Salt absorption

BJ Aungst, NJ Rogers, E Shefter. (1988). Comparison of nasal, rectal, buccal, sublingual, and intramuscular insulin efficacy and the effects of a bile salt absorption promoter. J Pharmacol Exp Therap 244 23-27. 

Isolated perfused gills subjected to 26,000 CN-/L, as KCN Inhibited sodium chloride absorption across gill epithelium effect reversible if exposure <5 min and nonreversible if >30 min salt absorption effect regulated by (Na+ + K+) ATPase 11... 

The thick ascending limb is a major site of salt absorption and a principal locus of action of an important group of diuretics. Approximately 25% of the filtered sodium is reabsorbed by the thick ascending limb of Henle s loop. Sodium transport in this nephron segment is mediated by Na+-K+-2C1 cotransport (Fig. 21.3). This transporter is present only on the apical, or urine, side of the tubule cells. Although K+ is taken up by the transporter, little net K+ reabsorption occurs in the thick ascending limb because much of the absorbed K+... 

There is very little information on the preparation of polysaccharide adducts. Senti and Witnauer28 have reported the only polysaccharide adducts of a definite stoichiometric type. Their method consisted of equilibrating the alkali metal hydroxide adduct (see Section III) of the polysaccharide with the proper salt in 20-25% aqueous ethanolic medium. Absorption of salt, with concurrent displacement of hydroxide, increases with increase in concentration of the salt in the exchange medium. Above certain concentrations of the salt, absorption can become virtually independent of the concentration, indicating that maximum absorption has been attained and that a stable adduct of definite stoichiometric compo-... 

Most studies of the local actions of opioids on the intestinal mucosa have utilized muscle-stripped sheets of ileal mucosa with attached submucosa mounted in Ussing flux chambers. Peptidase-resistant enkephalin derivatives such as DPDPE decrease short-circuit current, an electrical measure of active transepithelial ion transport, across isolated mucosal sheets from the guinea pig ileum [46,127,128], rabbit ileum [129-131], mouse jejunum [132], and pig distal jejunum/ileum [133]. This effect, which occurs after the application of opioid agonists to the serosal aspect of epithelial sheets, is due to an increase in electroneutral salt absorption and a decrease in electrogenic chloride secretion [46,132,133], In contrast to enkephalin derivatives, opiate alkaloids have limited effects on active transepithelial transport of ions [69]. Pretreat-... 

In a study of salt absorption, a solution of NaCi was placed in the lumen of the gut with a tube, and the absorption of ions was monitored by withdrawing samples of fluid at various times. Devise a mechanism by which the enterocyte can absorb sodium ions from a solution of sodium sulfate in the lumen, Sulfate ions are absorbed poorly by the gut, so the mechanism should depict sulfate ions staying in the lumen. Would the contents of the lumen become more acidic or more basic as more and more sodium is absorbed (See Turnberg etstl., 1970). 

Safflower oiL 362 Salivary glands, 58-60 SaH fortified, 736, 737 Salt absorption, 118-119 Salt-sensitive/insensitrve people, 729 SAM, see S-Adenosyimethionine Sarcomere, 790... 

Intestinal absorption of salt and water is stimulated by angiotensin II and aldosterone. Angiotensin II stimulates the absorption of Na by the jejunum and ileum. Nerves leading from the brain to the gut may also control sodium absorption by the gut. Angiotensin II in the brain may play a part in this mechanism. Aldosterone seems to have no effect on salt absorption by the small intestines. The kidney is controlled by the nervous system. The nervous control of salt absorption by the kidney seems to play only a minor role in salt balance. Aldosterone stimulates the colon to absorb Na. Plasma angiotensin II is not thought to have a direct effect on salt absorption by the colon. The material described here is outlined in Figure 10.11. 

Guan, Y Hao, C Cha, D.R. et al. (2005) Thiazolidinediones expand body fluid volume through PPARy stimulation of ENaC-mediated renal salt absorption. Nature Medicine, 11, 861-866. 

Different small intestinal sites of absorption for different micellar constituents have also been an argument for uptake of monomers instead of micelles. Whereas the major part of the lipolytic products are absorbed in the proximal part of jejunum, the site of bile salt uptake has been said to be the distal ileum. Recent investigations of the quantitative role of different parts of the small intestine for bile salt absorption suggest that the role of the distal ileum has been overestimated. Sklan et al. [73] found that about 50% of bile salts of endogenous origin were absorbed in the proximal half of the rat small intestine in vivo. A similar investigation was performed by McCUntock and Shiau [74], who injected a bolus dose of bile salts into the jejunum of rats with a bile fistula. They found that 60% of taurocholate was absorbed before the bolus reached distal ileum. 

The rather extensive literature on the absorption of dyes, especially direct dyes, by cellulose has been reviewed by Vickerstaff. Vickerstaff has also reviewed the literature on salt absorption however, three papers might be mentioned as pertinent to the work presented here, namely, those of Usher and Wahbi, Neale and Standring, and Farrar and Neale, and particularly the last. 

All of the salt absorption measurements were made using radioactive tracer techniques dye uptakes were measured by a change-of-concentration method. Details of each method are given below. 

Essentially three different measurements were made room-temperature ion absorption measurements, high-temperature ion absorption measurements, and dye absorption measurements. Both high- and room-temperature salt absorption measurements were made using single fiber samples and radioactive salts the dye absorption measurements were made using bulk samples. 

Before discussing the mechanism of salt absorption by viscose fibers, it is perhaps desirable to consider the stability of the viscose monofils used. 

Sutcliffe, J.F. Mineral salts absorption in plants Pergamon Press New York, NY (1962). 

The purified waste water must also satisfy the norm regarding salinity, i.e. the total content of salts. Absorption of ions in ion exchangers, which must be generated by using a four to ten-fold molar excess of salt with respect to the number of... 

Saunders, DJI., and SUlery, J. (1976) Lecithin Inhibits Fatty Acid and Bile Salt Absorption from Rat Small Intestine in Vivo, Lipids 11,83(U832. 

Zahner J, Smith JJ, Karp PH, Widdicomhe JH, Welsh MJ. Loss of CFTR chloride channels alters salt absorption by cystic fibrosis airway epithelia in vitro. Mol Cell 1998 2 397. 

H. Lundegardh, An Electrochemical Theory of Salt Absorption and Respiration, Nature 143, 203 (1939). 

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