophin and prolactin secretion.

Adult↗

Growth hormone (GH) secretion in hepatic encephalopathy.

Elevated plasma concentrations and abnormal secretory patterns of GH have been found in patients with cirrhosis of the liver. Displacement of brain dopaminergic monoamines by false "neurotransmitters' produced in the gut has been postulated as a cause of encephalopathy. In this study basal GH plasma levels and their response to TRH and L-DOPA were determined in thirty-nine cirrhotic patients and fifteen controls. Eleven patients had evidence of encephalopathy (Group 1), twenty-eight did not (Group 2). Both basal levels and the mean peak response to TRH were significantly higher in the cirrhotic patients that in the controls (Group 3). Peak values were moderately, but not significantly, higher in Group 1 than in Group 2. The response to L-DOPA was considerably lower in the encephalopathic patients in comparison with the subjects of both Group 2 and Group 3. This finding is consistent with depletion of active "neurotransmitters' in CNS. Our data fail to demonstrate clearly whether the paradoxical response to TRH can also be related to these abnormalities of monoamine metabolism in cirrhotics.

Adult↗

Pituitary responsiveness to gonadotrophin-releasing and thyrotrophin-releasing hormones in children receiving phenobarbitone.

The effect of long-term treatment with phenobarbitone on pituitary responsiveness to gonadotrophin-releasing hormone and thyrotrophin-releasing hormone was studied in 20 boys being treated with the drug to prevent febrile convulsions. Baseline concentrations of luteinising and follicle-stimulating hormones were reduced as well as the responses of these hormones to stimulation with gonadotrophin-releasing hormone. Baseline prolactin concentrations were raised in comparison with those in normal children. The response of prolactin to thyrotrophin-releasing hormone, however, was impaired only in the children who had been receiving the drug for a long time. Phenobarbitone had no effect on the secretion of growth hormone. Further studies should be carried out to ascertain how long these effects on pituitary function last after phenobarbitone is withdrawn and whether this interference with pituitary function modifies the child's subsequent development.

Child, Preschool↗

Inhibition of prolactin secretion by nomifensine in man.

Serum prolactin, TSH and GH levels were measured in thirty healthy volunteers in fasting conditions and following oral administration of 200 mg nomifensine. In addition, the effect of the drug on serum prolactin and TSH response to synthetic TRH was studied in twenty normal subjects. Inhibition of endogenous catecholamine reuptake by nomifensine significantly inhibited prolactin release whereas it had no effect on TSH and GH levels. Nomifensine administration had no appreciable effect on the TRH-induced release of TSH and prolactin.

Adult↗

Prolactin secretion in man following acute and long-term cimetidine administration.

In 20 patients with duodenal ulcer we measured serum prolactin levels following acute and long-term cimetidine administration. In addition, in 20 healthy volunteers we studied the effect of pre-treatment with bromocriptine, meterogline, nomifensine and cryroheptadine on cimetidine-induced prolactin release. Intravenous cimetidine stimulated prolactin secretion in patients and in normal subjects. In the latter, bromocroptine and metergoline pre-administration blunted the release of prolactin in response to iv cimetidine whereas nomifensine and cyproheptadine were ineffective. Long-term treatment with cimetidine (1.2 g daily for 3 months) had no effect on prolactin secretion in the 20 patients studied. No incidence of gynaecomastia, galactorrhoea or disorders of the menstual cycle was observed.

Adult↗

Dynamic evaluation of prolactin secretion in patients with oligospermia: effects of treatment with metergoline.

Serum prolactin levels were measured in 50 patients with oligospermia and in 20 control subjects under fasting conditions and following the administration of levodopa, pyridoxine, metoclopramide, and synthetic thyrotropin-releasing hormone. Four patients (8%) under fasting conditions had prolactin levels slightly above the normal range. However, no significant differences in prolactin behavior were detected between patients with hyperprolactinemia, patients with normal prolactin levels, and control subjects. The four patients with hyperprolactinemia were treated with metergoline, an ergoline derivative. Metergoline administration promptly reduced the prolactin levels. Spermatogenesis was restored in three patients after 4 to 5 months of treatment.

Adult↗

Piribedil inhibition of prolactin release induced by mechanical breast emptying in puerperal women.

The effects of a 5 day course of Piribedil, a dopaminergic agonist, on prolactin release evoked by mechanical breast emptying in puerperal women, was investigated. A daily dose of 75 mg. caused a significant decrease in the prolactin response to mechanical breast stimulation. Piribedil also proved clinically useful in inhibiting lactation. The role of dopaminergic mechanisms in the regulation of prolactin release induced by mechanical breast emptying are discussed.

Adult↗

Effects of long-term treatment with metergoline in patients with idiopathic oligospermia.

The effect of metergoline, an ergoline derivative with antiserotonin as well as dopaminergic properties, was studied in forty-five male patients with idiopathic oligospermia. Metergoline treatment (6 mg daily for 5 months) had no demonstrable effect on spermatogenesis; moreover, it did not influence the serum levels of LH, FSH, testosterone and oestradiol although it significantly reduced prolactin levels. It is concluded that, in all likelihood, serotonin plays little or no part in the pathogenesis of idiopathic oligospermia and that pharmacological reduction of normal prolactin levels has no therapeutic effect on this disease.

Adult↗

Enhancement of insulin-induced prolactin secretion by fluoxetine in man.

Fluoxetine hydrochloride, a specific inhibitor of serotonin reuptake, was given orally to five adult males to study its effect on fasting and insulin-stimulated release of PRL. A 3-day course of fluoxetine (30 mg daily) had no demonstrable effect on fasting PRL levels. Fluoxetine significantly enhanced insulin-induced PRL release. These data suggest that serotoninergic pathways have little or no part in the control of spontaneous PRL secretion in man, whereas they may play a role in insulin-stimulated PRL release.

Adult↗

Effect of synthetic LH-RH and hCG administration on plasma testosterone, androstenedione, and estradiol 17beta levels in normal men and in patients with idiopathic oligospermia.

Plasma testosterone, androstenedione, and estradiol 17beta levels were measured in 20 normal men and in 20 patients with idiopathic oligospermia before and after iv hCG (5,000 IU) and synthetic LH-RH (50 microgram) administration. No statistically significant differences in the concentrations of the steroids examined were detected between patients and controls either under control conditions or under exogenous and endogenous gonadotropin stimulation.

Adult↗

Cortisol secretion following nomifensine administration in normal subjects.

The effects of the oral administration of nomifensine, which inhibits endogenous cathecolamine re-uptake, on secretion of prolactin and cortisol were investigated in 12 normal subjects. In all the volunteers, a significant decrease of prolactin levels was observed following nomifensine administration. Cortisol levels were unaffected by this pharmacological treatment. The role of hypothalamic dopaminergic inhibitory system on ACTH-cortisol axis is discussed.

Adult↗

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 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↗

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↗