A COMPARATIVE STUDY OF PINEAL ACETYL‐CoA HYDROLASE AND N‐ACETYLTRANSFERASE ACTIVITIES

pineal acetyl‐CoA hydrolase is measurable at 4 days before birth. It increases rapidly to a maximum of 0.37 nmol/min/0.1 mg protein during the first week after birth, thereafter gradually decreasing and stabilizing at adult levels (0.27 nmol/min/0.1 mg protein) 3‐4 weeks after birth. Unlike A/‐acetyltransferase, the activity of acetyl‐CoA hydrolase does not increase following treatment with isoproterenol, does not exhibit a circadian rhythm and is not inactivated on exposure of the animals to light at night. In addition, denervation of the pineal gland does not alter acetyl‐CoA hydrolase activity.