Cutaneous Blood Flow and Local Sweating after Systemic Atropine Administration,

摘要

Localized cutaneous vasodilation (flush) is seen following systematic atropine administration. To verify calculated enhanced dry heat loss with actual changes in cutaneous blood flow, four men were studied in both control and atropine experiments during moderate exercise. Esophageal temperature (Tes) and arm sweating (ms) by local dewpoint were measured continuously. Skin (forearm) blood flow (FBF) was measured twice each minute by venous occlusion plethysmography. Injection of atropine (2 mg) caused an increased sensitivity in FBF to Tes with no change in the vasodilator threshold. An elevated Tes onset for sweating occurred with no change in the sensitivity of ms to Tes. No elevation in either forearm occurred before the onset of vasodilation, however, both mean skin and local arm temperatures were higher in the atropine experiments after 15 min of exercise. Systematic atropine resulted in higher cutaneous vasodilation at the same core temperature with the local skin temperature following passively. The effect of systematic atropine in stimulation of increased cutaneous vasodilation is suggested to result by a combination of central and local responses which may be mediated through the release of vasoactive substances.