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Titolo:
CALCIUM AND PROTEIN-KINASE-C PLAY AN IMPORTANT ROLE IN CAMPYLOBACTER JEJUNI-INDUCED CHANGES IN NA- TRANSPORT IN RAT ILEUM IN-VITRO( AND CL)
Autore:
KANWAR RK; GANGULY NK; KUMAR L; RAKESH J; PANIGRAHI D; WALIA BNS;
Indirizzi:
POSTGRAD INST MED EDUC & RES,DEPT EXPTL MED & BIOTECHNOL CHANDIGARH 160012 INDIA POSTGRAD INST MED EDUC & RES,DEPT EXPTL MED & BIOTECHNOL CHANDIGARH 160012 INDIA POSTGRAD INST MED EDUC & RES,DEPT PEDIAT CHANDIGARH 160012 INDIA POSTGRAD INST MED EDUC & RES,DEPT MICROBIOL CHANDIGARH 160012 INDIA
Titolo Testata:
Biochimica et biophysica acta. Molecular basis of disease
fascicolo: 2-3, volume: 1270, anno: 1995,
pagine: 179 - 192
SICI:
0925-4439(1995)1270:2-3<179:CAPPAI>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
INTESTINAL ELECTROLYTE TRANSPORT; ENTEROTOXIN-INDUCED DIARRHEA; INTRACELLULAR CA-2+; SECRETORY RESPONSE; CHLORIDE TRANSPORT; PHORBOL ESTERS; CALMODULIN; DISEASE; ACTIVATION; MECHANISM;
Keywords:
[CA2+](I); CALMODULIN; PROTEIN KINASE C; DIARRHEA; ENTEROTOXIN; (RAT); (C-JEJUNI);
Tipo documento:
Article
Natura:
Periodico
Citazioni:
61
Recensione:
Indirizzi per estratti:
Citazione:
R.K. Kanwar et al., "CALCIUM AND PROTEIN-KINASE-C PLAY AN IMPORTANT ROLE IN CAMPYLOBACTER JEJUNI-INDUCED CHANGES IN NA- TRANSPORT IN RAT ILEUM IN-VITRO( AND CL)", Biochimica et biophysica acta. Molecular basis of disease, 1270(2-3), 1995, pp. 179-192

Abstract

The pathophysiological mechanism of Campylobacter jejuni (enterotoxigenic) induced secretory diarrhoea remains least understood. To investigate the mechanism(s) involved, the unidirectional fluxes of Na+ and Cl- were measured across the C. jejuni live culture infected and control (non infected) rat ileum (unstriped), in vitro by Ussing technique under short circuit conditions, in the presence or absence of: Ca2+ ionophore A23187 (5 mu M), 1-verapami1 (100 mu M), calmodulin (CaM) antagonist W-7 (100 mu M), dantrolene (25 mu M), protein kinase C (PKC) activator PMA (100 ng/ml) and H-7 (60 mu M), selective inhibitor of PKC. There was net absorption of Na+ and enhanced Cl- secretion in infectedanimals while in control animals there was net absorption of Na+ and marginal secretion Cl-. Ca2+ ionophore A23187 mimicked the effects of C. jejuni infection whereas 1-verapamil had significant antisecretory effect on Na+ and Cl- secretion in infected animals. In vitro measurement of unidirectional Ca-45 fluxes in Ussing chamber experiments revealed net absorption of Ca2+ in infected rat ileum as compared to net secretion of Ca2+ in control rat ileum, These observations clearly indicate that there is increased stimulation of Ca2+ uptake from extracellular milieu to the enterocytes during C. jejuni-induced diarrhoea. The intracellular isolated from C. jejuni infected ileum as compared to the enterocytes from control ileum. The observed increase in [Ca2+](i) in enterocytes isolated from C. jejuni live culture supernatant treatedrat ileum further shows the involvement of enterotoxin in diarrhoeal process. Dantrolene decreased significantly C. jejuni-induced net Na+ and Cl- secretion but it could not reverse it to absorption suggestingthe partial involvement of Ca2+ mobilised from intracellular stores in mediating secretion. W-7 failed to inhibit the C. jejuni-induced netNa+ and Cl- secretion. In addition the CaM activity estimated in intestinal microvillar core remained same in both the control and C. jejuni infected animals. This indicates that C. jejuni-induced diarrhoea isnot mediated through the activation of Ca2+-CaM complex pathway of the Ca2+ messenger system. The PKC activator PMA, induced net secretion of Na+ and Cl- in the control animals but it could not enhance furtherthe C. jejuni-induced Na+ and Cl- secretion, suggesting that there isoverlapping effect of PMA and C. jejuni live culture infection. H-7 significantly inhibited (P < 0.001) net Na+ and Cl- secretion in the infected animals but had no effect on basal rat ileal Na+ and Cl- transport in control animals. This again suggest the activation of PKC signal in C. jejuni-induced ileal Na+ and Cl- secretion. Although intracellular cAMP levels were found to be significantly raised in the enterocytes isolated from C. jejuni live culture infected and C. jejuni culture supernatant treated rat ileum, the mechanism of interaction between cAMP and Ca2+ messenger system in infection remains undefined. Taken together, the present results therefore, indicate that enterotoxigenic C. jejuni live culture-induced Na+ and Cl- secretion is a calcium-dependent process where both increased Ca2+ entry from extracellular milieu and Ca2+ mobilization from intracellular stores result in increased enterocyte (Ca2+](i). The activation of PKC further appears to be the important intracellular mediator pathway involved in Ca2+-dependent stimulation of C. jejuni-induced diarrhoea.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 08/08/20 alle ore 09:02:31