icatibant and Pancreatitis

The role of bradykinin (BK) receptors in activating and sensitizing peripheral nociceptors is well known. Recently, we showed that spinal dynorphin was pronociceptive through direct or indirect BK receptor activation. Here, we explored the potential role of BK receptors in pain associated with persistent pancreatitis in rats.. Experimental pancreatitis and abdominal hypersensitivity were induced by intravenous administrations of dibutyltin dichloride (DBTC). [des-Arg-Leu]BK (B1 antagonist) and HOE 140 (B2 antagonist) were given by intraperitoneal or intrathecal injection. Dynorphin antiserum was given intrathecally. Reverse transcription-polymerase chain reaction was used to detect spinal mRNA for BK receptors.. Dibutyltin dichloride-induced pancreatitis upregulated B1 and B2 mRNA in the thoracic dorsal root ganglion and B2, but not B1, in the pancreas. No changes in spinal B1 or B2 mRNA were observed. Intraperitoneal or intrathecal administration of HOE 140 dose dependently abolished DBTC-induced abdominal hypersensitivity, whereas [des-Arg-Leu]BK was without effect by either route of administration. Antiserum to dynorphin (intrathecal) abolished DBTC-induced hypersensitivity.. These results suggest that blockade of peripheral or spinal BK B2 receptors may be an effective approach for diminishing pain associated with pancreatitis. Moreover, it is suggested that spinal dynorphin may maintain pancreatitis pain through direct or indirect activation of BK B2 receptors in the spinal cord.

Topics: Abdominal Pain; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Bradykinin B1 Receptor Antagonists; Bradykinin B2 Receptor Antagonists; Dynorphins; Ganglia, Spinal; Gene Expression; Immune Sera; Injections, Intraperitoneal; Injections, Intravenous; Injections, Spinal; Male; Organotin Compounds; Pain; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Receptor, Bradykinin B1; Receptor, Bradykinin B2; Reverse Transcriptase Polymerase Chain Reaction; Spinal Cord

Secretory phospholipases A2 (sPLA2s) induce acute pancreatitis when injected into the common bile duct of rats. Substance P via neurokinin 1 (NK-1) receptors and bradykinin via B2 receptors are described to play important roles in the pathophysiology of acute pancreatitis. This study was undertaken to evaluate the role of substance P and bradykinin in the sPLA2-induced pancreatitis.. Rats were submitted to the common bile duct injection of sPLA2 obtained from Naja mocambique mocambique venom at 300 microg/kg. At 4 hours thereafter, measurement of pancreatic plasma extravasation, pancreatic and lung myeloperoxidase (MPO), serum amylase, and serum tumor necrosis factor alpha levels were evaluated.. Injection of sPLA2 significantly increased all parameters evaluated. Pretreatment with either the NK-1 receptor antagonist SR140333 or the B2 receptor antagonist icatibant largely reduced the increased pancreatic plasma extravasation and circulating levels of tumor necrosis factor alpha. Both treatments partly reduced the MPO levels in the pancreas, whereas in the lungs, icatibant was more efficient to reduce the increased MPO levels. In addition, icatibant largely reduced the serum levels of amylase, whereas SR140333 had no significant effect.. We concluded that NK-1 and B2 receptors can regulate important steps in the local and remote inflammation during acute pancreatitis induced by sPLA2.

Topics: Acute Disease; Amylases; Animals; Bradykinin; Bradykinin B2 Receptor Antagonists; Disease Models, Animal; Lung; Male; Neurokinin-1 Receptor Antagonists; Pancreas; Pancreatitis; Peroxidase; Phospholipases A2, Secretory; Piperidines; Pneumonia; Quinuclidines; Rats; Rats, Wistar; Receptor, Bradykinin B2; Receptors, Neurokinin-1; Substance P; Tumor Necrosis Factor-alpha

