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Biomedical subjects

A Reggio

Publications and source records attributed to A Reggio.

At least 73 records · Page 4Linked to original sources
PubMed1983

Antidyskinetic properties of estrogens.

There is mounting evidence that several gonadal hormones may influence central nervous system. In particular, it has been found that estrogens display an antidopaminergic activity at the level of the extrapyramidal motor system. In this line we have investigated behavioral and biochemical parameters related to nigrostriatal DAergic function. Results obtained further indicate that estrogens display an antidopaminergic activity, by acting on nigrostriatal postsynaptic DAergic receptors. These results may suggest an antidyskinetic activity of estrogens.

Animals↗
PubMed1982

Effects of some typical and atypical antidepressants on GAD activity in various brain regions.

The AA. have investigated the effects of acute or chronic injection of typical and atypical antidepressants on the activity of the GABA--synthesizing enzyme glutamic acid decarboxylase (GAD, EC 4.1.1.15) in discrete brain regions. Very significant changes in GAD activity were only observed with sulpiride and nomifensine, two atypical antidepressants that selectively influence dopaminergic transmission and, in turn, prolactin secretion.

Animals↗
PubMed1981

[Effects of different doses of apomorphine on the glutamate decarboxylase activity of the substantia nigra and the medial basal hypothalamus].

The activity of gamma-aminobutyric acid (GABA) synthesizing enzyme glutamic acid decarboxylase (GAD, EC 4.1.1.15) was assayed in the rat substantia nigra (SN) and medial basal hypothalamus (MBH) following systemic injection of different doses of the dopamine receptor agonist apomorphine. In SN, the highest dose of apomorphine (1000 micrograms/kg) causes an increase of the GAD activity whilst an opposite effect is observed with the lowest dose (35 micrograms/kg). Results obtained in SN are in accordance with previous neurochemical and behavioural data suggesting an opposite action of high (500 micrograms/kg) and low doses (100 micrograms/kg) of apomorphine in nigro-striatal system, probably due to the existence of two classes of dopamine receptors, i.e. classical postsynaptic dopamine receptors and presynaptic inhibitory dopamine autoreceptors. In MBH, the evidence for similar effects of low and high doses of apomorphine (the decrease of GAD activity) may suggest that, as already reported, at this level only one class of dopamine receptors is present.

Animals↗
PubMed1981

[Hyperprolactinemia and catalepsy induced by haloperidol].

The effect of endogenous hyperprolactinemia induced by pituitary transplantation under the kidney capsule on haloperidol induced catalepsy was evaluated in male Wistar rats treated with two doses of the drug (500 gamma/kg; 2 mg/kg i.p.). Rats of 220 +/- 30 g received intraperitoneal injection of haloperidol. Every five minutes following drug administration the rats were assessed for catalepsy by placing the forepaw on a horizontal bar, and observed for two minutes. Data obtained show that hyperprolactinemia potentiates the cataleptic score in rats treated with dose of 500 gamma/kg i.p., while no significant difference was observed between hyperprolactinemic rats and control rats, at the dose of 2 mg/kg i.p. of haloperidol.

Animals↗
PubMed1981

Effects of chronic haloperidol and sulpiride treatment on rat nigral GABA content.

The effects of chronic haloperidol and sulpiride treatment on nigral GABA content were investigated in rats. Chronic sulpiride treatment is capable of inducing an increase in nigral GABA content whilst no significant effect is observed following chronic haloperidol treatment at the doses used. The different effects of haloperidol and sulpiride on nigral GABA content were related to the different neuropharmacological spectrum of the two drugs.

Animals↗
PubMed1981

Effects of different doses of apomorphine on GAD activity in rat substantia nigra.

The effects of different doses of the dopamine (DA) receptor agonist apomorphine on the activity of the gamma-aminobutyric acid (GABA)-synthesizing enzyme glutamic acid decarboxylase (GAD, EC 4.1.1.15) were investigated in rat substantia nigra in comparison with haloperidol and sulpiride, two DA receptor blocking agents. Results obtained show that low doses (10,35 microgram/kg, s.c.) of apomorphine induce a decrease in nigral GAD activity whilst an opposite effect is observed with the highest dose (1000 microgram/kg, s.c.). No significant change is observed following injection of the intermediate doses (100 and 500 microgram/kg, s.c.). Moreover, sulpiride at the dose used (2 mg/kg, i.p.) induces an increase in GAD activity whilst no effect follows systemic injection of the same dose of haloperidol. The results are discussed in light of recent neurochemical and behavioral data.

Animals↗