Studies on Hydragogue Drugs: Effect of Surfactants on cAMP Levels in the Rat Jejunal Mucosa in Short Time Experiments in Vivo

Abstract

Theophylline and the surface active agents specified below were instilled into the jejunum of anaesthetized rats, and the cAMP levels in the mucosal tissue determined after 7 1/2 and 15 min. incubation in vivo. Most experiments were done in rats prepared with two tied intestinal loops; one of these served as the control loop and the other as the stimulated loop. The surfactants (mmol/l) included dodecylsulphate (17), dioctylsulphosuccinate (5.6), cetrimonium bromide (4.1), deoxycholic acid (2.4 and 3.6) and Lubrol WX (0.5% w/v). Theophylline (10 mmol/l) caused a substantial increase in cAMP (110%±17, n=7 and 60%±8.9, n=10, respectively) and dodecylsulphate a minor and transitory increase (28.1%±3.8, n=10 and 11.7%±4.9, n=8). The other agents were without stimulatory effect on cAMP, allthough like dodecylsulphate they may significantly affect normal intestinal cation and glucose transport under these conditions. The results, therefore, do not suggest that stimulation of cAMP and intestinal secretion induced thereby is any significant phenomenon in the overall hydragogue effect of these agents, at least not in short term jejunal experiments.

Net Sodium and Glucose Transport in the Jejunum, Ileum and Colon of Anaesthetized Rats in Response to Intraluminal Theophylline and Anionic Surfactants

“…According to current view, elevated CAMP levels cause luminal water and electrolyte accumulation because of stimulation of cellular anionic efflux or inhibition of coupled sodium-chloride influx. However, an own study (Sund & Hillestad 1981) failed to demonstrate any increased formation of cAMP by DOSS in the rat jejunum under conditions where the drug significantly alters normal mucosal transport. Since, on the other hand, a substantial rise in cAMP by theophylline was demonstrated, the study suggested that theophylline but not DOSS under these conditions might cause transport alterations mediated via CAMP.…”

“…In the present work, these two possibilities have been explored by studying the influence of theophylline and DOSS on the abovementioned absorption processes in vivo. Another anionic surfactant, dodecylsulphate (=DDS), was also included, since this drug may induce some increased formation of CAMP (Briseid et al 1976(Briseid et al & 1977Sund & Hillestad 1981). A short account of this study has been presented elsewhere (Sund & Olsen 1978).…”