Altered Thermoregulatory Responses After 15 Days of Head-Down Tilt

摘要

To determine if extended exposure to simulated microgravity altersthermoregulatory reflex control of skin blood flow, six adult males were exposed to 15 days of 60 head-down tilt (HDT). On an ambulatory control day prior to HDT exposure, and on HDT day 15, internal temperature of each subject was increased 0.5 to 1.0 deg C with a water perfused suit. Skin temperature (Tsk), sublingual temperature (Tor), mean arterial pressure (MAP) and forearm blood flow (FBF) were measured throughout the protocol. Forearm vascular conductance (FVC) was calculated from the ratio of FBF to MAP. Following HDT exposure, the Tor threshold at which reflex thermally-induced increases in FVC began was elevated