Itsuro Nakano

Autoimmune pancreatitis as a new clinical entity : Three cases of autoimmune pancreatitis with effective steroid therapy

The most common forms of chronic pancreatitisare related to alcohol ingestion, whereas the entity ofnon-alcohol-associated (idiopathic) pancreatitis ispoorly understood. Autoimmunity has been suggested as a possible etiologic factor of idiopathicchronic pancreatitis. A total of 362 Japanese patientsunderwent endoscopic retrograde pancreatography (ERP)for suspected pancreatic disease, and 161 were diagnosed with chronic pancreatitis. Among them, we foundthree cases (1.86% incidence) of unique chronicpancreatitis, in which ERP revealed diffuse narrowing ofthe main pancreatic duct with an irregular wall. We diagnosed these three patients as havingpancreatitis associated with an autoimmune mechanismmorphologically and biochemically and started them onsteroid therapy. The characteristics of the these three patients were as follows:hypergammaglobulinemia, eosinophilia, ultrasonographyshowing hypoehoic diffuse swelling in the pancreas(sausage-like appearance), ERP showing diffuse narrowingof the main pancreatic duct with irregular like thumbprintlike marks,reversible exocrine insufficiency, and positiveanti-carbonic anhydrase II antibody. After one month ofthe treatment with steroids, pancreatitis dramatically improved morphologically and enzymatically.Here we describe these cases of the suspected autoimmunechronic pancreatitis. We must recognize the concept andthe features of autoimmune pancreatitis in order to avoid unnecessary surgery as pancreaticcancer.

Protective effect of nitric oxide on development of acute pancreatitis in rats

Nitric oxide (NO) has been implicated to regulate pancreatic circulation, promote capillary integrity, and inhibit leukocyte adhesion. We investigated the role of NO in the development of pancreatitis. Nitro-l-arginine, an inhibitor of NO synthase, in total dose of 35 mg/kg body wt was infused in the rats with edematous pancreatitis induced by two intraperitoneal injections of cerulein (20 μg/kg).l-Arginine (125 or 250 mg/kg), a NO donor was intravenously administered twice in the rats with hemorrhagic pancreatitis induced by waterimmersion stress plus two intraperitoneal injections of cerulein (40 μg/kg). The degree of pancreas edema, serum amylase levels, and histologic alterations were investigated. Nitro-l-arginine exacerbated cerulein-induced pancreatitis and caused a decrease in pancreatic blood flow.l-Arginine ameliorated the severity of hemorrhagic pancreatitis dose dependently and improved the pancreatic blood flow. These findings suggest that NO could confer protection against the development of hemorrhagic pancreatitis, probably through improvement of the pancreatic microcirculation.

Effect of endothelin-1 on the development of hemorrhagic pancreatitis in rats

BACKGROUND It has been hypothesized that microcirculatory disturbance plays an important role in the development of severe pancreatitis. In this study we investigated the effects of exogenous endothelin-1 on the development of severe pancreatitis in rats. METHODS Acute pancreatitis was induced by two intraperitoneal injections of cerulein (10 micrograms/kg body weight). Endothelin-1 was administered via an abdominal aortic catheter as a bolus of 250-750 pmol/kg BW every hour for 4 h. RESULTS Remarkable morphologic changes in the pancreas, including hemorrhage, and increases in serum amylase level and active elastase content in pancreatic tissue were observed in rats treated with cerulein plus endothelin-1 in a dose-dependent manner 5 h after the first cerulein injection. Local pancreatic blood flow decreased significantly, and microcirculatory disturbances in the pancreas were demonstrated. CONCLUSIONS These results suggest that endothelin-1 causes pancreatic microcirculatory disturbance and might be a contributing factor in the aggravation of acute pancreatitis.

New chronic pancreatitis model with diabetes induced by cerulein plus stress in rats

