Organ blood flow and brown adipose tissue oxygen consumption during noradrenaline-induced nonshivering thermogenesis in the Djungarian hamster.
During NA-induced NST blood flow through BAT increased from 0.18 ml min-1 to 3.21 ml min-1 in 23 degrees C acclimated (equals thermoneutrality) and from 0.61 ml min-1 to 9.67 ml min-1 in outdoors (-2 to 12 degrees C Ta) acclimated Djungarian hamsters. In 23 degrees C acclimated hamsters this increase was accomplished by a diversion of blood flow from visceral organs without a change in cardiac output (19.7 versus 20.5 ml min-1 before and after NA). In outdoors acclimated hamsters we also observed a redistribution of blood flow from the viscera to BAT. In addition, cardiac output increased from 24.3 to 38.8 ml min-1. Metabolic rate of BAT in situ was determined from organ blood flow and the (A-V)O2 of blood across the interscapular BAT. BAT of outdoor acclimated hamsters showed a significantly higher metabolism in comparison to 23 degrees C acclimated hamsters (81.1 versus 30.4 mlO2h-1). Furthermore, this calculation revealed that 28% (23 degrees C acclimated hamsters) and 61% (outdoors acclimated hamsters) of total NST were located in BAT of Phodopus sungorus.
D000064:Acclimatization; D002001:Adipose Tissue, Brown / Q000098:blood supply / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001775:Blood Circulation / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects*; D006224:Cricetinae; D009638:Norepinephrine / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*
D009638:Norepinephrine