Calcium Ions in the Steroidogenic Action of HCG

1982 Folia Endocrinologica Japonica  
Extensive studies have recently been conducted on the expression of hormone actions, especially on its mechanisms. Sutherland, et al. identified the function of C-AMP as an intracellular messenger of peptide hormones. Recent studies by several investigators including ours have concluded that the role of C-GMP and calcium are as important as that of C-AMP. In this report we present our findings on the role of Ca ions in the acceleration of steroid production in isolated porcine cells of the
more » ... ra lutea. (1) The incubation time needed to compare the production of progesterone and that of C-AMP is at least 120 mins. (2) Production rates of both C-AMP and progesterone in the presence of HCG were maximum at 10-7g/m1 HCG. Inclusion of Ca ions in the medium increases this production rate. (3) When Ca ions are included in the medium, the accelerated rate of progesterone production takes on its highest value at 1.2mM Ca. (4) Verapamil and cycloheximide inhibit the production of progesterone. (5) The binding capacity of 125 I-HCG combined with corpora lutea cells is independent of the Ca concentration in the medium. (6) Ca uptake into corpora lutea cells increases according to the concentration of HCG until it reaches a plateau at 107g/m1 HCG.
doi:10.1507/endocrine1927.58.6_833 pmid:6288487 fatcat:seug6qndtjhplivyknhgedmpwe