To establish a new experimental model of chronic pancreatitis (CP) with diabetes, we investigated pancreatic endocrine function, blood flow, and histopathology in CP induced by repetition of cerulein injection plus water immersion stress in rats. CP rats were treated with water immersion stress for 5 hr and two intraperitoneal injections of 20μg/kg body weight of cerulein once a week for 16 weeks. In the CP group, pancreatic contents of protein, amylase, elastase, and lipase significantly decreased to 64, 38, 23, and 68% of the control group, respectively. In oral glucose tolerance test (glucose 2 g/kg body wt), blood glucose level in the CP group was 212.1±97.8 mg/dl (mean±sd) at 30 min and was significantly higher than the control group (126.3±15.4 mg/dl) (P<0.05). Two of seven rats in the CP group showed an obvious diabetic pattern with a blood glucose level over 200 mg/dl at 120 min. The basal level of serum insulin in the CP group was 640.1±148.7 pM, significantly lower than in the control group (1133.4±242.0 pM) (P<0.001). However, insulin content in the pancreas was 12.37±1.72 nmol/pancreas and was preserved compared with the control group (10.24±1.94 nmol/pancreas). In CP rats, winding and dilatation of surface blood vessels and gland atrophy were evident. Marked fibrosis, fatty changes, and destruction of lobular architecture were also demonstrated microscopically, although the structure of each pancreatic islet was preserved and each islet was fully stained with anti-insulin antibody. In the CP group, pancreatic blood flow by the hydrogen gas-clearance method was 197.6±33.0 ml/min/100 g, which was significantly less than the control group (276.2±19.1 ml/min/100 g) (P<0.001). Thus, we conclude that the CP model induced by cerulein plus stress is a new CP model with diabetes in rats, in which the glucose tolerance was impaired without loss of insulin reserve.

Protective effects of gabexate mesilate on acute pancreatitis induced by tacrolimus (FK-506) in rats in which the pancreas was stimulated by caerulein

We investigated the acute effects of the immunosuppressive agent, tacrolimus (FK-506), on the exocrine pancreas, in rats with or without stimulation of the pancreas, in rats with or without stimulation of the pancreas, and evaluated the protective effects exerted by gabexate mesilate (FOY). While an intravenous injection of FK-506 did not change serum amylase levels during the 5-h observation period, this agent increased pancreatic amylase and protein content, and decreased the content of pancreatic DNA. Histologically, we observed intra-acinar vacuolization and individual cell necrosis. When the pancreas was stimulated by two intraperitoneal injections of caerulein (5 μg/kg) at 1-h intervals, however, which treatment did not induce any evident pancreatic change, FK-506 significantly increased serum amylase, pancreatic wet weight, and pancreatic amylase and protein, and decreased pancreatic DNA. Histologically, there were significant dose-related differences in the severity of intra-acinar vacuolization, interstitial edema, neutrophil infiltration, individual cell necrosis, and hemorrhage. Levels of intrapancreatic elastase were elevated and local pancreatic blood flow was reduced. Treatment with FOY improved the FK-506-induced acute pancreatitis, but did not increase the pancreatic blood flow. These findings indicate that FK-506 enhances abnormal pancreatic enzyme secretion and suggest that therapeutic doses of this agent can induce acute pancreatitis when the pancreas is stimulated. A protease inhibitor may protect the exocrine pancreas in patients who receive FK-506 after organ transplantation.

Morphological study of pancreatic endocrine in an experimental chronic pancreatitis with diabetes induced by stress and cerulein.

The purpose of this study was to investigate the morphological changes in the islets observed in a new chronic pancreatitis model with diabetes induced by repetition of cerulein injection plus water-immersion stress in rats. The rats of this model were treated with water-immersion stress for 5 h and two intraperitoneal injections of 20 micrograms/kg body weight of cerulein once a week for 16 weeks. In the stress and cerulein group, 62% of the islets exhibited infiltration of mononucleated cells, and/or peri- and intrainsular fibrosis. On immunohistochemical study, some islets showed reduced density of the insulin immunoreactivity. The glucagon-producing cells decreased in number. With electron microscopy, various endocrine changes were observed, mainly in the B cells. The changes included scattered debris damage with reduction of secretary granules, and vesiculation of the endoplasmic reticulum. Numerous fibroblasts clustered around the islets, and proliferating collagen fibers invaded the islets. The microvascular changes consisted of bleeding and damage to the endothels. In the pancreas treated with stress alone or cerulein alone, significant endocrine damage was not observed. In conclusion, chronic repetitive treatment with stress and cerulein, together with poor islet circulation due to fibrosis and vascular changes, resulted in the endocrine cellular damage.

Acute pancreatitis induced by hypercalcaemia associated with adult T‐cell leukaemia: A case report

A 44 year old Japanese woman with adult T‐cell leukaemia (ATL) was admitted to Kyushu University hospital to receive a course of α‐interferon treatment. She experienced a sudden onset of hypercalcaemia and epigastric pain associated with an increase in the level of pancreatic enzymes. Her serum parathyroid hormone related protein level was above normal although her high sensitive PTH level was within the normal range. Ultrasonography and computed tomography (CT) of the abdomen showed enlargement of the pancreas with indistinct margins and massive accumulation of extrapancreatic fluid. Cullens sign was observed. A few days after the onset of acute pancreatitis, the serum amylase level increased to 3400 IU/L, and the serum calcium level fell to 4.2 mg/dL from 13.3 mg/dL. Her fasting blood glucose level increased to 242 mg/dL. Although the first episode of pancreatitis appeared to respond to treatment, she experienced a second episode of pancreatitis accompanied by an elevation of the serum calcium level. These findings suggest that acute pancreatitis was caused by hypercalcaemia associated with ATL.

