1. To determine if exogenously administered α-melanocyte stimulating hormone (α-MSH) affects nighttime pineal N-acetyltransferase activity, pineal levels of 5-hydroxytryptophan, serotonin and melatonin, and plasma prolactin levels, adult male hamsters were injected at 1900hr (lights out 2000-0600 hr) with two doses of the peptide and killed at 0300 hr. 2. The low dose of α-MSH (200 ng) produced a significant fall in pineal serotonin, pineal NAT activity and plasma prolactin values. 3. The high dose of the peptide (20 μg) increased circulating prolactin titers and pineal serotonin levels and caused a concomitant decrease in pineal melatonin levels.
|Original language||English (US)|
|Number of pages||4|
|Journal||Comparative Biochemistry and Physiology. Part C, Comparative|
|State||Published - 1987|
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