Acute insulin stress increased plasma catecholamine levels in both the Syrian hamster and albino rat within 3 h after an intraperitoneal injection of either 5 or 10 units of insulin. In the rat, this stress caused a concurrent increase in pineal serotonin N-acetyltransferase (NAT) activity and melatonin content with no observable change in hydroxyindole-O-methyltransferase (HIOMT) activity. In the hamster, on the other hand, acute insulin stress did not alter pineal NAT activity, but depressed both HIOMT activity and melatonin content up to 3 h after the stress. These results present further evidence that catecholamines do not control hamster pineal melatonin synthesis by the same mechanism as observed in the rat. © 1985.
Champney, T. H., Steger, R. W., Christie, D. S., & Reiter, R. J. (1985). Alterations in components of the pineal melatonin synthetic pathway by acute insulin stress in the rat and Syrian hamster. Brain Research, 338(1), 25–32. https://doi.org/10.1016/0006-8993(85)90244-6