title: A circannual rhythm in bovine pineal serotonin.
abstract: Bovine pineal serotonin (5-HT) was analyzed at the time of the solstices and equinoxes from December, 1975 until June, 1978. The highest values of 5-HT were detected at the winter solstices and lowest values at the summer solstices of each year examined. The peaks in bovine pineal 5-HT correspond with a lessened fertility in cattle reported during the winter months.
mesh_terms: D000818:Animals; D001683:Biological Clocks; D002417:Cattle; D005260:Female; D010870:Pineal Gland / Q000378:metabolism*; D012098:Reproduction; D012621:Seasons; D012701:Serotonin / Q000378:metabolism*
chemical_list: D012701:Serotonin