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A G Nasello

Publications and source records attributed to A G Nasello.

At least 19 recordsLinked to original sources
PubMed1991

A comparison of bromopride and domperidone effects on rat conditioned avoidance and motor activity.

Acute intraperitoneal administration of bromopride (BRO) and domperidone (DOMP), two dopamine D2 blockers used as antiemetics in gastroenterology, were tested in male rats for effects on motor activity and on active and inhibitory conditioned behaviour. BRO dose-dependently depressed ambulation and rearing, impairing the performance of active conditioned avoidance (CAR) even when injected prior to the retention session. It also impaired inhibitory avoidance responses (IAR). All these effects were dose-dependent. DOMP was ineffective at modifying any of the above described parameters. These results suggest that BRO exerts neuroleptic effects which are neither mediated by actions on peripheral dopamine receptors nor by increased prolactin levels. These data also suggest that DOMP is a more appropriate drug for gastroenterology.

Animals↗
PubMed1990

Avoidance behavior, prolactin, HVA and DOPAC in offspring of bromopride-treated rats.

The effects of perinatal treatments with bromopride (BRO), a dopaminergic blocking agent, on serum prolactin (PRL), striatal dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels, and active and inhibitory avoidance behavior of both sexes, were examined in adult Wistar rats. Offspring were divided into four groups depending upon the treatment received by the dams: BV--offspring of dams exposed to BRO only during pregnancy; VB--offspring of dams receiving BRO only during lactation; BB--offspring of dams treated with BRO during pregnancy and lactation; and VV--offspring of dams receiving vehicle during both periods. Active avoidance responses were reduced in males of all experimental groups. Other parameters such as inhibitory avoidance, serum PRL levels, and striatal HVA and DOPAC levels were not different from the control group. The results suggest that there is no relationship between HVA and DOPAC striatal levels, serum PRL levels and the behavioral modifications described here.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1990

The effect of LHRH on rat conditioned avoidance behavior: interaction with brain catecholamines.

LHRH (100 micrograms/kg. SC) impairs the acquisition of two-way avoidance conditioning. This is partially potentiated by pretreatment with alpha-methyltyrosine (alpha-MT; 250 mg/kg IP) or fusaric acid (10 mg/kg IP). L-DOPA (100 mg/kg IP) administered 5 h after alpha-MT partially reversed its effects. The possible roles of brain catecholamines on the behavioral effects of LHRH are analysed. Other tentative mechanisms of action are also discussed.

Animals↗
PubMed1990

Effects of chronic domperidone treatment on rat conditioned avoidance behavior.

The effects of chronic administration of domperidone (DOM), a peripherally acting anti-emetic and hyperprolactinemic D2-dopaminoceptor antagonist, on active and inhibitory conditioned behavior were tested on male and female rats. DOM (4 mg/kg) was injected ip daily either for 5 or 30 days. Although treatment for 5 days failed to affect experimental parameters, treatment for 30 days impaired the performance of active conditioned avoidance of female, but not male, rats. This effect was no longer observed 7 days after ending treatment. No effects of DOM treatment were observed on active conditioned avoidance of male rats or on inhibitory conditioned behavior of all rats. These data suggest that female rats are more susceptible to the hyperprolactinemic effects of DOM than male rats. However, an influence of estrous cycle interruption cannot be rejected.

Animals↗
PubMed1989

Perinatal bromopride treatment: effects on motor activity and stereotyped behavior of offspring.

Effects of different perinatal treatments with bromopride (BRO), a dopaminergic blocking agent, on open-field behavior and apomorphine (APO)-induced stereotypy were examined just after weaning and in adult Wistar rats. Weanling rats of mothers treated with BRO during lactation had greater general activity (24-48 hours after weaning) and higher stereotypy scores (96 hours after weaning) than pups from vehicle-treated control mothers. These results were not observed in rats of mothers treated with BRO only during pregnancy (BV group), nor was it as evident in animals of mothers treated during pregnancy and lactation (BB group). When adults, females had normal estrous cycles and the characteristic higher ambulation than males. However, males from groups BV and BB had lower ambulation frequencies than control males (VV group). The possibility that BRO interacts with the development of dopamine mechanisms in the brain at different sensitive developmental periods, and thereby influences later behavior, is discussed.

Animals↗
PubMed1989

Perinatal bromopride treatment: effects on sexual behavior of male and female rats.

Effects of different perinatal bromopride treatments on sexual behavior were examined in adult male and female rats of Wistar origin. Female rats of mothers treated with bromopride (BRO) during lactation (VB group) and during pregnancy and lactation (BB group) showed lower lordosis quotients than those of controls (VV group). Females of mothers treated with BRO only during pregnancy (BV group) showed no differences in lordosis quotient when compared to the VV group. There were no significant differences in male sexual behavior between experimental and control groups. The effect of bromopride on the control of sexual behavior is discussed.

Animals↗
PubMed1989

Effect of acute bromopride treatment on rat prolactin levels and sexual behavior.

Acute intraperitoneal administration of bromopride (BRO), a dopamine D2 blocker used as an anti-emetic drug in gastroenterology was tested in male and female rats for its effect on prolactin (PRL) serum levels and on sexual behavior. Rats that received 2.5 mg/kg BRO, the lowest dose tested, showed a maximal increase in PRL serum levels. Male rats that received 5.0 mg/kg BRO showed higher postejaculatory mount latency and postejaculatory intromission latency than controls. Rats treated with 10.0 mg/kg BRO showed higher mount latency, intromission latency, ejaculation latency, postejaculatory mount latency and a lower percentage of animals showing mount and ejaculation. Female rats that received 5.0 mg/kg BRO showed a lower lordosis quotient. The data suggest that blockade of postsynaptic dopamine D2 receptors inhibits male and female sexual behavior and that this inhibition is not related solely to the increase in PRL levels.

