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Biomedical subjects

T Manabe

Publications and source records attributed to T Manabe.

At least 307 records · Page 17Linked to original sources
PubMed1993

Bradykinin involvement in the aggravation of acute pancreatitis in rabbits.

This study was designed to investigate the role of bradykinin in the aggravation of acute pancreatitis. After injection of bradykinin 2 micrograms/kg to anesthetized rabbits with cerulein-induced acute pancreatitis, the pancreatic blood flow through gastroduodenal and superior mesenteric arteries (GDAF and SMAF) was determined with electromagnetic blood flow meters, the serum amylase level was measured, and pancreatic tissue was observed histologically. In rabbits treated with a supramaximal dose of cerulein alone (20 micrograms/kg/h), pancreatic blood flow was decreased and the serum amylase level was increased significantly by the early phase, and histological examination showed acute edematous pancreatitis. In rabbits treated with cerulein and bradykinin, GDAF and SMAF were significantly diminished at 300 min (51 +/- 5% and 50 +/- 4%, respectively, p < 0.05), and the serum amylase level rose significantly at 180 and 300 min (730 +/- 130% and 1,190 +/- 200%, respectively, p < 0.01) compared with rabbits treated with cerulein alone, and histological examination revealed pancreatic necrosis and greater inflammatory cell infiltration. These findings suggest that bradykinin has an additive role in the aggravation of acute pancreatitis.

Acute Disease↗
PubMed1993

Synthesis and pharmacological properties of N-[4-[4-(1H-indol-3-yl) piperidinoalkyl]-2-thiazolyl]alkanesulfonamides as novel antiallergic agents.

A number of N-[4-[4-(1H-indol-3-yl)piperidinoalkyl]-2- thiazolyl]alkanesulfonamides (8--21) were synthesized and evaluated for their preventive effects on systemic anaphylaxis in guinea pigs. Structure-activity analysis revealed that methane- and ethanesulfonamide derivatives having a one to three methylene tether between the piperidine and thiazole rings exhibited potent activity but the introduction of a substituent on the indole part reduced the activity. Administration (100 mg/kg p.o.) of the four compounds 8, 9, 12, 13, together with ketotifen, oxatomide, terfenadine and azelastine as reference compounds, to mice revealed that only compound 8 caused no significant increase of the sleeping time induced by hexobarbital. In addition, compound 8 (10 mg/kg i.v.) did not change the electroencephalogram in conscious rabbits. These results led to the selection of N-[4-[4-(1H-indol-3-yl)piperidinomethyl]-2-thiazolyl]methanesulfon amide (8, FK613) for further development as a novel antiallergic agent. Clinical evaluation of FK613 is now in progress.

Anaphylaxis↗
PubMed1993

Effect of synthetic protease inhibitor on histologic changes and free radical activity in hamsters with pancreatic cancer.

To investigate the effects of synthetic trypsin inhibitors on pancreatic cancer, camostat (FOY-305) was administered orally to hamsters with experimental pancreatic cancer induced by diisopropanol nitrosamine (DIPN). The effect of free radicals on carcinogenesis was examined by measuring the tissue levels of the scavengers superoxide dismutase (SOD) and glutathione peroxidase (GSX-Px), and pancreatic tissues were examined histologically. Cancers developed in all hamsters that survived 24 weeks in the DIPN group and the FOY group, but 80% of the cancers in the DIPN group were tubular adenocarcinomas, and 91% of those in the FOY group papillary adenocarcinomas. The SOD activity in the DIPN group was significantly lower in the cancerous area and the borderline region than in the non-cancerous region and normal tissue. SOD activity in the cancerous and borderline regions was higher in the FOY groups than in the DIPN group. GSH-Px levels in the borderline and non-cancerous regions were significantly higher in the FOY group than in the DIPN group. These results suggest that the synthetic protease inhibitor slows the progress of pancreatic cancer by its free radical scavenging activity.

Adenocarcinoma↗
PubMed1993

A possible mechanism for gallstone pancreatitis: repeated short-term pancreaticobiliary duct obstruction with exocrine stimulation in rats.

