Behavioural effects of naloxone in rats.

Naloxone in rats induces a behavioural syndrome closely resembling that induced by intraliquorally injected ACTH peptides. This effect is probably due to a displacement of the ACTH peptides from other receptors (e.g. opiate receptors).     

The effects of naloxone on the analgesic activities of general anaesthetics

Summary Inhaled concentrations of nitrous oxide (80%), halothane (0.5%), trichloroethylene (0.5%) and s.c. ethanol (1 ml/kg) caused similar degrees of excitation and ataxia in mice. Nitrous oxide, tricholoroethylene and ethanol caused analgesia (hot plate and writhing tests), but only that caused by nitrous oxide was antagonized by naloxone (20 mg/kg). Halothane lacked analgesic activity.     

Haloperidol produces hypothermic effects in rats

Intraperitoneal administration of either haloperidol or chlorpromazine produced hypothermia both in the cold (8 degrees C) and at room temperature (22 degrees C). The hypothermia was brought about both by a decrease in metabolic heat production and an increase in the cutaneous temperature of tail and foot skin. However, at a higher temperature (29 degrees C), there were no changes in rectal temperature and other thermoregulatory responses.     

Metabolic effects of thyroxine in infant rats

Zusammenfassung Die Behandlung 5 oder 8 Tage alter Ratten mit Thyroxin- oder TSH-Injektionen verursachte eine signifikante Stimulierung im Sauerstoffverbrauch und in der Sukzinodehydrogenase-Aktivität im Leber-, Muskel- und Gehirngewebe. Dies zeigt, dass die Inaktivität der Schilddrüse in metabolischer Kontrolle schon innerhalb von 8 Tagen nach der Geburt aufgehoben wird, wenn genügend TSH vorhanden ist.

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Supported by National Research Council for Sciences and by the University of Turku through grants to one of the authors (R.T.). The aid of MissHelka Julku is gratefully acknowledged.     

Haloperidol produces hypothermic effects in rats

Summary Intraperitoneal administration of either haloperidol or chlorpromazine produced hypothermia both in the cold (8° C) and at room temperature (22°C). The hypothermia was brought about both by a decrease in metabolic heat production and an increase in the cutaneous temperature of tail and foot skin. However, at a higher temperature (29°C), there were no changes in rectal temperature and other thermoregulatory responses.The work reported here was supported by grants from the National Science Council of Republic of China and J. Aron Charitable Foundation (New York, N.Y.). The authors are grateful to Dr C.Y. Chai for his advice during the experimentation. The generous support of Dr C.J. Shih was much appreciated by the authors. Also, we thank Dr C.D. Bloomer (Smith, Kline and French Co.) for the supply of chlorpromazine.     

Behavioural consequences of vasectomy in the mouse

Summary Vasectomy was found to have no influence on the sexual activity of male mice. Testis and seminal vesicle weights were similary not influenced by this operation although a significant increase in epididymus weight was observed.J. C. is grateful to the Ford Foundation for financial support.     

Behavioural rhythms in cultures of immatureDrosophila melanogaster

Zusammenfassung Die lokomotorische Aktivität von adultenDrosophila melanogaster zeigt einen Tagesrhythmus, der während der dreitägigen Reifungsperiode zunimmt und in Weibchen ausgeprägter ist als in Männchen. Die Periodizität der Putzhandlungen ist weniger ausgeprägt und ändert sich nicht, doch nimmt die Frequenz der Putzhandlungen bei den reifen Fliegen ab. Es wird ein reziproker Zusammenhang zwischen Putzfrequenz und sexueller Aktivität festgestellt.     

Behavioural entrainment of circadian rhythms

This paper reviews the discovery and characterization of a behavioural system for entrainment of circadian rhythms. This behavioural system depends on non-photic inputs but interacts with the light-entrainment system. Non-photic stimuli can be powerful quantitatively: behavioural events can shift rhythms by several hours. Non-photic entrainment offers scope for rephasing biological rhythms in circumstances where light input from the environment is inadequate.     

