Abstract
As far as we are aware, antiperistalsis of the descending colon of rabbit has never been studied by direct inspection, yet this can be readily accomplished. The rabbit is narcotized by the subcutaneous injection of 150 mg sodium barbital per kilo; after 45 minutes the descending colon is exposed by a cut through the linea alba from the ensiform cartilage to the pubis; a segment of the descending colon is selected and prepared by making two cuts about 9 cm apart; these cuts sever 60% to 80% of the gut, opposite to the mesenteric border; the segment and adjacent portions of the colon are milked clear of scybala. Now by introducing dry, normal scybala either at the oral or aboral cut, peristaltic and antiperistaltic waves may be produced. Sluggish motor activity is readily improved by subcutaneous injection of 0.1 to 0.3 mg of physostigmine sulfate per kilo.
Results. The introduction of a dry scyba-lum 1 to 2 cm into the segment at the oral or aboral end generally produces a peristaltic contraction after a short period of time. If the progress of the scybalum is prevented by a gentle digital compression of the segment, the peristaltic wave of contraction sooner or later relaxes and the formerly relaxed, compressed area contracts, the scybalum now moves antiperistaltically and may be expelled at the oral cut or enter the colon oral to the cut.
The antiperistaltic wave shows the following characteristics:
1. A contraction wave of the circularis 0.5 to 1 cm long, produces a grayish-white bloodless cord, while its surface longitudinal layer appears pink. The length of the progressing contraction remains more or less constant. The contraction wave passes without noticeable pause through the cut to the oral colon.
Get full access to this article
View all access options for this article.