Influence of pregnancy, oophorectomy and contraceptive steroids on gall bladder concentrating function and hepatic bile flow in the cat.

Pregnancy and contraceptive steroids are associated with a raised incidence of cholesterol gall stone disease. In pregnancy there is an increase in the size of the gall bladder. Investigation of hepatobiliary function in man and mammals has not established if the enlarged gall bladder is simply dilated, or if the absorptive capacity of the mucosa has changed. In the present study the concentrating function of the gall bladder and bile secretion from the liver were studied in pregnant animals, oophorectomised animals and animals treated for three months with contraceptive steroids. The effects of intravenous administration of prolactin, progesterone and oestrogen were studied in oophorectomised animals. It was found that the net rate of water absorption in the gall bladder of pregnant animals was doubled, while oophorectomy and contraceptive steroids did not affect this variable. The volume outflow of bile was enhanced in pregnant animals and in animals treated with contraceptive steroids. Intravenous infusions of prolactin, oestrogen or progesterone were found not to influence gall bladder concentrating function, nor hepatic bile secretion in oophorectomised animals.