title: A hormone from the uterus of the tsetse fly, Glossina morsitans, stimulates parturition and abortion.
abstract: Unlike most insects, the tsetse female gives birth to a single, fully grown larva at the culmination of each pregnancy cycle. The expulsion of the larva is regulated by a hormone present in rich abundance within the female's uterus. The hormone elicits parturition when injected into neck-ligated females at late stages of pregnancy and abortion when injected at earlier stages. We refer to this highly active material (0.043 uterus equivalents stimulates parturition in 50% of the females) as parturition hormone. Injection of the active extract, which appears to be a peptide or small protein, initiates the series of blood pressure pulsations and uterine contractions normally associated with parturition. The discovery that a uterus extract from the flesh fly also elicits parturition in tsetse suggests that this hormone may be widely distributed in insects.
authors.affiliation: International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
authors.forename: J
authors.initials: J
authors.lastname: Zdárek
authors.forename: D L.
authors.initials: DL
authors.lastname: Denlinger