Effects of intracerebroventricular injection of d-amphetamine on metabolic, respiratory, and vasomotor activities and body temperatures in the rat.

Systemic and central administration of d-amphetamine both produced dose-dependent hypothermia in the rat at ambient temperature (Ta) 8 degrees C. The hypothermia was brought about solely by a decrease in metabolic heat production. However, at both Ta 22 and 30 degrees C, d-amphetamine produced hyperthermia accompanied by behavioral excitation.

Intracerebroventricular injection of sympathomimetic drugs inhibits both heat production and heat loss mechanisms in the rat.

The effects of intracerebroventricular (i.c.v.

Effects of Chinese herb, Huang Chin (Scutellaria baicalensis George) on thermoregulation in rats.

Intragastric administration of a Chinese herb, Huang Chin extract (Scutellaria baicalensis George), produced a dose-dependent fall in rectal temperature in conscious rats in a room the temperature of which was 22 degrees C or below. The hypothermia in response to Huang Chin application was brought about solely by cutaneous vasodilatation (as estimated by an increase in cutaneous temperatures). There were no changes in either metabolic heat production or respiratory evaporative heat loss.

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.

The role of the cholinergic system in the central control of thermoregulation in rats.

Systemic and central administration of methacholine (a synthetic choline derivative) both produced dose-dependent decreases in rectal temperature in rats at all the ambient temperatures studied. Both at room temperature (22 degrees C) and in the cold (8 degrees C), the hypothermia in response to methacholine application was brought about by both a decrease in metabolic heat production and an increase in cutaneous circulation. In the heat (29 degrees C), the hypothermia was due solely to an increase in respiratory evaporative heat loss.

Serotoninergic mechanisms of beta-endorphin-induced hypothermia in rats.

The effects of intraventricular administration of beta-endorphin on thermoregulatory responses of unanesthetized rats to different ambient temperatures (Ta) of 8, 22 and 30 degrees C were assessed. Administration of beta-endorphin produced a fall in rectal temperature at both Ta 8 and 22 degrees C. The hypothermia in response to beta-endorphin was brought about by both cutaneous vasodilation (as indicated by an increase in both the tail and the foot skin temperatures) and decreases in metabolic heat production.

Effects of gamma-hydroxybutyric acid on metabolic, respiratory and vasomotor activities and body temperature in rats.

The effects of gamma-hydroxybutyric acid (GHBA) on metabolic, respiratory and vasomotor activities and body temperature were assessed in unanesthetized rats at three different ambient temperatures (Ta) of 8, 22 and 30 degrees C. Intraperitoneal administration of GHBA produced dose-dependent hypothermia in rats at both 8 and 22 degrees C Ta. At Ta = 8 degrees C the hypothermia was brought about solely by a decrease in metabolic heat production, while at Ta = 22 degrees C the hypothermia was due to both a decrease in metabolic heat production and an increase in cutaneous circulation (as indicated by changes in tail and foot skin temperatures).

Effects of apomorphine on thermoregulatory responses of rats to different ambient temperatures.

Either systemic or central administration of apomorphine produced dose-related decreases in rectal temperature at ambient temperatures (Ta) of 8 and 22 degrees C in rats. At Ta = 8 degrees C, the hypothermia was brought about by a decrease in metabolic rate (M). At Ta = 22 degrees C, the hypothermia was due to an increase in mean skin temperature, an increase in respiratory evaporative heat loss (Eres) and a decrease in M.

Effects of stimulation of acupuncture loci Ta-Chuei (Go-14), Nei-Kuan (EH-6) and Tsu-San-Li (St-36) on thermoregulatory function of normal adults.

The effects of acupuncture stimulation on the Ta-Chuei (Go-14), Nei-Kuan (EH-6), and Tsu-San-Li (St-36) loci on thermoregulatory function were assessed in normal adults. Stimulation of acupuncture locus Ta-Chuei produced hypothermia. The hypothermia was brought about by a decrease in metabolic rate, an increase in cutaneous circulation (the back region) and perspiration.

Effects of increasing serotonergic receptor activity in brain on prostagladin E1-induced fever in rabbits.

In rabbits, increasing serotonergic receptor activity or funtional serotonin in brain with either the inhibitors of serotonin reuptake (e.g. fluoxetine and chlorimipramine) or the serotonin precursor 5-hydroxytryptophan in combination with the peripheral decarboxylase inhibitor benserazide, greatly reduced the fever induced by intraventricular prostaglandin E1.

Effects of brain serotonin alterations on hypothermia produced by chlorpromazine in rats.

Depressing functional serotonin or depleting serotonin levels in rat brains with either p-chlorophenylalanine, 5,6-dihydroxytryptamine or raphe lesions greatly enhanced hypothermia induced by chloropromazine (CPZ). Depressing the firing of raphe units or decreasing serotonin turnover in the brain with either a serotonin precursor (tryptophan) or the inhibitors of serotonin re-uptake (Lilly 1 10140 and chlorimipramine) also greatly enhanced the CPZ-induced hypothermia. The data indicate that serotonergic activity in the brain plays a role in the elaboration or modulation of CPZ hypothermia.

The effects of brain monoamine depletion on p-chlorophenyl-alanine-induced hypothermia.

I.p. administration of p-chlorophenylalanine produced a fall in rectal temperature in rats.

The effects of a decarboxylase inhibitor, benserazide, on both thermoregulation and chlorpromazine-induced hypothermia in rats.

Intraperitoneal administration of a peripheral decarboxylase inhibitor benserazide (Ro4-4602) to unanesthetized rats produced alterations in body temperature which depended on ambient temperature. In the cold, hypothermia was brought about by a decrease in metabolic heat production. At room temperature, a dose-dependent hypothermia was preceded by a slight hyperthermia.

Elevating serotonin levels in brain with 5-hydroxytryptophan produces hypothermia in rats.

The effect of the 5-hydroxytryptamine (5-HT) precursor 5-hydroxytryptophan (5-HTP) on the thermoregulatory responses of unanesthetized rats were assessed at three different ambient temperatures (Ta) of 8, 22 and 31 degrees C. Intraperitoneal administration of either 5-HTP alone or 5-HTP plus R04-4602 (the peripheral decarboxylase inhibitor) produced dose-dependent hypothermia at both Ta's of 8 and 22 degrees C. The hypothermia was brought about solely by a decrease in metabolic heat production at 8 degrees C Ta.