Blood Flow and Peripheral Catecholamine Release during Localized Hand Cooling.

摘要

A unilateral cold hand immersion challenge was used to identify circulating catecholamine differences between immersed and non-immersed arms. There were no significant differences in either plasma norepinephrine or epinephrine concentration between arms. Plasma epinephrine was unaffected by the cold hand immersion challenge, whereas plasma norepinephrine values increased appreciably. Upon rewarming, plasma norepinephrine peaked within two minutes in the non-immersed hand, while it peaked later (approximately five minutes) in the immersed hand. In a second experiment, fingertip capillary perfusion decreased upon immersion in cold water for both hands. However, the non-immersed fingertip capillary perfusion immediately began to return towards basal levels. The immersed hand demonstrated continued reductions for as long as 20 minutes after removal from the cold water stimulus. And last, no gender related differences in circulating plasma catecholamines at rest or after the cold hand immersion challenge were noted. Keywords: Pressor test; Catecholamines; Capillary perfusion. (KT)