Oxytocin stimulates uterine prostaglandin F2 alpha secretion in red deer Cervus elaphus

The prostaglandin F2 alpha analogue cloprostenol stimulates ovarian secretion of oxytocin in red deer hinds and Père David's deer hinds, as in cattle and sheep, but the response of the uterus to administered oxytocin has not been studied in deer. In the present experiment, oxytocin administered intravenously caused an increase in circulating concentrations of 13,14-dihydro-15-keto prostaglandin F2 alpha from 186 +/- 35 to 404 +/- 34 pmol L-1 within 5 min; concentrations in saline-treated hinds were unchanged (150 +/- 12 and 164 +/- 12 pmol L-1 before and after treatment respectively). This suggest that in red deer as in other ruminants, a positive feedback relationship between the corpus luteum and the uterus may operate to stimulate luteolytic episodes of prostaglandin F2 alpha.