STUDIES ON THE UTERUS

Abstract

VI. In experiments [apparently on 10 rabbits] a difference in threshold of the uterus to the action of Theelin on uterine motility was found in the first few days of pseudopregnancy. The initial cessation of motility may be overcome with small amounts of Theelin. After 4 days this was impossible with large amounts, whether given subcutaneously, intravenously, or by both methods over a period of 2-4 days. An acceleration in the return to activity following pseudo-pregnancy was not possible with the amounts employed. The effect of oestrin apparently is definitely inhibited after the first few days of pseudopregnancy, as regards its action on uterine motility. VIII. The uterine fistula preparation affords an adequate means whereby anaphylactic shock may be recorded in the unanesthetized rabbit. In 11 rabbits sensitized after parturition the normal type of uterine activity was retained, and the uterus responded with a marked tetanus in anaphylactic shock; 6 rabbits sensitized in early pregnancy did not show normal post-partum uterine activity. The data suggest that sensitization during early pregnancy is not easily accomplished. A marked difference exists in the latent period of the uterine response to pituitrin and to the shock dose of serum in the sensitized animal.