<prompt> The sensitivity of uterine musculature isEnhanced by progesteroneEnhanced by estrogenInhibited by estrogenEnhanced by estrogen and Inhibited by progesterone  <response>: 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. 