Effect of angiotensin II on human luteinized granulosa cells

Abstract

To determine if human luteinized granulosa cells (GCs) exhibit angiotensin II (AII) receptors and if AII affects GC steroidogenesis. Luteinized GCs were either treated immediately or maintained in culture for up to 6 days before use. The presence of functional AII receptors was evaluated using the following criteria: [1] receptor binding of 125I-labeled AII; [2] changes in inositol phosphate production; [3] effects on progesterone (P) production; and [4] effects on cyclic adenosine 3':5' monophosphate (cAMP) production. No specific binding of 125I-labeled AII was observed using human luteinized GCs in culture. Angiotensin II did not alter the formation of [3H] inositol phosphates, nor did it alter the release of P from freshly isolated cells or cells that had been in culture for 5 days. Angiotensin II was also unable to alter basal or gonadotropin-stimulated cAMP production. These data suggest that human luteinized GCs exhibit little or no type 1 or type 2 AII receptors. This observation is in contrast to reports in rat granulosa that exhibit AII receptors. The reason for a lack of AII receptor expression on human luteinized GCs is unknown but could be because of luteal phase down regulation with gonadotropin-releasing hormone agonist or the subsequent stimulation with gonadotropins in these women before follicular stimulation.