Lithium effects upon components of activity in rats

Summary When lithium chloride was administered to rats several changes occurred in a number of components of activity, some of which were sex-related. There was a reduction in both ambulatory and rearing activity and in behaviour associated particularly with the mouth and nose. The findings are related to a suggestion that lithium effects on behaviour may be more subtherthan hitherto thought.     

Behavioural entrainment of circadian rhythms

Summary This paper reviews the discovery and characterization of a behavioural system for entrainment of circadian rhythms. This behavioural system depends on non-photic inputs but interacts with the light-entrainment system. Non-photic stimuli can be powerful quantitatively: behavioural events can shift rhythms by several hours. Nonphotic entrainment offers scope for rephasing biological rhythms in circumstances where light input from the environment is inadequate.     

Lithium effects upon components of activity in rats.

When lithium chloride was administered to rats several changes occurred in a number of components of activity, some of which were sex-related. There was a reduction in both ambulatory and rearing activity and in behaviour associated particularly with the mouth and nose. The findings are related to a suggestion that lithium effects on behaviour may be more subtle than hitherto thought.     

Beneficial action of naloxone in splanchnic artery occlusion shock

Summary The effects of naloxone on mean arterial blood pressure, myocardial depressant factor (MDF) activity and survival, after splanchnic artery occlusion were studied in cats. Naloxone significantly improved survival in splanchnic artery occlusion shock and prevented the accumulation of MDF in the plasma.Supported in part by a research grant from the W. W. Smith Foundation.Acknowledgments. We gratefully acknowledge the expert technical assistance of Maureen Messenger.     

Chronic effects of nicotine on gastric secretion in vagotomized rats

Résumé La sécrétion gastrique a été mesurée dans des rats mâles avec ligature pylorique de deux heures, après 14 jours d'injections sous-cutanées de nicotine ou de NaCl. Les résultats de l'administration de nicotine furent une augmentation du volume du suc gastrique, de la production d'acide et de la production de pepsine. La vagotomie abdominale bilatérale a prévenu la stimulation gastrique secreteuse, provoquée par la nicotine.     

Diuretic effects of intraventricularly injected noradrenaline and dopamine in rats

Résumé Chez les rats on a observé l'augmentation de la diurèse provoquée par l'injection de la dopamine et de la noradrénaline dans les ventricules latéraux du cerveau. La pimozide, administré dans le péritoine, inhibe l'action de la dopamine. L'action diurétique de la noradrénaline est enrayée après injection intraventriculaire de phentolamine.     

Inhibitory effects of LHRH on ovarian LH receptors in rats]

The administration of LHRH or of its analog [D-Ala6, des-Gly-NH10(2)] LHRH ethylamide to the female rat on day 10 of gestation resulted in termination of pregnancy and in a marked decrease in ovarian LH receptors and plasma progesterone level. Asingle injection of either compound during diestrus I also led to a decrease in LH receptors. These data demonstrate the high sensitivity of the control of ovarian LH receptors by circulating gonadotrophins and suggest that the contraceptive action of pre- and postcoitally administered LHRH is mediated by negative control of LH receptors.     

Nicotine and ascorbic acid effects on cold-restraint ulcers in rats

Summary Rats were orally administered 1-ascorbic acid, nicotine, 1-ascorbic acid and nicotine, or distilled water for 10 days. Following this treatment they were fasted for 24 h and then restrained in a cold environment for 2h. Nicotine alone produced significantly more gastric ulcers than any other treatment. 1-Ascorbic acid increased ulceration relative to controls. The combined effects of 1-ascorbic acid and nicotine resulted in reduced ulcer incidence and severity. It appears that 1-ascorbic acid and nicotine do not act synergistically to augment stress-induced gastric ulcer. Supported by Natural Sciences and Engineering Research Council of Canada grant No. A 6312.