Autonomous progesterone secretion from the bovine corpus luteum in vitro

• DOI: 10.1530/acta.0.1240179
• Publication Date: 2009-06-11T17:28:10Z
• Authors: Winfried G. Rossm...; Markus Schick; Reiner Benz; Christian Lauritzen
• Keywords: EGTA

Abstract. While the regulation of progesterone secretion from corpus luteum by LH has been convincingly demonstrated, secretory patterns in absence any pituitary inputs are yet unclear. Consequently, we investigated an vitro perifusion system to characterize spontaneous release isolated bovine luteum. Slices (120 mg) midluteal corpora lutea were placed chambers and continuously perifused Medium-199 for 160-320 min. Progesterone was determined radioimmunoassay effluent fractions collected at 2-min intervals. The all pulsatile. Pulses observed mean (± sem ) intervals 17.7±1.5 min with amplitudes 6.7±0.5 ng rates 29.5±2.4 · ml −1 (2 min) (N=5). Addition 6.7 nmol/l hCG medium appeared increase pulse (195±25% over unstimulated conditions), but did not change frequencies (N=3). Perifusions calcium-free containing 50 μmol/l verapamil 20 mmol/l EGTA tended suppress this release, whereas addition reversed decrease again When prostaglandin activity inhibited 100 indomethacin added medium, both enhanced (N=4). During perifusions anti-progesterone ZK 96.734, increased These studies demonstrate episodic vitro. is independent of, facilitated gonadotropin secretion. This pulsatile its intraovarian factors may reflect autonomous generating mechanism.