The permeability coefficient of albumin of the isolated rat mesentery Modification by some mediators of inflammation, cyclic AMP and calcium

• Published in: Biochimica et biophysica acta Vol. 588; no. 2; pp. 219 - 231
• Main Authors: Kahn, André, Brachet, Etienne
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 03.12.1979
• Subjects: Animals; Bradykinin - pharmacology; Bucladesine - pharmacology; Calcium - metabolism; Carbachol - pharmacology; Cyclic AMP - metabolism; Histamine - pharmacology; In Vitro Techniques; Isoproterenol - pharmacology; Male; Mesentery - metabolism; Permeability; Prostaglandins F - pharmacology; Rats; Serotonin - pharmacology; Serum Albumin, Radio-Iodinated - metabolism; Theophylline - pharmacology
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(79)90205-8

In order to study the mechanisms whereby mediators of inflammation exert their exudative effects, we used isolated rat mesentery placed as a separation membrane between the two compartments of a diffusion cell. In this experimental arrangement, the permeability coefficient of albumin ( P A) can be easily computed from the equilibration rate of 125I-labelled albumin added to one compartment. Histamine, bradykinin, serotonin and prostaglandins A 1, A 2, E 1, E 2, F 1α and F 2α all increased P A to some extent, the maximal values being approx. +60%. Dibutyryl-cyclic AMP, theophylline and isoproterenol also increased P A, thus suggesting involvement of cyclic AMP. Direct measurements of this nucleotide confirmed this hypothesis; furthermore, a linear relation between cyclic AMP levels and P A could be demonstrated. In contrast, cyclic GMP is probably not involved in the control of P A. Calcium-depleted tissues had a low P A (approx. 40% below controls), and did not respond to exogenous prostaglandin E 1. These results suggest that transmesenteric passage of albumin is at least partly controlled by cyclic AMP and intracellular Ca 2+ levels.