Interruption of nocturnal pineal melatonin synthesis in spontaneous recrudescent Djungarian hamsters (Phodopus sungorus).


The duration of nighttime synthesis of the pineal hormone melatonin is believed to determine the breeding season in many mammalian species. Hamsters exposed to short days undergo gonadal involution followed by a return to normal function, suggesting a developed insensitivity to regressive photoperiods. This recrudescence may be due to either exhaustion of… (More)