Gonadotrophic control of steroidogenesis in XXXX granulosa-lutein cells.

@entity1 @entity251 @entity1420 @entity53 @entity342
Granulosa-lutein cells were harvested from periovulatory follicles in @entity1 ovaries and cultured for up to 6 days, equivalent to almost half of a normal luteal phase. The average rate of basal @entity1420 accumulation in the culture medium was constant at approximately 36 nmol @entity1420 /10(6) cells/day. @entity53 accumulation was too low to measure in the absence of precursor @entity342 . Basal aromatase activity (measured as @entity53 formed in 3 h from 10(-6) M exogenous @entity251 ) was high (average 1.15 nmol @entity53 /10(6) cells/3 h) at the time of cell isolation (Day 0) but fell by greater than 90% on Day 1. By Day 2 the activity had partly recovered and averaged 62% of the Day 0 value, rising to 70% on Day 6. This loss and recovery of aromatase activity was independent of the addition of gonadotrophic hormones to the culture medium. However, dose-related increases in aromatase activity occurred in the presence of highly pure @entity1 pituitary LH (0.1-30 ng/ml). The increase was observed on Day 4 and was maximal on Day 6 (average 3-fold increase over control) in the presence of LH concentrations greater than or equal to 1.0 ng/ml. LH also caused dose-related increases in @entity1420 accumulation by Day 4 with maximal stimulation on Day 6 (average 3-fold increase over control) at greater than or equal to 10.0 ng/ml. Dose-related stimulation of aromatase activity by @entity1 pituitary FSH also occurred but maximal stimulation required the presence of 300 ng FSH/ml and @entity1420 accumulation was hardly affected at this dose.(ABSTRACT TRUNCATED AT 250 WORDS)
