Gender influences the core temperature response to a simulated open field in adult guinea pigs

The induction of psychological stress is often accompanied by a transient i ncrease in core temperature, commonly referred to as stress induced hyperth ermia. Although stress-induced hyperthermia occurs when rats, mice, and pig s are exposed to a novel stimulus (e.g., a simulated open field, restraint, etc.), whether or not it occurs in guinea pigs has not been investigated. The present experiments were therefore carried out to investigate the therm oregulatory responses of both male (n = 7) and female (n = 7) adult guinea pigs when they were exposed to a simulated open field. Unexpectedly, neithe r the male nor female guinea pigs developed stress-induced hyperthermia. To the contrary, female but not male guinea pigs significantly decreased thei r core temperature during an open field experiment. The mechanism of the ge nder-specific thermoregulatory response of the adult guinea pig to psycholo gical stress is presently unknown. (C) 1999 Elsevier Science Inc.