“3H Progesterone specific binding of steroid hormone treated oviducal culture cells”,

PERALTA L.; ROLDÁN M.; SUAREZ A. Y MICELI D. C..

Tafi del Valle, Tucuman Argentina

Jornada; XVI Jornadas Científicas de la Sociedad de Biología de Tucumán.; 1999

Sociedad de Biología de Tucumán

3H PROGESTERONE SPECIFIC BINDING OF STEROID HORMONE TREATED OVIDUCAL CULTURE CELLS L. Peralta. M. Roldán. A.Suarez* and D. Miceli. I Dep.Biol. del Desarrollo. INSIBIO INST. de Biología. Chacabuco 461. *Inst. de Microbiología. Fac. de Bioq. Qca y Farm. Univ. Nac. de Tuc. Ayacucho 471. (4000) Tucumán. The experiments were carried out with pig oviductal cells depleted of progesterone binding sites. One lot of cells was used as control. A second one was induced with 1 mM progesterone (P 4). A third was treated with 16.7 nM 17 b-Estradiol (E2) and the fourth with a mixture of P 4 and E2 at the concentrations mentioned above. The binding incubation was carried out for 20 hours at 38.5°C under 5% CO2 atmosphere. Specific binding was determined by the differences between the radioactivity bound to the cell incubated only with 3H Progesterone and that bound in the presence of an excess of unlabeled P 4. After 45 min of incubation at 4°C. the cells were broken by a thermic shock (Iiquid N2 -37°C) and then filtered. The radioactivity present in the cell membrane retained by the filters, was determined. The cell under P 4 or E2 stimulation shows specific binding properties. However the induction capability of P 4 was at least twice highs as compared to E2. Strikingly, P 4 and E2 together showed a reciprocal inhibitory effect.