High plasma cholecystokinin response following ingestion of test meal by patients with non-insulin dependent diabetes mellitus.

Postprandial responses of plasma cholecystokinin (CCK) in patients with non-insulin dependent diabetes mellitus (NIDDM) were studied with a CCK specific radioimmunoassay. After the ingestion of a liquid test meal, plasma CCK levels increased from the basal level of 9.8 +/- 1.1 pg/ml to a peak of 19.4 +/- 1.8 pg/ml at 20 min in healthy subjects (n = 10). The ingestion of a test meal in patients with NIDDM (n = 10) resulted in a significantly greater increase of plasma CCK than in healthy subjects and a significant increase of plasma CCK from a basal level of 14.2 +/- 4.4 pg/ml to a peak of 47.4 +/- 12.4 pg/ml at 10 min.

Acute pancreatitis induced by cyclosporin A under stimulation of pancreas by Caerulein

Our purpose was to investigate enzymatically and morphologically the acute effect of the immunosuppressive agent cyclosporin A (CsA) on the exocrine pancreas of rats. The intravenous injection of CsA 10 and 20 mg/kg body weight (BW) increased the content of pancreatic amylase and protein and decreased the content of pancreatic DNA. Histologically, we observed intraacinar vacuolization and individual cell necrosis. Under stimulation of the pancreas by two intraperitoneal injections of caerulein 5 μg/kg BW at 1-h intervals (which did not induce any evident change in the pancreas), CsA induced a significant increase in serum amylase and in pancreatic wet weight in a dose-dependent manner. CsA at doses of 10 and 20 mg/kg BW produced a significant increase in the content of pancreatic amylase and protein. Macroscopically, we observed marked pancreatic edema, venous dilatation, and patchy hemorrhage. Histologically, there were significant differences in the seventy of intra-acinar vacuolization, interstitial edema, neutrophil infiltration, individual cell necrosis, and hemorrhage, severity of which was dose dependent. Pancreatic ductal erosion was particularly marked following treatment with CsA 20 mg/kg BW. These findings indicate that CsA accelerates abnormal pancreatic enzyme secretion and suggest that the therapeutically recommended doses of CsA can induce acute pancreatitis under stimulation of the pancreas.

Effect of irsogladine on gap junctions in cerulein-induced acute pancreatitis in rats

The capacity for intercellular communication (IC) via gap junctions is found in normal pancreatic acinar cells. The major role of IC is considered to be the maintenance of tissue homeostasis and the regulation of signal transmissions. Up to now, the participation of IC via gap junctions in acute pancreatitis has not been reported. We investigated the role of IC in cerulein (Cn)-induced acute pancreatitis in rats using irsogladine, an enhancer of IC via gap junction. Acute edematous pancreatitis was induced in rats by two intraperitoneal injections of 40 μg/kg Cn. Rats received various doses (25, 50, or 100 mg/kg body weight) of irsogladine orally, 15 and 2 h before the first Cn injection. The normal control group received only vehicle. The severity of pancreatitis was evaluated enzymatically and histologically 5 h after the first Cn injection. In Cn-induced acute pancreatitis, irsogladine significantly lowered the serum amylase level, the pancreatic wet weight, and the pancreatic amylase and DNA contents, in a dose-dependent manner. Particularly, the amylase content improved to the level of the normal controls. Histologically, the severity of pancreatitis was reduced significantly by treatment with irsogladine and no discernible vacuolization was seen in the group with 100 mg/kg irsogladine treatment. By immunofluorostaining pancreata with anti-connexin 32 (Cx32; a gap junction protein) antibody, we found that pancreatic acini were diffusely positive for Cx32 in the control group, but the number of Cx32-positive grains decreased markedly, to 19%, in the pancreatitis group. With 100 mg/kg irsogladine treatment, the number of Cx32 grains recovered to 70% of the normal control value. These findings indicate that IC via gap junction is disturbed in Cn-induced pancreatitis, which may result in the breakdown of tissue homeostasis and the progression of acute pancreatitis.