The effects of single and repeated short-term (4 hr) obstruction of pancreaticobiliary duct (PBDO), with or without exocrine stimulation (intraductal hypertension) by cerulein infusion (0.2 micrograms/kg.hr), on the exocrine pancreas were evaluated in the rat. Single blockage of pancreaticobiliary duct for 4 hr caused a significant rise in serum amylase levels, pancreatic water content, and redistribution of lysosomal enzyme, cathepsin B from the lysosomal fraction to the zymogen fraction, which was considered to mean the colocalization of lysosomal enzymes with pancreatic digestive enzymes in the same subcellular compartment in acinar cells. In addition, the accelerated lysosomal and mitochondrial fragility was observed in the single pancreaticobiliary-duct-obstructed animals. Moreover, the repeated PBDO for 4 hr (2 hr in each obstruction and 1 hr of free flowing of pancreaticobiliary juice between two obstructions) caused more marked changes in almost the all parameters, and the repeated PBDO with intraductal hypertension caused an activation of trypsinogen in the pancreas, making more marked changes in almost the all parameters than the repeated PBDO only group. These results indicate that the present model of repeated PBDO with exocrine stimulation seems to be a pertinent model for gallstone pancreatitis in humans, and that redistribution of lysosomal enzymes and subcellular organellar fragility seem to play an important role in the pathogenesis of pancreatic injuries induced by PBDO, particularly by repeated PBDO with exocrine stimulation, probably via activation of trypsinogen to trypsin by lysosomal enzyme, cathepsin B.

Acute Disease↗
PubMed1993

Effect of postischemic reperfusion on the pancreas.

In an examination of the effect of ischemia and reperfusion on the generation of active oxygen species during pancreatic cell damage, a short-term ischemia and reperfusion model was prepared by the occlusion and reperfusion of both the anterior mesenteric artery and the celiac artery in rats. Following 60 minutes of occlusion plus 7 hours of reperfusion of the anterior mesenteric artery and the celiac artery, the serum concentrations of amylase and lipase rose significantly to 7 and 6 times the respective control values. After 30 minutes of occlusion plus 7 hours of reperfusion, or after 7 hours of occlusion without reperfusion, amylase and lipase levels were not changed significantly. The continuous intravenous infusion of superoxide dismutase (3600 U/kg/hour) in rats receiving 60 minutes of occlusion plus 7 hours of reperfusion suppressed the rise in serum amylase and lipase values to 25 percent of the values in the non-injected group. These results suggest that the active oxygen species which are generated by the short-term ischemia and reperfusion method injure the endothelium and cause hyperamylasemia and hyperlipasemia. Inhibition of the rise in serum amylase and lipase concentrations by pretreatment with a scavenger of active oxygen, superoxide dismutase, suggests that the active oxygen species are involved in the pathogenesis of acute pancreatitis.

Amylases↗
PubMed1993

Effect of prostaglandin E on the redistribution of lysosomal enzymes in caerulein-induced pancreatitis.

The redistribution of cathepsin B, a representative lysosomal enzyme, from the lysosomal pellet to the zymogen pellet in subcellular fractions and the colocalization of cathepsin B with digestive enzymes within acinar cells have been found during the early stage of caerulein-induced acute pancreatitis in the rat. This study investigated the protective effects of prostaglandins E1 and E2 on the exocrine pancreas in this experimental pancreatitis. Prostaglandin E2, but not E1, prevented the redistribution of cathepsin B along with the hyperamylasemia, and the increase in amylase and trypsinogen in the acinar cells in almost a dose-dependent manner, particularly at a dose of 100 micrograms/kg.hr of continuous infusion. These results suggest that subcellular organelle fragility is closely related to the pathogenesis of acute pancreatitis, and that prostaglandin E2 has an important cytoprotective effect on biological membranes as a stabilizer of lysosomal membrane.

Alprostadil↗
PubMed1993

Effect of prostaglandin E2 on cellular, lysosomal and mitochondrial fragility in caerulein-induced pancreatitis in rats.

