COMPARISON OF BETA-1-RECEPTOR AND BETA-2-RECEPTOR STIMULATION IN ESTROGEN OR PROGESTERONE DOMINATED RAT UTERUS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 47  (4) , 252-258
Abstract
Electrical stimulation of rat uterine preparations induced constant and reproducible contractions. The inhibitory effect of some adrenergic substances was tested on estrogen- or progesterone-primed electrically stimulated rat uteri. The rank order of the relative potencies of some adrenergic agonists was shifted from Iso [isoprenaline] > E [epinephrine] > Salb [salbutamol] > Ne [norepinephrine] > H 133/22 [1,4-hydroxyphenoxyl-3-isopropylamine-2-propanol] > Phe [phenylephrine] > Clo [clonidine] in the estrogen primed uterus to Iso > Salb > E > Ne > Phe > Clo > H 133/22 in progesterone primed uterus. The selective .beta.2-agonist salbutamol was relatively more potent in progesterone treated rats than in estrogen treated, while the .beta.-agonist H 133/22 was more potent in estrogen dominated uterus. .beta.2-Receptors may dominate in the progesterone primed uterus, while both .beta.1 and .beta.2-receptors were found in estrogen primed uterus. No dissociation between the inhibitory effect on contractility and the cAMP increasing effect of Iso was demonstrated in rat uteri.