The musculature of the Fallopian tube is hyperactive during the time of ovulation, but the mechanism which activates the tube is obscure. A humoral regulation of tubai motility is more probable than a nervous one, although it is not known to what extent biogenic compounds (tissue hormones) can stimulate the tubes.
We have investigated this question on a quantitative pharmacological basis using eighty-four human tubes on the day of removal. Strips were cut from the infundibular end and suspended in 10 ml Krebs-Henseleit solution at 32° C and aerated with carbogen. The contractions of the preparations were recorded isotonically on smoked paper. The experiments were designed to yield dose-response curves from which the EC50-values and other parameters mentioned in Table 1 were determined. Text-fig. 1 gives two typical examples of dose-dependent responses and shows not only that tubai strips in vitro produce powerful contractions, but also that there are great quantitative differences between the endecapeptide eledoisin, and acetylcholine. Noradrenaline and the peptides oxytocin, bradykinin, kallidin, and angiotensin were practically inactive. The active substances are summarized in Table 1. In contrast with the well-known biogenic amines acetylcholine, histamine, and