THE REACTIONS OF THE HUMAN FOETAL GASTROINTESTINAL TRACT IN VITRO

¹ From the Nuffield Institute for Medical Research and the University Department of Pharmacology, Oxford

1. The gastro-intestinal tracts of four human foetuses aged 8, 11, 15 and 16 weeks have been investigated in vitro by an optical recording apparatus.

2. Rhythmic contractions were observed in a circular ring from the stomach of an 8 weeks foetus, in which the longitudinal muscle layer had not yet appeared. Rhythmicity was seen in all cases in which the long axes of the muscle fibres (as found histologically) corresponded with the direction of suspension of the tissue.

3. The intestine of the younger foetuses required a longer immersion in warm oxygenated Locke's solution than that of the older ones before contractions began. This suggested that the ability to perform intestinal movements was latent in the younger foetuses.

4. The excised intestine of the younger foetuses lost its power to become rhythmical and to react to drugs before that of the older ones.

5. In the small series examined the bowel was sensitive to acetylcholine at an earlier age than to adrenaline.