Effects of exogenous oestrogen and experimentally induced endometritis on absorption of sodium benzylpenicillin from the cow's uterus

Abstract

The effects of oestradiol benzoate or of experimentally induced infection on the absorption of sodium benzylpenicillin from the uterus were investigated in three groups of clinically normal, non-pregnant, Friesian cows. All were at day 12 following the day of oestrus. Oestradiol benzoate in oil was administered either into the uterus or intramuscularly one hour before the infusion of 22,000 iu/kg of sodium benzylpenicillin. The dose of oestradiol benzoate was 10 mg, apart from one cow in each group which received 25 mg. Inflammation was induced by infusing a suspension of Corynebacterium pyogenes in Ringer's solution into the uterus, 11 to 18 hours before penicillin infusion. The degree of absorption of penicillin was greater in all three groups than that previously determined in cows given penicillin alone at the same stage of the cycle. The results indicate that factors which might affect blood flow to the uterus may also influence the absorption of sodium benzylpenicillin from the uterus.