The effects of forskolin and LH on cAMP changes and maturation in the follicle-enclosed oocytes of hamsters.
Graafian follicles from mature pro-oestrous hamsters were incubated with LH, various concentrations of forskolin, or forskolin plus LH. The incubations were either terminated at different time periods for analysis of follicular or oocyte cAMP levels or incubated for the entire 6 h and the oocytes examined to determine maturational status. Incubations with LH (1 microgram/ml) produced a short transient rise in follicular and oocyte cAMP concentrations, while forskolin (60 microM, 20 microM and 10 microM) produced cAMP values which remained elevated for longer periods of time. The 1 microM concentration of forskolin initiated oocyte maturation (28%) but at a level which was significantly below that stimulated by LH (74%). When LH was included with forskolin, a dramatic rise in follicular cAMP occurred which was approximately 2 times greater than levels seen with LH alone. A significant percentage of oocytes matured when 100 nM forskolin (45%) was included with LH (1 microgram/ml) but not with any other concentration of forskolin tested. Maturation percentages for follicle-enclosed oocytes exposed to 1 microM forskolin plus 1 microgram/ml of LH (3.8%) were not different from the controls (7%). However, when 1 microM forskolin was combined with 100 ng/ml of LH a significant percentage of oocytes matured (47%). While continuous incubations with forskolin did not stimulate a high percentage of oocytes to mature, oocytes from follicles exposed to forskolin (60 microM and 20 microM) for short periods (5 min-30 min) with a change to plain medium did mature. The results of these studies indicate that, in the hamster, long term exposure to forskolin inhibits maturation in follicle-enclosed oocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology*; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism*; D005260:Female; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008647:Mesocricetus; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism
D005576:Colforsin; D007986:Luteinizing Hormone; D000242:Cyclic AMP