Influence of fasting and dopamine on the tissue catecholamines diurnal variations

Abstract

2 figures)To define the role of catecholamines (CA) in the metabolic adaptation to fasting we examined the effect of exogenous dopamine(DA) on heat production(HP) and CA content in the interscapular brown adipose tissue(1BAT) and adrenals of controlfed and 2-day fasted rats in the morning(M) and in the evening(E).DA stimulates HP in fed rats in the M by 45% but the thermogenic effect of this CA is markedly higher in the E. However, DA had no thermogenic effect in fasted rats. The tissue CA in fed rats fluctuates diurnally : in the IBAT noradrenaline(NA) was much higher in the E while adrenaline(A) in adrenals was lower. DA in fed rats did not change the adrenal A but reduced NA content both in the adrenals and in the IBAT all over the day. Fasting depleted A from adrenals but increased NA content both in the M and in the E. Unlike the adrenals in the IBAT fasting did not affect NA content. In the adrenal gland of fasted rats DA significantly increased the A content to the equal degree during the day, while this CA had no effect on NA content of the IBAT. Archives of Physiology and Biochemistry Downloaded from informahealthcare.com by McMaster University on 12/27/14 For personal use only. VUKOSAVA DAVIDOVIC Institute of Physiology and Biochemistry, Faculty of Sciences, University of Belgrade Studentski trg 16, P. 0. Box 550, 11OOO Beograd, Yugoslavia. Archives of Physiology and Biochemistry Downloaded from informahealthcare.com by McMaster University on 12/27/14 For personal use only.

Dopamine directly increases mitochondrial mass and thermogenesis in brown adipocytes

“…Diet-induced thermogenesis also increases DA release from sympathetic nerves to BAT in rats (Rothwell et al 1982). In line with these findings, exogenous DA causes a rise of heat production in rats (Davidovic et al 1988).…”