Low temperature in the golden hamster accelerates the gonadal atrophy induced by short photoperiod but does not affect the daily pattern of melatonin secretion.

Male golden hamsters were exposed to short photoperiod at either 20 degrees C or 5 degrees C. After 4 weeks a complete gonadal inhibition was observed in animals kept at 5 degrees C while in animals kept at 20 degrees C such an inhibition was much less. No significant difference in the pattern of pineal and plasma melatonin concentrations was observed between hamsters kept at 20 degrees C and 5 degrees C. If in the golden hamster pineal melatonin secretion is implicated in the transduction of the photoperiodic information, it is probably not implicated in the transduction of thermal information.