IN-VITRO CULTURE OF HAMSTER OVARIAN PRIMARY INTERSTITIAL-CELLS - EFFECT OF SERUM

The function of ovarian interstitial cells has been largely addressed using rat theca-interstitial cell culture. However, this preparation i s primarily enriched with theca and secondary interstitial cells, whic h make it difficult to address selectively the function of the primary interstitial cells. We have developed an in vitro culture of hamster ovarian primary interstitial cells. Cells were isolated from postnatal hamster ovaries by collagenase digestion and purified over a Percoll gradient. The preparation contained 90% viable, pure interstitial cell s, which anchored to the plastic and glass culture surface in the pres ence of fetal bovine serum. Cell proliferation was noted in the presen ce of serum dosages higher than 0.2%; however, reduction of serum conc entration to 0.1% or complete serum starvation did not affect cell via bility but almost completely abolished cell proliferation as determine d by [H-3]thymidine incorporation, labeling index, and DNA content of the culture. All cells exhibited active 3 beta-hydroxysteroid dehydrog enase and P450 side chain cleavage immunoreactivity, which corresponde d to basal progesterone and androstenedione accumulation. Replacement of serum to starving cells resulted in the induction of the ''S'' phas e and ''M'' phase specific cyclins, and resumption of cell proliferati on. Our results indicate that hamster primary interstitial cells can b e cultured in vitro as a monolayer, and the anchorage and proliferatio n of these cells depend on serum supplement; however, a viable monolay er can be maintained for several days without serum. This model will b e useful for addressing the mechanisms of differentiation of ovarian i nterstitial cells.