Cholera toxin effects on fluid secretion, adenylate cyclase, and cyclic AMP in porcine small intestine.
AUTOR(ES)
Forsyth, G W
RESUMO
The effects of cholera toxin on mucosal cyclic nucleotide concentrations and on net fluid secretion in the porcine small intestine are reported. Cholera toxin causes net secretion of fluid into the small intestine of weanling pigs, and secretory rates are dependent on the dose of the toxin placed in intestinal loops. Intestinal secretion due to cholera toxin exposure was not consistently accompanied by elevated concentrations of mucosal cyclic AMP or cyclic GMP. Net fluid fluxes in individual loops did not correlate with mucosal cyclic AMP concentration in the same loop. Jejunal adenylate cyclase was activated to a lesser extent in pigs, compared with rabbits, after in vivo treatment with cholera toxin. In vitro activation in cell-free homogenates was similar for both species. Papaverine was similar to cholera toxin in causing fluid secretion without cyclic AMP accumulations, but 3-isobutyl-1-methyl xanthine significantly increased cyclic AMP concentration and induced fluid secretion in pigs. Weanling pigs appeared to differ from rabbits in having a secretory response to cholera toxin which was independent of elevations in total mucosal cyclic AMP concentration.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=422005Documentos Relacionados
- Effects of cholera toxin on adenylate cyclase. Studies with guanylylimidodiphosphate.
- Interaction of cholera toxin and membrane GM1 ganglioside of small intestine.
- Heat-stable enterotoxin of Escherichia coli: in vitro effects on guanylate cyclase activity, cyclic GMP concentration, and ion transport in small intestine.
- Studies on the Mode of Action of Cholera Toxin: EFFECTS ON SOLUBILIZED ADENYLATE CYCLASE
- Reconstitution of cholera toxin-activated adenylate cyclase.
