Thyrotropin releasing hormone‐induced hyperthermia in mice: possible involvement of adrenal and pituitary glands

Abstract

1To investigate the hyperthermic effect of thyrotropin releasing hormone (TRH) and its potentiation by exogenous catecholamines (CA), the role of the adrenal medulla and of the pituitary gland was studied in unoperated, adrenal-demedullated or hypophysectomized mice. 2 In unoperated mice, TRH 40 mg kg-l i.p. produced a hyperthermia which was accompanied by an increase in plasma noradrenaline (NA) and adrenaline (Ad). NA or Ad, both at a dose of 1 mg kg-I i.p., enhanced the TRH-induced hyperthermia.3 Adrenal demedullation suppressed the hyperthermia and the increase of plasma CA produced by TRH but not the potentiation of this hyperthermia by exogenous CA. 4 Hypophysectomy abolished the TRH-induced hyperthermia but not the increase of plasma CA or the potentiation of this hyperthermia by exogenous CA. 5These results suggest that, in mice, both the adrenal medulla and the pituitary gland play an essential role in TRH-induced hyperthermia but not in its potentiation.

Effects of intravenous thyrotropin-releasing hormone on 18F-fluorodeoxyglucose uptake in human brown adipose tissue: a randomized controlled trial

“…In the hypothalamus-pituitarythyroid axis, the cold-induced increase in TRH stimulates TSH secretion by the pituitary, which in turn stimulates thyroid hormone release from the thyroid (11). Research in various species showed that both core body temperature (32,33) and BAT-specific temperature (13) are increased by central or peripheral administration of TRH. Intracerebroventricular infusion of TRH in rodents was found to activate BAT via sympathetic neurons, an effect that could be blocked by pre-treatment with TRHreceptor type 1 antibodies and attenuated by sympathetic denervation of BAT depots (13,14).…”

Thyrotrophin‐Releasing Hormone Decreases Feeding and Increases Body Temperature, Activity and Oxygen Consumption in Siberian Hamsters

“…However, the observation that the lower dose of TRH (5 mg/kg) increased locomotor activity but had no significant effect on body temperature suggests that the mechanism involved in TRH‐induced thermogenesis is not simply via the induction of locomotor activity. In mice, it has been shown that peripheral injections of TRH at a dose of 40 mg/kg also induced a rapid and short‐lasting hyperthermia (47). In rats, central administration of TRH induces hyperthermia (22), and antagonises drug‐induced hypothermic effects (48).…”