Changes of neuronal acetylcholine receptor alpha 7 of peritoneal macrophage in experimental acute pancreatitis treated by Chaiqin Chengqi Decoction

To investigate effect of Chaiqin Chengqi Decoction (CQCQD) on changes of neuronal acetylcholine receptor alpha 7 (nAChR alpha 7) of peritoneal macrophages in acute pancreatitis (AP). Eighteen Kunming mice were equally randomized into the control group, AP group and CQCQD treatment group. AP was induced by two intraperitoneal injections of 4 g/kg L-arginine at 1 h apart, while control mice received saline injections. At 72 h after the first injection of L-arginine, mice in the treatment group were intragastrically administered 0.1 mL/10 g CQCQD every 2 h for 3 times, whilst mice in the other two groups received the same amount of saline feeding. Mice were sacrificed by cervical dislocation 2 h after the last feeding of either CQCQD or saline. Peritoneal macrophages were collected for determination of nAChR alpha 7 mRNA and protein expression. Serum was collected for detection of interleukin-6 (IL-6), IL-10 and acetylcholine (ACh) levels, and pancreas was for histopathology analysis. The CQCQD treatment significantly ameliorated the severity of AP as evidenced by reducing the pancreatic histopathology score (4.5 +/- 0.5 vs. 6.2 +/- 1.7, P < 0.05) and the serum IL-6 levels (1228.3 +/- 419.2 pg/mL vs. 1589.6 +/- 337.3 pg/mL, P < 0.05). The mRNA and protein expression of nAChR alpha 7 of the peritoneal macrophages in the AP group were similar to the control group (P > 0.05), but were significantly up-regulated after the CQCQD treatment (P < 0.05). The serum ACh levels in the AP group were significantly lower than those in the control group (3.1 +/- 0.6 mu g/mL vs 4.8 +/- 0.7 mu g/mL P < 0.05), but were significantly increased after the CQCQD treatment (5.6 +/- 1.5 mu g/mL vs 3.1 +/- 0.6 mu g/mL, P < 0.05). CQCQD is protective against L-arginine-induced AP through mechanisms involving nAChR alpha 7 of peritoneal macrophages.