Progesterone production by dispersed monkey (Macaca mulatta) luteal cells after exposure to trypsin

In an attempt to justify use of trypsin to achieve more thorough dispersion of luteal cell clumps in vitro, progesterone (P) production by collagenase dispersed monkey luteal cells from the mid-luteal phase corpus luteum (CL) was examined in vitro either after 10 min, or continuous (3h) exposure to trypsin (TR). In the first experiment, cells were pre-incubated in TR, then incubated at 37 degrees C for 3h with human chorionic gonadotropin (hCG) after the addition of soybean-trypsin inhibitor (STI). Pre-incubation of luteal cells with TR had no effect on the level of P production under basal conditions. Cells that were preincubated with TR responded to hCG stimulation with increased progesterone secretion (P less than 0.01) in a fashion similar to untreated cells. P production in response to hCG was independent of TR concentration over the range of 0.05% to 0.2% during the pre-incubation period. However, continuous exposure (3h) of cells to TR significantly depressed (P less than 0.01) basal P secretion and inhibited the response to hCG. We conclude that TR had no effect on the biopotency of hCG per se, but probably the over-exposure to TR had an adverse effect on the LH/hCG receptors. Addition of STI after a 10 min pre-incubation with TR, prevented these deliterious effects, thereby permitting the use of TR to improve the completeness of luteal cell dissociation.