Relationship between modulation by estradiol, progesterone and calcium upon the pharmacological reactivity of uteri of dogs.
The influence of treatment with estradiol and progesterone, was studied on the contractions induced in immature dog uteri by histamine, acetylcholine, oxytocin and barium chloride, in vitro. Two parameters were measured from dose-response curves: rho and pD2. It was observed that although pD2 values were slightly affected by hormonal treatment, the values of rho for oxytocin and acetylcholine receptors were greatly reduced by estradiol treatment and further decreased by association of estradiol plus progesterone; the effects for histamine and barium chloride were less affected. Increasing Ca2+ concentration in the nutrient solution completely reverted the variations for rho values. The results indicate tat the effect of drugs on the dog uterus depends on the balance between the modulating actions of ovarian hormones and calcium.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D004285:Dogs; D004347:Drug Interactions; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D010121:Oxytocin / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology*; D014590:Uterine Contraction / Q000187:drug effects*
D001464:Barium; D011374:Progesterone; D004958:Estradiol; D010121:Oxytocin; D006632:Histamine; D000109:Acetylcholine; D002118:Calcium