The results of the present study suggest that MP and lligustrazine may improve epithelial barrier function and exert a stimulatory effect on colonic anion secretion, indicating the potential use of MP and its active ingredients for improvement of GI tract host defense and alleviation of constipation often seen in the elderly.

AIM:To investigate the effect of tetramethylpyrazine (ligustrazine, TMP) on the secretion of exocrine pancreas (and biliary). METHODS:In in vivo study, we investigated the effect of TMP on the secretion of pancreatic-bile juice (PBJ) in rats. Using human pancreatic duct cell line, CAPAN-1, combined with the short-circuit current (I SC ) technique we further studied the effect of TMP on the pancreatic anion secretion. RESULTS:Administration of TMP (80 mg/kg, ip) significantly increased the secretion of PBJ (P<0.05), but the pH of PBJ and the secretion of pancreatic protein were not significantly affected. Basolateral addition of TMP produced a dosedependent increase in I SC (EC 50 =1.56 mmol/L), which contained a fast transient I SC response followed by a slow decay. Apical application of Cl -channel blockers, DPC (1 mmol/L), decreased the response by about 67.1 % (P<0.001), whereas amiloride (100 µmol/L), a epithelial sodium channel blockers, had no effect.