Abstract
Measurements of histamine in control and IUCD-containing uterine horns of the rat in di-estrusand L4 [L. designates the day spermatozoa were found in the vaginal smear] of pregnancy showed that device-containing horns the histamine content on L4 was the same as the di-estrous value. These data are interpreted in terms of a chronic inflammatory response in the IUCD-containing horn.