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Biomedical subjects

P Preziosi

Publications and source records attributed to P Preziosi.

At least 199 records · Page 11Linked to original sources
PubMed1983

Etomidate inhibits prolactin release but not through a dopaminergic mechanism.

A short-acting non-barbiturate intravenous general anaesthetic, etomidate, when administered i.v. lowered serum prolactin levels in the rat. The effect was evident at rest, after surgical stress or after injection of 5-hydroxytryptophan. Haloperidol-induced hyperprolactinaemia was not modified. Administered via the intracerebroventricular route, etomidate strongly reduced serum prolactin levels in unanesthetized rats. Studies performed on superfused synaptosomes from brain areas rich in dopaminergic nerve endings did not show any influence of the etomidate, 10(-7) M-10(-6) M, on [3H]dopamine release. A peculiar GABA-like mechanism and/or possible interplay with serotonergic control of the prolactin release may be postulated in order to explain the suppressive effects of the drug on secretion of lactotrophs.

5-Hydroxytryptophan↗
PubMed1983

Effects of naloxone on the secretion of prolactin and corticosterone induced by 5-hydroxytryptophan and a serotonergic agonist, mCPP.

The effects of naloxone, an opiate "pure" receptor antagonist, on the release of prolactin and corticosterone in the rat were studied following the administration of the serotonin precursor 5-hydroxytryptophan or the serotonin receptor agonist (-) -m-chlorophenylpiperazine. Naloxone clearly antagonizes the release of prolactin induced by 5-hydroxytryptophan administered alone at a dosage of 50 mg/Kg/b.wt. or at dosage of 30 mg/Kg/b.wt. preceded 60 minutes before injection by the administration of the serotonin uptake blocker fluoxetine. The opiate antagonist does not modify the increase in blood level of prolactin induced by (-) -m-chlorophenylpiperazine. Naloxone itself does not reduce the increase in plasma level of corticosterone induced by 5-hydroxytryptophan, 5-hydroxytryptophan+fluoxetine or (-)-m-chlorophenylpiperazine. The results suggest that endogenous opioids may be involved in the increase in serum level of prolactin induced by 5-hydroxytryptophan and also indicate the existence of different serotonergic neurotransmitter circuits capable of modulating the release of prolactin and corticosterone. A mutual interplay between serotonergic and opiate neurons may be involved in controlling the release of prolactin, but such an interplay does not seem to occur in the secretion of corticotrophin-releasing hormone.

5-Hydroxytryptophan↗
PubMed1983

Hepatic hemangiomas on 33 patients. Evaluation by ultrasound, nuclear medicine, computed tomography and angiography.

33 cases of hepatic hemangioma evaluated by various diagnostic tools (ultrasound, nuclear medicine, computed tomography and angiography) are reported. Nuclear medicine is the least sensitive and specific (only a report of a lacunar area). Ultrasound sensitivity is very high, also for lesions below 2 cm. Specificity initially very low, is now going to increase according to the operator's experience. Computed tomography shows good sensitivity and provides typical signs of hemangiomas, especially in the largest tumors. Angiography was not demonstrated in all cases (2 false-negative in lesions below 2 cm). In fact, in smaller hemangiomas often fibrotic tissue is predominant and vascular anomalies may not appear. When surgery is not performed, ultrasound is recommended as non-invasive follow-up.

Adult↗
PubMed1982

[The value of echotomographic data in mesenteric cysts].

The Authors report a case of chylous mesenteric cyst of great size in an adult patient. They stress the diagnostic value of roentgen and sonographic findings that are determinant for a correct preoperative diagnosis. Sonography is the most important diagnostic tool; it leads to identification and localization of the mass; moreover it gives other important information about its physic composition. The various pathology that have a similar sonographic relief are discussed and differential diagnostic characters are referred.

Adult↗
PubMed1981

Carbamazepine, phenytoin and phenobarbital do not influence brain catecholamine uptake, in vivo, in male rats.

Desipramine (10 mg/kg, i.p.), a specific blocker of noradrenaline uptake, significantly antagonized the decrease of brain noradrenaline induced by an intraventricular injection of 6-hydroxydopamine (200 micrograms in 20 microliter) in rats. The depletion of brain dopamine, in 6-hydroxydopamine plus pargyline-treated rats was counteracted by nomifensine (10 mg/kg, i.p.), a drug which has been reported to markedly inhibit dopamine uptake both in vivo and in vitro. Carbamazepine (10 mg/kg, i.p.), phenytoin (200 mg/kg, orally) and phenobarbital (20 mg/kg, orally) were unable to significantly affect either the decrease of noradrenaline or the depletion of dopamine induced by 6-hydroxydopamine. These findings seem to suggest that these anticonvulsant drugs do not inhibit brain catecholamine uptake in vivo in male rats.

Animals↗
PubMed1980

Cimetidine and adrenals.

An H2-antagonist, cimetidine, reduces in the rat normal plasma corticosterone levels and strongly antagonizes their increase after cold stress. This latter effect is dose dependent. Plasma corticosterone reduction by cimetidine lasts 4 h both in normal and stress situations. Both a hypophyseal or adrenal site of action of the drug may be involved in the inhibition of adrenocortical secretion.

Adrenal Glands↗