The sensitivity of uterine musculature is: (A) Enhanced by progesterone, (B) Enhanced by estrogen, (C) Inhibited by estrogen, (D) Enhanced by estrogen and Inhibited by progesterone
Answer is D. Progesterone reduces muscle excitability by increasing calcium binding, thereby reducing free intracellular calcium. Oestrogen has the opposite effect and increases myometrial excitability.Refer page no 106 of Textbook of obstetrics, Sheila Balakrishnan, 2 nd edition.