title: Estrogen modulation of uterine adrenergic-cholinergic interaction: effects on vasoactivity and adrenergic receptors in the guinea pig.
abstract: The regulation of uterine blood flow (UBF) in the guinea pig was investigated by determining the effects of steroid-catecholamine interaction on guinea pig UBF in cyclic (Day 0 = estrus) and ovariectomized (OVX)-steroid treated females. In cyclic guinea pigs, parallel elevations in uterine weight, UBF, beta and alpha receptor levels were observed during the estrus period, whereas uterine norepinephrine (NE) levels were low. In contrast, all parameters remained at low levels except NE levels during the luteal phase of the cycle which remained elevated in both normal and OVX-oil treated animals. Estrogen (E1)-treated females showed elevated uterine weights, UBF, beta, and alpha receptor levels but low uterine NE concentrations. Combined progesterone-estrogen (P2E1) treatment caused similar changes but maintained tissue NE at control levels. In the exposed uterine artery preparation, the sequential administration of acetylcholine followed by NE application induced a marked elevation in UBF in OVX, E-1-treated animals which was blocked by phentolamine (10(-6) M). This phenomena could not be demonstrated in either oil- or progesterone-treated OVX guinea pigs. In uterine membrane preparations from ovariectomized guinea pigs pretreated with either oil or progesterone, methacholine (cholinergic agonist; 10(-6) M) failed to alter the affinity of the alpha receptor for NE. However, in uterine preparations from OVX, estradiol-treated guinea pigs, methacholine significantly (P less than .05) increased the affinity of the alpha receptor for NE.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D004971:Estrus; D005260:Female; D006168:Guinea Pigs; D016210:Methacholine Chloride; D008688:Methacholine Compounds / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism* / Q000494:pharmacology; D010052:Ovariectomy; D010053:Ovary / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011950:Receptors, Cholinergic / Q000378:metabolism*; D012039:Regional Blood Flow / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology; D013256:Steroids / Q000494:pharmacology; D014599:Uterus / Q000098:blood supply*
chemical_list: D004967:Estrogens; D008688:Methacholine Compounds; D011941:Receptors, Adrenergic; D011950:Receptors, Cholinergic; D013256:Steroids; D016210:Methacholine Chloride; D012701:Serotonin; D011374:Progesterone; D004958:Estradiol; D000109:Acetylcholine; D009638:Norepinephrine