Neurotransmitter regulation of arginine vasotocin release from rat pineal glands in vitro.

Studies were performed to determine the effects of neurotransmitters on arginine vasotocin (AVT) release in vitro. Rat pineal glands were incubated with 10(-8)M or 10(-6)M norepinephrine (NE), dopamine (DA), serotonin (5HT), and acetylcholine (ACH) for eight h after which the concentrations of AVT in the media were determined by radioimmunoassay. With the exception of ACH, none of the neurotransmitters had a significant effect on AVT release. ACH significantly (P less than 0.05) elevated AVT release in vitro at the 10(-6)M concentration but not at the 10(-8)M concentration. The data indicate that ACH may play a role in the regulation of rat pineal gland secretion of AVT in vitro.