Chemical sympathectomy and diurnal fluctuations of noradrenaline calorigenic action in the rat.
In the rat, in which a diurnal fluctuation of the sensitivity to noradrenaline was previously found, the effect of injected 6-hydroxydopamine (6-OHDA) was investigated. The heat production and catecholamines contents in the interscapular brown adipose tissue, heart and adrenals were measured. Chemical sympathectomy induces a disappearance of diurnal fluctuation in the sensitivity to injected noradrenaline. In these animals a lower capacity for heat production was found. However, a significant calorigenic effect of injected noradrenaline in 6-OHDA-treated animals was still present. In sympathectomized animals a depletion of noradrenaline from interscapular brown adipose tissue and the heart was observed. Besides, a change in adrenaline/noradrenaline ratio was found in the adrenals.
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D002395:Catecholamines / Q000378:metabolism; D002940:Circadian Rhythm / Q000187:drug effects*; D006358:Hot Temperature; D006892:Hydroxydopamines / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D013564:Sympathetic Nervous System / Q000187:drug effects*
D002395:Catecholamines; D006892:Hydroxydopamines; D009638:Norepinephrine