Intracerebroventricular administration of leptin-induced apoptosis in the rat small intestinal mucosa.

The localization of leptin and leptin receptors in the stomach and small intestine has been reported. Their function is still unknown, although leptin is a hormone that regulates appetite and fat-related metabolism. The small intestine is one of the important organs for regulating metabolism. The purpose of the present study was to investigate whether leptin regulates apoptosis in the small intestinal mucosa. Intestinal apoptosis was evaluated by percent fragmented DNA, electrophoresis, TUNEL staining, and western blotting analysis of caspase-3. Mucosal apoptosis in the rat jejunum and ileum was evaluated at 0, 3, 6, 12, and 24 hrs after injection. Rats were tested after ad libitum feeding and 24-hr fasting to exclude the anorectic effect of leptin. Leptin was injected intraperitoneally (ip) at a dose of 200 microg/rat and infused into the rat third cerebroventricle (icv) at a dose of 8 microg/rat. Leptin at a dose of 8 microg/rat significantly induced intestinal apoptosis in the small intestine at 3 and 6 hrs after icv administration in both ad libitum feeding and 24-hr fasted rats. This increase in apoptosis was not attenuated by vagotomy. Intestinal apoptosis increased 12 and 24 hrs after ip injection of leptin at a dose of 200 microg/rat. The peak of the increase in apoptosis in icv rats appeared earlier than that in ip rats. Leptin induced jejunal and ileal mucosal apoptosis in the rat, indicating that leptin might control intestinal function through the regulation of intestinal apoptosis.

Endoscopic injection sclerotherapy for esophageal varices in cirrhotic patients with hepatocellular carcinoma: risk factors for survival.

GOALS: We previously showed that endoscopic injection sclerotherapy (EIS) prolonged survival in patients with esophageal varices complicated by hepatocellular carcinoma (HCC) and liver cirrhosis. Here, we evaluated risk factors that affect EIS outcomes. Among factors, the difference between prophylactic and emergency EIS was of interest, and we analyzed precisely. STUDY: Subjects were 134 patients with esophageal varices complicated by HCC and liver cirrhosis: 38 underwent emergent therapy for bleeding varices and 96 underwent prophylactic sclerotherapy. RESULTS: During 2-year observation, 22 of the 38 (57.9%) and 38 of the 96 (39.6%) died. Analysis by univariate Cox's proportional hazard model indicated that prognosis of patients receiving emergency EIS was inferior to those with prophylactic EIS. However, multivariate Cox's analysis showed that emergency EIS itself extended survivals of those with esophageal varices complicated by HCC and liver cirrhosis. Patients' hepatic function (Child-Pugh classes) and tumor sizes were also statistically significant factors for survival. Neither prophylactic nor emergency EIS prolonged survival of patients with Child C hepatic function or those with HCCs larger than 5 cm. CONCLUSIONS: The prophylactic sclerotherapy for esophageal varices prolongs long-term survival of patients with liver cirrhosis and HCC, better than emergency therapy. However, EIS itself had no beneficial effect on patients with poor disease status.

iNOS enhances rat intestinal apoptosis after ischemia-reperfusion.

The aim of this study was to demonstrate (i) the role of iNOS (inducible nitric oxide synthase) on apoptosis in the rat intestinal mucosa after ischemia-reperfusion, and (ii) the effect of iNOS on the release of cytochrome c from mitochondria. The superior mesenteric artery was occluded for 60 min and was followed by a 60 min reperfusion. Rats were pretreated with an intraperitoneal injection of the following iNOS inhibitors: N-nitro-L-arginine methyl ester, aminoguanidine, and (1S,5S,6R,7R)-7- chloro-3-imino-5-methyl-2-azabicyclo [4. 1. 0] heptane hydrochloride (ONO-1714). Apoptosis was evaluated and NO(X) in the portal vein was assayed. The amount of iNOS, caspase-3, and cytochrome c were determined by a Western blot analysis. Intestinal mucosal epithelial mitochondrial dehydrogenase activity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoilium bromide. Ischemia-reperfusion increased intestinal mucosal apoptosis, NO(X) production in the portal vein, the amount of iNOS protein, and the release of cytochrome c, but not caspase-3. Inhibitors of iNOS significantly attenuated the induction of apoptosis, increased NO(X) production, and release of cytochrome c. Mitochondrial dysfunction was induced by ischemia-reperfusion, which was ameliorated by iNOS inhibitors. Our results indicate that iNOS is related to increased mucosal apoptosis in the rat small intestine after ischemia-reperfusion, which is partly explained by the release of cytochrome c from mitochondria to cytosols following mitochondrial dysfunction.