The measurement of dog gastric mucosal blood flow by radioactive aniline clearance compared with amidopyrine clearance

Abstract

SUMMARY1. Methods for the estimation of radioactive aniline in body fluids are described. The recovery of aniline added to blood, plasma and gastric juice was over 90 % of the recovery from saline.2. In the doses used aniline caused methaemoglobinaemia of 5-11 % of total haemoglobin. No other effect was detected. Gastric secretion was also unaffected. 3. Aniline clearance increased in parallel with acid secretion from Heidenhain pouches in conscious dogs and in anaesthetized dogs. In conscious dogs the ratio of aniline clearance to acid secretion was significantly higher for histamine stimulation than for pentagastrin stimulation.4. Aniline and amidopyrine clearances were compared simultaneously in the same dogs. Aniline clearance was about 80 % of amidopyrine clearance.5. The proportion of aniline bound to plasma proteins was measured by two methods and found to be 25 %. When aniline clearance was corrected for plasma binding, aniline and amidopyrine clearances were equal.

Effects of Aspirin‐like Drugs on Canine Gastric Mucosal Blood Flow and Acid Secretion

“…Food was withheld for 18 h before experiments, but water was allowed. Mucosal blood flow (MBF) (ml/min) was estimated by clearance of radioactive aniline (Curwain & Holton, 1973), and pouch acid secretion (gmol H+/min) was measured by titration against 0.1 M NaOH with phenolphthalein as indicator. Where appropriate, acid output, MBF and changes in their ratio were calculated.…”

“…Aspirin 20 mM in Sorensen's phosphate buffer 0.67 M, pH 6.0 formed buffered aspirin. When aspirin was studied without secretory stimulation 80 mm HCI was instilled into the pouch throughout to prevent back-diffusion of aniline (Curwain & Holton, 1973) (1-2 ,ug/ml). Prostaglandins E2 and F2a (50-300 ng/ml) always caused contraction, but lower concentrations were ineffective; prostaglandin FlIa (0.3-3 gg/ml) had no effect or caused contraction.…”

Gastric mucosal blood flow during pentagastrin‐ and histamine‐stimulated acid secretion in the rat

“…Of the other weak bases which satisfy the necessary criteria for use in gastric clearance measurements, aniline is readily available as the 'IC isotope. Moreover, recent studies in the dog have shown that clearance of both aminopyrine and ['4C]-aniline gives similar estimates of MBF (Curwain & Holton, 1971, 1973.…”

ANTAGONISM OF VASODEPRESSOR AND GASTRIC SECRETORY RESPONSES TO HISTAMINE BY THE H2‐RECEPTOR ANTAGONISTS, RANITIDINE AND CIMETIDINE, IN THE ANAESTHETIZED DOG

“…There have been only a few reports of the use of the anaesthetized dog with an acute gastric fistula for the assessment of gastric acid secretion (Black, Fisher & Smith, 1958;Curwain & Holton, 1973). This preparation has the advantage of allowing simultaneous measurement of gastric secretion, cardiovascular and respiratory parameters.…”