TY  - JOUR
AU  - Eldershaw TP, Duchamp C.
PY  - 1997//
TI  - Potential for nonshivering thermogenesis in perfused chicken (Gallus domesticus) muscle.
T2  - Comp. Biochem. Physiol., Part A Mol. Integr. Physiol.
JO  - Comparative biochemistry and physiology a-molecular & integrative physiology
SP  - 545
EP  - 554
VL  - 117A
IS  - 4
N2  - The humoral modulation of resting muscle heat production of chickens (Gallusdomesticus) was investigated in vitro. The resting distal lower limb was perfusedvia the popliteal artery at 25 degrees C without erythrocytes at constant flow.The preparation was stable for at least 3 hr, showing a constant oxygen uptake(MO2) and perfusion pressure as well as adequately maintaining muscle energycharge and creatine phosphate: creatine ratio. Noradrenaline (NOR), adrenaline(ADR) and serotonin (5-HT) each caused a dose-dependent rise in perfusionpressure. NOR and ADR evoked increased MO2 at low doses eventually followed bydecreased MO2 at higher agonist concentrations. 5-HT gave smaller butqualitatively similar MO2 effects. The actions of 50 nM NOR were blocked byprazosin (10 microM) and nitroprusside (0.5 mM), but not altered by propranolol(10 microM). NOR-induced stimulatory MO2 changes in the presence ofpharmacological concentrations (1 microM) of glucagon were more pronounced andthe thermogenic concentration range of NOR was increased. Taken together, thesein vitro findings demonstrate a potential for vasoconstrictor-controlled musclenonshivering thermogenesis in birds as in marsupials and mammals, suggesting thatvascular control of muscle MO2 may be a widespread biological mechanism. Thepossible implications of these findings for avian nonshivering thermogenesis are discussed.
SN  - 1095-6433
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=1812), last updated on Tue, 21 Apr 2009 11:29:01 +0200
ID  - EldershawTP1997
ER  -