The measurement of colonic mucosal‐submucosal blood flow in man.

Abstract

A method is described for the measurement of colonic mucosal-submucosal blood flow in man, by studying surgically created colostomies. A local radioisotopic clearance technique utilizing a stable preparation of [125I]4-iodoantipyrine is employed. The indicator is injected directly into the colostomy under study and its gamma emission is recorded by a scintillation detector. A radioautographic study was carried out at laparotomy in humans to facilitate the interpretation of the recorded washout curves. The tracer was cleared from both the mucosa and submucosa throughout the period of study. Mucosal-submucosal blood flow was calculated according to Kety (1949) from the monoexponential clearance curves obtained, and amounted to 31.7 .+-. 11 ml/min 100 g (SD of an observation, n = 30). The results from 2 consecutive measurements in 17 patients showed that the mean change between 1st and 2nd readings was not significant (t test). The between-patient variation (12.2) was significantly greater than the within-patient variation (2.6) for consecutive recordings (F test; P < 0.01). The within-patient between-days variation (12.9; n = 10) was similar to the between-patient variation. The technique permits measurement of local colonic blood flow in man and by consecutive measurements, it may be used to evaluate local changes in blood flow following reflex or pharmacological stimulation.