Animals↗
PubMed1988

Prolactin levels in male and female rats perinatally treated with bromopride.

The purpose of this study was to correlate behavioral modifications observed in perinatally bromopride-treated animals with possible changes in prolactin (PRL) serum levels. Adult male and female rats perinatally treated with bromopride during pregnancy and/or lactation were used for measuring PRL serum levels. There were no differences in hormone levels between experimental and control groups. The well known sexual dimorphism was observed, i.e. females showed higher levels of PRL than did males. Males of the same cage showed a hormone increase related to the sequence of sacrifice, i.e. the first animals to be sacrificed showed lower PRL levels than did subsequent ones. The possibility raised was that behavioral changes previously observed in rats treated perinatally with bromopride are not related to changes in PRL levels.

Animals↗
PubMed1988

Acute bromopride treatments: effects on general activity and inhibitory avoidance in rats.

Bromopride (BRO), a dopamine D2 blocker used in gastroenterology clinics, was tested acutely in rats for effects on general activity, measured in an open-field test, and on inhibitory avoidance behavior. Rats that received 2.5 and 5.0 mg/kg BRO showed lower locomotion and rearing frequencies than controls, and 5.0 mg/kg BRO blocked the inhibitory avoidance response. The data suggest that BRO may have neuroleptic effects.

Animals↗
PubMed1987

Dopaminergic supersensitivity after long-term bromopride treatment.

The effects of bromopride administration on open-field and apomorphine-induced stereotyped behavior of rats were studied. Bromopride induced a displacement to the right of the control dose-response curve constructed for apomorphine stereotypes. Withdrawal from long-term bromopride treatment induced not only a significant increase in ambulation and rearing frequencies for male rats observed in the open-field but also an increased sensitivity of both male and female animals to apomorphine. The results are interpreted as a consequence of the development of supersensitivity of central dopaminergic receptors, probably of the mesostriatal pathways.

Animals↗
PubMed1983

LHRH and rat avoidance behavior: influence of castration and testosterone.

Pretraining subcutaneous administration of a high dose of LHRH (100 micrograms/kg) to intact rats impaired acquisition of a conditioned avoidance response (CAR) in a two way shuttle box. Acquisition of a CAR was also decreased when LHRH was administered to castrated rats. LHRH antagonized the dose related impairment in acquisition and retention performance induced by testosterone in castrated animals. The results are discussed based on the interrelationships between castration, testosterone, LHRH and brain monoamines.

Animals↗
PubMed1980

TRH on rat conditioned avoidance behavior: interaction with brain catecholamines.

TRH (10 micrograms) intracerebroventricularly injected improves the acquisition of a two-day avoidance conditioning. This effect is partially antagonized by pretreatment IP with alpha-methyltyrosine (60 mg/kg) or disulfiram (300 mg/kg). L-DOPA (100 mg/kg) administered IP 2 hr after alpha-MT partially restores the facilitatory effect of the hormone. The possible roles of brain catecholamines on the behavioral effect of TRH are analysed. Other tentative mechanisms of action are also discussed.

Animals↗
PubMed1979

Prenatal amphetamine exposure: ovulation, sexual behavior and hypothalamic monoamine content in rats.

Previous observations have pointed out that amphetamine treatment during pregnancy produces behavioral and neurochemical changes in the male offspring. The present study was undertaken in order to determine whether those findings could be extended to sexual behavior, reproductive function and hypothalamic monoamine metabolism in female rats. It was found that offspring of amphetamine treated rats have greater sensitivity to estrogen and estrogen-progesterone for the induction of sexual receptivity. 5-HT content in medial hypothalamus of estrogen-progesterone treated rats was decreased with respect to controls. On the other hand the content of 5-HIAA was not different; noradrenaline levels in hypothalamus were also normal. Sex cycle duration and ovulatory phenomena were not affected.

Amphetamine↗
PubMed1978

Open-field and Lashley III maze behaviour of the offspring of amphetamine-treated rats.

Albino rats of our colony were administered 0.5 mg/kg of d,l-amphetamine sulphate or saline once daily throughout gestation beginning on day 1 of pregnancy. After delivery no other treatment was received by offspring. When adults, the pups of amphetamine-treated mothers had a higher motor activity in the open-field test measured as locomotion and rearing. In the Lashley III maze the treated group made more errors than controls in the first 4 days. After day 4 there seems to be habituation because no difference was observed in either the number of errors or the running time between the groups. These results are discussed in terms of brain catecholamines metabolism.

Amphetamine↗
PubMed1978

Brain catecholamines metabolism in offspring of amphetamine treated rats.

Previous observations have pointed out that treatment with amphetamine during pregnancy produces behavioral modifications in adulthood. In order to elucidate some possible brain biochemical mechanisms that could explain the behavioral changes observed we have determined the endogenous content of brain dopamine and noradrenaline, the in vivo rate of conversion of tyrosine-C14 in such amines and the activity of tyrosine-hydroxylase, the rate limiting enzyme in catecholamines biosynthesis. We did not observe modifications in the endogenous content of dopamine and noradrenaline but did observe an increase in the conversion rate of tyrosine-C14 in such amines and also in the tyrosine-hydroxylase activity. These results indicate that treatment with amphetamines during fetal age produces catecholamine metabolism modifications that persist throughout adulthood, although the influence of behavioral modifications of the mothers cannot be ruled out. The relationship with behavioral changes is discussed.

Amphetamine↗