Alterations in hypothalamic serotonin metabolism in male hamsters with photoperiod-induced testicular regression.
Transfer of adult male golden hamsters to a short photoperiod (SD; 8L:16D) resulted in a significant decrease in testicular weight and plasma luteinizing hormone (LH) and prolactin (Prl) levels as compared to animals maintained in a long photoperiod (LD; 16L:8D). These changes were accompanied by significant increases in serotonin (5-HT) synthesis in the medial basal hypothalamus (MBH) as determined by measuring 5-hydroxytryptophan accumulation after inhibition of aromatic amino acid decarboxylase with NSD-1015. Serotonin synthesis in the median eminence, anterior hypothalamus and olfactory bulbs was not different in SD vs LD animals. Transfer of SD gonadally regressed hamsters to LD restored MBH 5-HT synthesis to control levels.
Steger
R W
RW
Department of Physiology, Southern Illinois University School of Medicine, Carbondale 62901.
Dennis
C
C
VanAbbema
A
A
Gay-Primel
E
E
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D006224:Cricetinae / Q000502:physiology*; D007031:Hypothalamus / Q000378:metabolism* / Q000502:physiology; D008297:Male; D008647:Mesocricetus / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism*; D013737:Testis / Q000502:physiology*
D012701:Serotonin