Effects of some low molecular weight sheep pineal fractions and melatonin on different tumors in rats and mice.

With these preliminary experiments attention is drawn to a possible relation between tumor development and the pineal. The influence of melatonin and some low molecular weight pineal fractions on the growth and incidence of different experimental tumors was compared. Some pineal fractions which have an effect on the activity of hypothalamus on anterior hypophyses of male rats and mice in vitro may be active in some of these tumor models.