Studies on the pathophysiological mechanism of Campylobacter jejuni-induced fluid secretion in rat ileum

Calcium has been reported to play an important role in regulating the intestinal electrolyte transport via Ca2+/calmodulin (CaM) and/or protein kinase C (PKC) systems. The role of Ca2+, CaM and PKC in the pathogenesis of Campylobacter jejuni-induced fluid accumulation was studied in vivo in ligated rat ileal loops. Calcium ionophore A23187 (5 microM) and PKC activator, phorbol-12-myristate-13-acetate (PMA, 100 micrograms kg-1) when injected alone induced fluid accumulation in the control loops. However, these modulators did not enhance further C. jejuni-induced fluid accumulation when injected along with C. jejuni live culture in the experimental loops. Both 1-verapamil (100 microM) and PKC antagonist, H-7 (15 micrograms/ml-1) significantly reduced C. jejuni-induced fluid accumulation (P < 0.001). The effect of CaM antagonist W-7 (60 microM) on C. jejuni-induced fluid secretion was not significant (P > 0.05). Our findings suggest that both Ca2+ and PKC appear to be the important second messengers involved in the stimulation of intestinal fluid accumulation in C. jejuni infection.