The effects of prostaglandin E2 on the fragility of cellular and subcellular organelles in caerulein-induced acute pancreatitis were investigated in rats. PGE2 at doses of 50 and 100 micrograms/kg/hr infused for 2 hours before and during caerulein (5 micrograms/kg/hr for 3.5 hours) infusion significantly prevented the increased discharge of both amylase and lactate dehydrogenase from dispersed acini, and the leakage of cathepsin B from lysosomes and of malate dehydrogenase from mitochondria in the subcellular fraction in vitro. These results suggest that PGE2 has a cytoprotective effect against caerulein-induced pancreatitis by stabilizing cell and lysosomal and mitochondrial membranes.

Acute Disease↗
PubMed1993

Protective effects of therapy with a protease and xanthine oxidase inhibitor in short form pancreatic biliary obstruction and ischemia in rats.

The current study was done to evaluate the effects of short term (60 minutes) pancreatic biliary duct obstruction (PBDO) with intraductal hypertension (IDH) stimulated by secretin (0.2 clinical unit per kilogram per hour) and caerulein (0.2 microgram per kilogram per hour) plus 30 minutes of temporary pancreatic ischemia (ISCH) produced by ligation of celiac and superior mesenteric artery on the exocrine pancreas and protective effects of a new potent protease inhibitor, ONO3307 in combination with xanthine oxidase inhibitor, allopurinol, in this multifactor related model of acute pancreatitis in rats. Twelve hours after PBDO with IDH plus ISCH, we observed hyperamylasemia (23 +/- 3 units per milliliter) (p < 0.01); moderate pancreatic histologic changes; pancreatic edema (water content--81 +/- 2 percent) (p < 0.02), as well as the impaired amylase (2,889 +/- 328 units per kilogram per hour) (p < 0.01) and cathepsin B output (7 +/- 3 units per kilogram per hour) (p < 0.01) into the pancreatic juice of rats stimulated by caerulein (control group--serum amylase levels, 6 +/- 1 units per milliliter; pancreatic water content, 74 +/- 1 percent. Furthermore, PBDO with IDH plus ISCH caused the redistribution of lysosomal enzyme from lysosomal fraction (12 kilo times gravity pellet; 40 +/- 3 percent; p < 0.01) to zymogen fraction (1.3 kilo times gravity pellet; 38 +/- 3 percent; p < 0.01) (control group--12 kilo times gravity pellet, 59 +/- 2 percent; 1.3 kilo times gravity pellet, 24 +/- 2 percent) and the impaired pancreatic adenylate energy metabolism (0.79 +/- 0.02, p < 0.02) (control group--energy charge equals 0.88 +/- 0.01). Only PBDO with IDH caused no significant changes. Although only ONO3307 or allopurinol therapy showed the partial significant protective effects against pancreatic injuries, improving serum amylase levels, the administration of ONO3307 in combination therapy with allopurinol showed almost complete protective effects against the pancreatic injuries induced by PBDO with IDH plus ISCH (serum amylase levels, 9 +/- 2 units per milliliter; pancreatic water content, 76 +/- 2 percent; amylase and cathepsin B output, 7,127 +/- 946 and 18 +/- 3 units per kilogram per hour; 1.3 kilo times gravity pellet, 28 +/- 2 percent; 12 kilo times gravity pellet, 54 +/- 2 percent, and energy charge equals 0.85 +/- 0.02).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1992

Combined therapy of a cephalosporin, Shiomarin and a new potent protease inhibitor, E3123 in rat taurocholate-induced pancreatitis.

The role of infectious factors in the pathogenesis of acute pancreatitis and the protective effect of combined therapy with a new potent synthetic protease inhibitor, E3123, and a new potent synthetic cephalosporin, Shiomarin (SM) were examined in rat acute pancreatitis. Sodium taurocholate injection into the pancreatico-biliary duct of rats caused severe pancreatitis with a high mortality rate, characterized by hyperamylasemia, high amylase activity in ascitic fluid, and hyperendotoxemia and a high serum level of fibrin degradation products (FDP), redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction. In rats with E3123 infusion almost all parameters were improved, including mortality rate, serum and ascitic fluid amylase levels, plasma endotoxin and serum FDP levels, and distribution of lysosomal enzyme. But combination therapy with E3123 and SM was significantly more protective than E3123 therapy alone. These results indicate that infection plays an important role in the development of severe pancreatitis and that combination therapy with a new synthetic protease inhibitor and a new potent antibiotic may be useful in the treatment of severe pancreatitis.

