Changes in Responsiveness of Porcine Granulosa Cells to Prostaglandins and Luteinizing Hormone in Terms of Cyclic-AMP Accumulation During Follicular Maturation

Abstract

Kolena and Channing (1) have shown previously that: 1.) luteinizing hormone (LH) and prostaglandin E₂ (PgE₂) can stimulate cyclic-AMP accumulation by granulosa cells from medium-sized porcine follicles and 2.) the effects of these substances when mixed together were more than additive. Such a finding suggests but does not prove they acted at different receptor sites. Channing (2) and Lindsey and Channing (3) have found that granulosa cells obtained from small (1–2 mm) porcine follicles responded minimally to LH while cells harvested from medium and large follicles were more responsive to LH. Cells from large follicles produced 6–15 fold more cyclic-AMP in comparison to controls when stimulated by LH, while cells from small follicles exhibited not more than a three-fold increase in cyclic-AMP accumulation in response to LH. If it is true that prostaglandins of the E and F series have separate receptor and/or adenyl cyclase systems compared to LH, then it would be expected that changes in responsiveness of porcine granulosa cells obtained from different sized follicles to prostaglandins would be different compared to LH.