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Biomedical subjects

D Cocchi

Publications and source records attributed to D Cocchi.

At least 127 records · Page 7Linked to original sources
PubMed1980

Prolactin-releasing effect of domperidone in normoprolactinemic and hyperprolactinemic subjects.

The prolactin (PRL)-releasing effect of domperidone (DOM), a novel antidopaminergic drug which does not cross the blood-brain barrier, was investigated in normoprolactinemic subjects, in subjects with physiologic puerperal hyperprolactinemia or pathological hyperprolactinemia. DOM (4 mg i.v.), administered to 8 normoprolactinemic women, induced a clear-cut and sustained rise in plasma PRL, with peak levels occurring 15-30 min postinjection; the effect of the drug was also evident in 3 normoprolactinemic women at the dose of 0.25 mg i.v. Also in 8 puerperal women (postpartum day 2) intravenous administration of 4 mg DOM was followed by an increase in plasma PRL (51-517% of baseline levels, 15-45 min postinjection). Administration of DOM (4 mg i.v.) to 16 subjects with pathological hyperprolactinemia, evidenced the presence of 14 DOM-nonresponder (maximum percent increase of baseline PRL 48%) and 2 DOM-responder subjects. In 8 of the DOM-nonresponder subjects the existence of a pituitary tumor was established at surgery by selective removal of an adenoma (7 subjects) or a teratoma (1 subject): of the 6 subjects who did not undergo surgery, 3 had biochemical and/or radiologic evidence suggestive of a PRL-secreting tumor and 1 was acromegalic. These results indicate that DOM is capable of releasing PRL both in normoprolactinemic subjects and subjects with puerperal hyperprolactinemia. In contrast, DOM is unable to modify PRL levels in most subjects with pathological hyperprolactinemia, with proven or suspected pituitary tumors.

Adenoma↗
PubMed1980

Anomalous growth hormone responses to thyrotropin-releasing hormone and glucose in cirrhotic patients: the effect of metergoline.

The anomalous GH response to TRH or glucose loading was evaluated in patients with severe liver disease untreated or pretreated with metergoline (MCE), a potent antiserotoninergic drug. In 9 patients, injection of 400 micrograms TRH as a bolus induced a clear-cut GH rise (> 8 ng/ml), with peak levels 15-90 min post injection. Pretreatment with MCE did not modify baseline GH levels but potentiated the TRH-induced GH rise in 4 patients. In addition, 2 of 8 TRH nonresponder patients developed the anomalous GH response after MCE pretreatment. Like MCE, methysergide, another antiserotoninergic drug, potentiated the TRH-induced GH rise in 2 of 4 patients. Glucose administration (100 g, orally) induced a paradoxical rise of GH in 9 of 10 patients; after MCE, the paradoxical GH response to glucose was potentiated in 6 patients. These data provide the first experimental evidence that a derangement in brain monoamine (serotonin) function is actually involved in the occurrence of anomalous GH responses in subjects with severe liver disease.

Ergolines↗
PubMed1979

Failure of MIF-I to affect behavioral responses in patients with Parkinson's diseases under L-dopa therapy.

In eight subjects with Parkinson's disease under an optimal daily dose of L-dopa, acute administration of MIF-I (200 mg i.v.) did not ameliorate either the total disability score or the intellectual test PM 38 when evaluated in comparison with the effect induced by acute administration of a placebo. Also concomitant evaluation of the effect of MIF-I on the secretion of anterior pituitary hormones which are under dopaminergic control i.e., growth hormone and prolactin, did not reveal any potentiation of the L-dopa-induced stimulus.

Aged↗
PubMed1979

Long-term effect of ovariectomy on dopamine-stimulated adenylate cyclase in rat striatum and nucleus accumbens.

The long-term effects on dopamine-sensitive adenylate cyclase of deprivation of gonadal steroids resulting from ovariectomy were studied in extrahypothalamic areas of the brain, i.e. corpus striatum and nucleus accumbens. The results obtained show that in both central nervous system areas dopamine- and apomorphine-stimulated adenylate cyclase were significantly reduced, suggesting that the function of dopamine receptors in these areas was depressed.

Adenylyl Cyclases↗
PubMed1979

Interaction between the thyrotrophin-releasing hormone-induced growth hormone rise and dopaminergic drugs: studies in pathologic conditions of the animal and man.

A rise in plasma growth hormone (GH) after thyrotrophin-releasing hormone (TRH) and a striking reduction after dopaminergic drugs is present in acromegalic ('responder') patients. We have investigated the GH response to dopaminergic stimuli in two conditions of animals and man, which, like acromegaly, are characterized by a TRH-induced GH rise, i.e. rats with electrolytic lesions of the median eminence (ME) and patients with hepatic cirrhosis. In addition, we have studied the TRH-induced GH rise in rats with ME lesions, in the cirrhotic patients and in a group of 'responder' acromegalics before and after administration of dopaminergic drugs. In rats with ME lesions an infusion of dopamine (DA) neither modified baseline GH levels nor the TRH-induced GH rise. In five out of six cirrhotic patients oral administration of L-Dopa was followed by the usual rise in plasma GH. infusion of DA increased plasma GH levels in three out of seven cirrhotic patients and in four out of five subjects an earlier GH rise after TRH was seen. However, in the 'responder' acromegalics, the infusion of DA, besides lowering baseline plasma GH, was capable of reducing the TRH-induced GH rise. Collectively these data indicate that the TRH-induced GH rise emphasizes defects in the neurohormonal links between the central nervous system and the anterior pituitary. Instead, the paradoxical fall of GH after dopaminergic drugs appears to be a prerequisite of acromegaly and may be attributable to receptors for DA located on the tumorous tissue.

Acromegaly↗
PubMed1979

Growth hormone hyperresponsiveness to dopaminergic stimulation in Huntington's chorea.

The effect of 3 dopamine (DA) mimetic drugs, i.e. bromocriptine (Bro), apomorphine (Apo) and L-3,4-Dihydroxpenylalanine (L-dopa), was evaluated on plasma growth hormone (GH) levels in 18 patients with Huntington's chorea (HC). 27 Nonobese hospitalized patients were used as controls. Mean baseline GH levels were not altered in patients with HC. Oral administration of Bro (2.5 mg po) or L-dopa (500 mg), or subcutaneous administration of Apo (1.0 mg) resulted in a significantly greater and more prompt (Bro, L-dopa) increase in plasma GH in patients than in controls. These results suggest that presence of an altered dopaminergic regulation of GH secretion in HC.

Adult↗
PubMed1979

Ultrastructure of somatotrophs of rats with median eminence lesions: studies in basal conditions and after thyrotropin-releasing hormone stimulation.

Anterior pituitaries from female Sprague-Dawley rats (160-200 g b.w) bearing electrolytic lesions of the median eminence were qualitatively and quantitatively investigated by electron microscopy and the findings compared with those from intact animals or sham-operated controls. This study was performed in basal conditions and after stimulation with thyrotropin-releasing hormone. Animals with lesions showed a reduction of both the number of somatotrophic cells and growth hormone granules. After injection of thyrotropin-releasing hormone exocytosis of growth hormone granules from somatotrophs was frequent in rats with lesions of the median eminence but rare in sham-operated animals. The differences were statistically significant.

Animals↗