PT  - JOURNAL ARTICLE
AU  - Ruth R. Levine
AU  - Edward W. Pelikan
TI  - THE INFLUENCE OF EXPERIMENTAL PROCEDURES AND DOSE ON THE INTESTINAL ABSORPTION OF AN ONIUM COMPOUND, BENZOMETHAMINE
DP  - 1961 Mar 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 319--327
VI  - 131
IP  - 3
4099  - http://jpet.aspetjournals.org/content/131/3/319.short
4100  - http://jpet.aspetjournals.org/content/131/3/319.full
SO  - J Pharmacol Exp Ther1961 Mar 01; 131
AB  - The absorption in 3 hours of benzomethamine from the small intestine has been studied in vivo in unanesthetized rats using single- and multiple-loop preparations. Fasting of animals and perfusing of the intestinal lumen with small quantities of water prior to the beginning of the experiments increased absorption above control levels. Absorption was unaffected by mild mechanical manipulation of the gut. The amount of benzomethamine absorbed was found to be dependent on the relative position in the gut of the absorbing surface. Absorption was greatest in the intestinal segments closest to the pylorus. The absorption of benzomethamine as a function of dose was studied in a large number of animals at 17 dose levels ranging from 0.5 mg/loop to 10 mg/loop. The dose-absorption curve was found to be a composite curve and not a single, linear function throughout the entire range of doses used. The slope of the segment of the curve corresponding to doses of 0.5 mg/loop to 2.0 mg/loop was significantly different from the slope of the segment of the curve from 2.0 mg/loop to 2.5 mg/loop, and the slope of the latter segment was significantly different from the slope of the curve from 2.5 mg/loop to 4 or 10 mg/loop. The alinearity of the dose-absorption curve led to the conclusion that more than one mechanism of transfer of benzomethamine across the gut wall must be involved in at least a part of the dose-response curve. The presence of intestinal mucous material in the drug solutions had the effect of uniformly decreasing the amount of benzomethamine absorbed per quantity administered. The amount of downward displacement of the curve varied directly with the amount of mucus in the injected solutions.