Acute Disease↗
PubMed1992

"Cocktail" therapy for acute pancreatitis: combined therapy of protease inhibitor, xanthine oxidase inhibitor and platelet activating factor antagonist in rat caerulein-induced pancreatis.

A supramaximal dose of caerulein (5 micrograms/kg.hr for 3.5 hours) caused an acute pancreatitis with marked hyperamylasemia and intense interstitial edema in rats. In this model of pancreatitis, the redistribution of lysosomal enzyme in acinar cells as well as the increased lysosomal and mitochondrial fragility were also observed. The combined therapy of a low molecular weight protease inhibitor, FOY, a synthetic platelet activating factor (PAF) antagonist, CV 6209, and a xanthine oxidase inhibitor, allopurinol produced more significant improvements in all the parameters examined than the therapy of any only one of these three agents, each only one therapy exerting a partial significant protective effect. These results indicate that several factors, such as unknown proteases activities, PAF and oxygen-derived free radicals may be involved in the pathogenesis of pancreatic injuries in this caerulein-induced pancreatitis. These results also suggest that such a combined therapy of different kinds of agents, whose therapeutic mechanisms are also different, is useful in the clinical treatment of acute pancreatitis.

Acute Disease↗
PubMed1992

Flow cytometric analysis of nuclear DNA content of duct cell carcinoma of the pancreas.

BACKGROUND: This study was designed to evaluate the efficacy of nuclear DNA content analysis in determining the prognosis of carcinoma of the pancreas. METHODS: Resected and paraffin-embedded specimens from 72 patients with duct cell carcinoma of the pancreas were examined, and flow cytometry was used to explore the relationship between DNA ploidy and TNM classification or histologic grade. RESULTS: DNA aneuploidy was found histologically in 42.9%, 56.8%, and 71.4% of Grade 1, 2, and 3 tumors, respectively. DNA ploidy showed a statistically significant correlation with T category and retroperitoneal invasion. The cumulative survival rate of patients with retroperitoneal invasion was shorter than that of those without retroperitoneal invasion. Among the patients with retroperitoneal invasion, those with DNA aneuploidy had a significantly shorter survival time than did those with DNA diploidy. CONCLUSIONS: The DNA ploidy pattern, in combination with the presence or absence of retroperitoneal invasion, appears to be useful in predicting the prognosis for duct cell adenocarcinoma of the pancreas.

Adult↗
PubMed1992

Effect of hypothermia on pancreatic acinar cells in rats.

This study was designed to evaluate the effects of direct pancreatic surface cooling on the exocrine pancreas. We measured the changes in serum amylase levels, pancreatic water, amylase and cathepsin B as a lysosomal enzyme, content, histological changes of acinar cells, and the subcellular distribution of cathepsin B after 1-2- and 3-hours of direct pancreatic cooling in rats. In addition, we evaluated the in-vivo amylase and cathepsin B output stimulated by caerulein, in-vitro lysosomal and mitochondrial fragility as well as the pancreatic adenylate energy metabolism. 2-hours cooling showed slight yet significant changes, but 3-hours cooling caused most significant changes including hyperamylasemia, increased pancreatic amylase content and very mild histological changes. Furthermore, 3-hours cooling caused a remarkable redistribution of cathepsin B activity from the lysosomal fraction to the heavier zymogen fraction, and colocalization of the lysosomal enzyme with the digestive enzyme, the impaired amylase and cathepsin B output into pancreatic juice stimulated by caerulein as well as the accelerated fragility of lysosomes and mitochondria, and impaired pancreatic adenylate energy metabolism. These results indicate the impaired exocrine pancreatic functions induced by direct pancreatic cooling injury induced by cooling as shown in the other models of experimental pancreatitis. Moreover, this cooling model of pancreatitis seems to be useful in understanding the early events in the pathogenesis of acute pancreatitis, and we must take these "cold" injuries of exocrine pancreas into considerations, particularly in the pancreas transplantation and in other major abdominal surgeries where the pancreas is exposed to cooling.

