Effects of cyclic AMP and phorbol ester on transepithelial electrical resistance of Sertoli cell monolayers in two-compartment culture.
The effects of dibutyryl cyclic AMP [Bu)2cAMP) and phorbol ester (TPA), in the absence or presence of follicle-stimulating hormone (FSH) and/or testosterone, on the development of tight junctions by immature rat Sertoli cells (Sc) were investigated in vitro using the two-compartment culture system. The tight junction status was evaluated by repeated measurements of transepithelial electrical resistance (TER). Untreated cell monolayers developed stable TER of approximately 120 omega cm2 during 3 days of culture. Continuous presence of FSH (200 ng/ml) from day 1 onward significantly increased the TER up to approximately 300 omega cm2 after a transient (24-36 h) delay. The initial delay was prolonged to 3-4 days by the addition of 1-methyl-3-isobutylxanthine (MIX) (0.2 mM), whereas the subsequent increase of TER was significantly potentiated by the concomitant presence of testosterone (10 microM). Cholera toxin (CHT; 10 ng/ml) and forskolin (FR; 50 microM) mimicked these FSH effects. (Bu)2cAMP, at concentrations which maximally stimulated immunoactive inhibin secretion (100-500 microM), inhibited the initial TER increase and significantly decreased the TER level when added on days 1 and 5 of culture, respectively. In contrast, low concentrations of (Bu)2cAMP (4-20 microM) consistently stimulated the TER development, mimicking the stimulatory phase of FSH action. TPA (100 nM) alone had no effect on TER development, but potentiated the stimulatory effect of testosterone in a manner similar to FSH, CHT, FR or low concentrations of (Bu)2cAMP. These results demonstrate, for the first time, a concentration-dependent, dual effect of exogenous cAMP on the Sc function.(ABSTRACT TRUNCATED AT 250 WORDS)
Janecki
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Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Medical School, Houston 77030.
Jakubowiak
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Steinberger
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D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D004553:Electric Conductivity; D004848:Epithelium / Q000502:physiology; D005640:Follicle Stimulating Hormone / Q000502:physiology; D007365:Intercellular Junctions / Q000502:physiology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D015290:Second Messenger Systems / Q000502:physiology*; D012708:Sertoli Cells / Q000166:cytology* / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D005576:Colforsin; D003994:Bucladesine; D005640:Follicle Stimulating Hormone; D002772:Cholera Toxin; D000242:Cyclic AMP; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine