Adult male hamsters were sacrificed in groups at 4 hour intervals over a 24 hour period. In one Experiment adult male Sprague-Dawley rats were also sacrificed. No statistically significant daily changes in noradrenaline (NA) content were observed in the hamster pineal in three separate experiments. On the other hand, a very significant daily change in NA content was observed in the rat pineal. Bilateral superior cervical ganglionectomy depleted NA in the hamster pineal. Marked daily changes in pineal NA may be peculiar to the rat. © 1976.
Morgan, W. W., Reiter, R. J., & Pfeil, K. A. (1976). Hamster pineal noradrenaline: Levels over a regulated lighting period and the influence of superior cervical ganglionectomy. Life Sciences, 19(3), 437–440. https://doi.org/10.1016/0024-3205(76)90051-5