The levels of 11-deoxy-13,14-dihydro-15-keto-11 beta, 16 xi-cyclo PGE2 (bicyclo PGEM), 13,14-dihydro-15-keto PGF 2 alpha (PGFM), cortisol and prolactin were measured by radioimmunoassays in five serial plasma samples collected from fourteen patients undergoing falope ring application and three patients undergoing tubal electrocautery. Bicyclo PGEM, PGFM and cortisol levels were unchanged regardless of the type of tubal occlusion procedure or the type of anesthesia administered (7 received general and 10 local anesthesia). Prolactin levels, on the other hand, markedly increased. The increase was greatest in women that received general anesthesia. The lack of change in bicyclo PGEM and PGFM in peripheral plasma would suggest a local transfer of PGs produced by injured tubal tissue to other parts of the tube and the uterus resulting in increased contractions and pelvic pain.