Repeated nitrous oxide exposure in rats causes a thermoregulatory sign-reversal with concurrent activation of opposing thermoregulatory effectors.

ABSTRACT: Initial administration of 60% nitrous oxide (N₂O) to rats at an ambient temperature of 21°C decreases core temperature (Tc), primarily via increased heat loss (HL). Over repeated N₂O administrations, rats first develop tolerance to this hypothermia and subsequently exhibit hyperthermia (a sign-reversal) due primarily to progressive increases in heat production (HP). When rats initially receive 60% N₂O in a thermal gradient, they become hypothermic while selecting cooler ambient temperatures that facilitate HL. This study investigated whether rats repeatedly administered 60% N₂O in a thermal gradient would use the gradient to behaviorally facilitate, or oppose, the development of chronic tolerance and a hyperthermic sign-reversal. Male Long-Evans

SUBMITTER: Ramsay DS 

PROVIDER: S-EPMC4414259 | biostudies-literature | 2014 Oct-Dec

REPOSITORIES: biostudies-literature