Amylases↗
PubMed1992

Fragility of subcellular organelles induced by pancreatic duct obstruction in rabbits.

The effects of short-term (6 hours) pancreatic duct obstruction on the possible secretion of lysosomal enzyme into pancreatic juice and subcellular lysosomal and mitochondrial fragility were investigated in rabbits. Caerulein stimulated the secretion of amylase and cathepsin B into pancreatic juice in controls. Blockage of the pancreatic duct for 6 hours caused a significant decrease of amylase and cathepsin B output into pancreatic juice, and a significant rise in portal serum amylase and cathepsin B levels, and pancreatic amylase content and an accelerated leakage of cathepsin B from lysosomes and malate dehydrogenase from mitochondria in in-vitro preparations, as well as redistribution of cathepsin B in acinar cells. These changes tended to continue for up to 12 hours after removal of the pancreatic duct obstruction. These results indicate that under physiological conditions, lysosomal enzymes are secreted into the pancreatic juice in response to stimulation by gut hormones and that increased lysosomal fragility, mitochondrial fragility and impaired pancreatic energy charge levels are closely related to the pathogenesis of pancreatic injury in this model. Moreover, zymogen colocalized with lysosomal enzyme after duct obstruction was secreted into pancreatic juice in increased amount together with digestive enzymes; these findings suggest that lysosomal enzymes play important pathophysiological roles in pancreatic juice.

Amylases↗
PubMed1992

Effect of short-termed pancreatico-biliary duct obstruction on lysosomal enzyme in rats: protective effect of a potent new protease inhibitor, E-3123.

To investigate the mechanism by which the pancreatic acinar cells are injured in animals with an obstructed common channel, we measured the amount of lysosomal enzymes and of amylase in the pancreatico-biliary juice in rats with pancreatico-biliary duct obstruction (PBDO). We tested the protective effect of a new potent synthetic protease inhibitor, E3123 (4-guanidinobenzoate methanesulfonate), on the exocrine pancreas in this model of PBDO and secretin infusion. Blockage of PBD for 4 hours and secretin (0.2 CU/kg.hr) infusion caused a significant rise in portal serum amylase and cathepsin B levels, pancreatic water content, and pancreatic amylase content, as well as redistribution of cathepsin B in acinar cells. These changes tended to continue for 12 hours after the removal of PBDO and disappeared at 24 hours. All the changes induced by PBDO with secretin infusion were no longer observed at 48 hours. The administration of 5 mg/kg.hr of E3123 during PBDO markedly attenuated all the parameters examined in this study. Thus, it had a significant protective effect on acinar cells in this model. E3123 in a dose of 2 mg/kg.hr had a partial, but significant, protective effect. These results indicate the possible usefulness of E3123 in the treatment of pancreatic duct obstructed pancreatitis.

Acute Disease↗
PubMed1992

Improved survival in mice with diet-induced pancreatitis treated with new potent protease inhibitor, E-3123 and a broad spectrum antibiotic, cefmetazole.

This study was designed to evaluate the infectious factor in the pathogenesis of acute pancreatitis and the effects of a combination therapy with a new potent protease inhibitor, E-3123, and a broad spectrum antibiotic cefmetazole (CMZ) in mice with CDE diet-induced severe acute pancreatitis. Combination therapy with E-3123 and CMZ showed significant protective effects against the high mortality rate, increased serum amylase and ascitic fluid amylase levels, pancreatic amylase and lysosomal enzyme content, plasma endotoxin levels, redistribution of lysosomal enzyme from the lysosomal to the zymogen fraction, lysosomal and mitochondrial fragility, and also improved the histological findings when compared with the E-3123 alone. These results suggest that infections factors play an important role in the development of severe acute pancreatitis and that protease inhibitors in combination with antibiotics may be clinically beneficial.

Acute Disease↗