Medeiros Y S, Calixto J B
Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
Pharmacology. 1989;38(4):235-42. doi: 10.1159/000138542.
The influence of thyroid dysfunction on rat myometrial responsiveness to oxytocin, acetylcholine, CaCl2 and BaCl2 was assessed in uterine strips from pregnant and nonpregnant rats. In preparations obtained from hypothyroid nonpregnant rats, oxytocin and acetylcholine concentration-response curves were significantly displaced to the left, whereas myometrial strips from hyperthyroid nonpregnant rats were only supersensitive to acetylcholine. In relation to the pregnant state, T3 treatment caused an increased myometrial sensitivity to both oxytocin and acetylcholine. In this condition, concentration-response curves for oxytocin did not differ from nonpregnant control animals, whereas acetylcholine was about 300-fold more potent at the ED50 levels compared with those in nonpregnant animals. Either in pregnant or nonpregnant state, maximal responses and ED50 to BaCl2 did not differ. In addition, thyroid dysfunction did not modify the pattern of CaCl2-induced contractions in isolated myometrial strips from pregnant rats. This data extended to the myometrium, previous evidence in the literature indicating that thyroid dysfunction may affect uterine responsiveness to agonists.
在妊娠和非妊娠大鼠的子宫肌条中评估了甲状腺功能障碍对大鼠子宫肌层对催产素、乙酰胆碱、氯化钙和氯化钡反应性的影响。在甲状腺功能减退的非妊娠大鼠制备的标本中，催产素和乙酰胆碱浓度-反应曲线显著左移，而甲状腺功能亢进的非妊娠大鼠的子宫肌条仅对乙酰胆碱超敏。关于妊娠状态，T3治疗导致子宫肌层对催产素和乙酰胆碱的敏感性增加。在这种情况下，催产素的浓度-反应曲线与非妊娠对照动物无差异，而与非妊娠动物相比，乙酰胆碱在ED50水平时的效力约高300倍。无论在妊娠还是非妊娠状态下，对氯化钡的最大反应和ED50均无差异。此外，甲状腺功能障碍并未改变妊娠大鼠离体子宫肌条中氯化钙诱导的收缩模式。这些数据扩展到子宫肌层，文献中先前的证据表明甲状腺功能障碍可能影响子宫对激动剂的反应性。
