Estrogenic effects of phenol red on rat pituitary cell responsiveness to gonadotropin-releasing hormone.
This study investigated whether phenolsulfonphthalein (PR), a common pH indicator in tissue culture media, affects luteinizing hormone (LH) secretion from rat pituitary cells or 17 beta-estradiol (E2) augmentation of pituitary responsiveness to gonadotropin-releasing hormone (GnRH). PR enhanced GnRH-stimulated LH secretion and shifted the GnRH dose-response curve leftward with a relative potency ratio of 0.24 +/- 0.09 (+/- SE; p less than 0.01). The effect of E2 on LH release was significantly diminished by PR, which elevated GnRH-stimulated LH secretion in the absence of E2. This phenomenon was elicited by PR from different sources and was inhibited by the antiestrogen Cl628. Thus, PR exerted estrogen-like effects on rat pituitary cells and caused an underestimation of the degree to which E2 enhanced GnRH-stimulated LH secretion.
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Department of Obstetrics and Gynecology, University of Wisconsin Medical School, Madison 53792.
Renk
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Kamel
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D000818:Animals; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005188:False Negative Reactions; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000378:metabolism*; D009594:Nitromifene / Q000494:pharmacology; D010635:Phenolphthaleins / Q000494:pharmacology*; D010637:Phenolsulfonphthalein / Q000494:pharmacology*; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D010635:Phenolphthaleins; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D009594:Nitromifene; D007986:Luteinizing Hormone; D010637:Phenolsulfonphthalein