Increased level of cAMP in the rat intestinal mucosa caused by sodium lauryl sulphate

Fate and effects of the surfactant sodium dodecyl sulfate

Sodium dodecyl sulfate is the most widely used of the anionic alkyl sulfate surfactants. Its surface-active properties make it important in hundreds of household and industrial cleaners, personal care products, and cosmetics. It is also used in several types of industrial manufacturing processes, as a delivery aid in pharmaceuticals, and in biochemical research involving electrophoresis. SDS synthesis is a relatively simple process involving the sulfation of 1-dodecanol followed by neutralization with a cation source. Purification is accomplished through repeated extraction. It is available commercially in both broad-cut and purified forms. Although its environmental occurrence arises mainly from its presence in complex domestic and industrial effluents, SDS is also directly released in some applications (e.g., oil dispersants and pesticides). Although surfactants are known to significantly contribute to the toxicity of some effluents, no official water quality standards currently exist. Research has shown SDS to be highly biodegradable by a large number of naturally occurring bacteria, and degradation is generally reported to be > or = 90% within 24 hr. The process involves initial enzymatic sulfate liberation and conversion to dodecanoic acid, followed by either beta-oxidative shortening or elongation and desaturation. All surfactant properties are lost after initial sulfate hydrolysis. SDS can enhance absorption of chemicals through skin, gastrointestinal mucosa, and other mucous membranes. Thus, it is used in transepidermal, nasal, and ocular drug delivery systems and to enhance the intestinal absorption of poorly absorbed drugs; enhancement is concentration dependent. Human exposure is mainly through oral ingestion and dermal contact, although cases of respiratory exposure are known. The main sources of daily intake are ingestion of personal care products, residues on insufficiently rinsed utensils, and contaminated drinking water. Uptake, distribution, and excretion of SDS are all rapid. In fish, uptake in various tissues plateaus within 24-72 hr, with elimination occurring within < 24-48 hr; selective accumulation occurs in the hepatopancreas and gall bladder. In mammals, it is readily absorbed via the intestine, colon, and skin. Metabolism is similar in fish and mammals, proceeding from initial omega-oxidation to a carboxylic acid, then to beta-oxidation to butyric acid 4-sulfate, which is finally nonenzymatically desulfurated to gamma-butyrolactone and inorganic sulfate. SDS elicits both physical and biochemical effects on cells, with the membrane the primary target structure. Effects are concentration dependent and range from loss of barrier function and increased permeability to complete cell lysis. Hemolysis in mammals is pH dependent.(ABSTRACT TRUNCATED AT 400 WORDS)

The action of six lipid perturbing substances on hormone receptor adenylate cyclase complex in turkey erythrocytes and intestinal mucosa cells

Adenylate cyclase and beta-receptor binding in turkey erythrocytes is studied under the influence of dioctyl sodium sulphosuccinate (DSS), sodium dodecyl sulphate (SDS), sodium deoxycholate (DOC), filipin, oxyphenisatine and ethanol. Intact and lysed erythrocytes and erythrocyte membranes were investigated. In general the fluoride stimulated enzyme was most resistant to the action of the substances followed by the ligand binding, the hormone stimulated enzyme being most sensitive to the action of the substances. However, in certain ranges of concentrations, DSS, SDS, filipin and oxyphenisatine could further stimulate the fluoride stimulated enzyme. The adenylate cyclase in intestinal mucosa cells was studied in the presence of DSS, SDS, DOC and oxyphenisatine. The fluoride stimulated enzyme was here less stable than the basal enzyme activity, and two of the substances (SDS and oxyphenisatine) stimulating the erythrocyte enzyme could not stimulate the fluoride stimulated intestinal mucosa cell enzyme.

Studies on hydragogue drugs: effect of surfactants on cAMP levels in the rat jejunal mucosa in short time experiments in vivo

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 71/2 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, although 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

Osmotically balanced solutions of sodium chloride and glucose (5-150 mmol/l) were instilled into rats prepared with two tied intestinal loops (jej-col or il-col). Luminal accumulation or disappearance of Na and glucose after 15 min. was determined, and the parameters of the linear regression lines of net Na flux (y) with initial Na concentration (x) calculated. Control cation and glucose transport were changed by dioctylsulphosuccinate and dodecylsulphate in the way described by Sund & Matheson (1978). Theophylline (10-25 mmol/l) on the other hand did not alter glucose disappearance, and had a distinctly dissimilar effect on net Na transport compared to the surfactants. This could be described as a parallel displacement of the control regression lines to the right, without improvement in correlation. This effect of theophylline was greatest in the ileum, where mean luminal Na concentration corresponding to zero net transport was raised from about 70 mmol/l under control condition to values above 200 mmol/l. The results are consistent with the view that theophylline mainly affects transcellular and the surfactants mainly paracellular sodium transport, and do not support the theory that the effect of dioctylsulphosuccinate on intestinal transport is related to an activation of the mucosal adenylate cyclase/cAMP system, at least not in short term experiments.