1 Kinin B(2) receptor antagonists or tissue kallikrein (t-KK) inhibitors prevent oedema formation and associated sequelae in caerulein-induced pancreatitis in the rat. We have now further investigated the mechanism of kinin generation in the pancreas. 2 Kinins were elevated in the pancreatic tissue already before oedema formation became manifest. Peak values (421+/-59 pmol g(-1) dry wt) were reached at 45 min and remained elevated for at least 2 h; a second increase was observed at 24 h. Pretreatment with the B(2) receptor antagonist icatibant abolished kinin formation, while post-treatment was ineffective. 3 Total kininogen levels were very low in the pancreas of controls, but increased 75-fold during acute pancreatitis. This increase was absent in rats that were pretreated with icatibant. 4 During pancreatitis, t-KK-like and plasma kallikrein (p-KK)-like activity in the pancreas, as well as trypsinogen activation peptide (TAP) increased significantly. Icatibant pretreatment further augmented t-KK about 100-fold, while p-KK was significantly attenuated; TAP levels remained unaffected. 5 Endogenous protease inhibitors (alpha(1)-antitrypsin, alpha(2)-macroglobulin) were low in normal tissues, but increased 45- and four-fold, respectively, during pancreatitis. This increase was abolished when oedema formation was prevented by icatibant. 6 In summary, oedema formation is initiated by t-KK; the ensuing plasma protein extravasation supplies further kininogen and active p-KK to the tissue. Concomitantly, endogenous protease inhibitors in the oedema fluid inhibit up to 99% of active t-KK. Our data thus suggest a complex interaction between kinin action and kinin generation involving positive and negative feedback actions of the inflammatory oedema.

Topics: Acute Disease; alpha 1-Antitrypsin; alpha-Macroglobulins; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Ceruletide; Edema; Enzyme Activation; Female; Kininogens; Kinins; Pancreas; Pancreatitis; Plasma Kallikrein; Rats; Rats, Sprague-Dawley; Receptors, Cell Surface; Serine Proteinase Inhibitors; Tissue Kallikreins; Trypsinogen

1. The involvement of bradykinin (BK) B(2) receptor in acute pancreatitis induced by pancreaticobiliary duct ligation was investigated in rats. 2. The activities of amylase and lipase in the serum, the water content of the pancreas, and vacuolization of the acinar cells were significantly increased 2 h after obstruction of the duct in Sprague-Dawley rats. 3. Elevated serum amylase activity, increased pancreatic oedema, and damage of the pancreatic tissue were significantly less marked in plasma kininogen-deficient, B/N-Katholiek rats than in the normal strain, B/N-Kitasato rats 2 h after the ligation. 4. Obstruction of the pancreaticobiliary duct augmented the level of (1-5)-BK (Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)), a stable BK metabolite, in the blood from 73.0+/-21.7 pg ml(-1) at 0 h to 149.8+/-38.0 pg ml(-1) at 2 h after the induction of pancreatitis in SD rats. 5. Administration of a BK B(2) receptor antagonist, FR173657 (100 mg kg(-1), p.o.) or Hoe140 (100 nmol kg(-1), s.c.), reduced the elevation of amylase and lipase activities in the serum and of pancreatic water content in a dose-dependent manner. The effective attenuation of oedema formation and vacuolization by the antagonists was also confirmed light-microscopically. In contrast, treatment with gabexate mesilate or indomethacin did not cause significant suppression of the pancreatitis. 6. These findings suggest a possible involvement of kinin B(2) receptor in the present pancreatitis model. Furthermore, they point to the potential usefulness of the B(2) receptor in clinical acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bile Ducts; Bradykinin; Bradykinin Receptor Antagonists; Dose-Response Relationship, Drug; Edema; Kininogens; Lipase; Male; Pancreas; Pancreatic Ducts; Pancreatitis; Peptide Fragments; Quinolines; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; Receptor, Bradykinin B2; Water

To investigate the impact of the long-acting bradykinin B2 receptor antagonist HOE 140 (Icatibant) on survival time in a model of severe porcine pancreatitis.. Randomized, controlled intervention trial.. Thirty domestic pigs of either gender anesthetized by intravenous application of piritramide, midazolam, and pancuronium and mechanically ventilated.. Pancreatitis was induced by an injection of sodium taurocholate (5%, 1 mL/kg body weight [BW]) and enterokinase (10 U/kg BW). Control animals (group 1, n = 10) underwent the spontaneous course of the disease. In two treatment groups, Icatibant was administered either in a low (100 nmol/kg BW; group 2, n = 10) or in a high dosage (5000 nmol/kg BW; group 3, n = 10).. Mean survival time was significantly prolonged by Icatibant (controls, 6.6 hrs; group 2, 9.8 hrs; p = .022; group 3, 10.9 hrs; p = .007). Six hours postinduction, the decline of total peripheral resistance (52% of baseline) and cardiac index (92% of baseline) in controls was significantly improved by Icatibant, both in the low (16% and 44%; p < .05) and high (6% and 45%; p < .05) dosage. The concentrations of free, nonreceptor-bound kinin in plasma 6 hrs postinduction were significantly lower in controls than in groups 2 and 3 animals (111+/-50 vs. 208+/-40 and 237+/-52 fmol/mL, respectively). Six hours postinduction, the pretreatment with Icatibant was associated with significantly higher plasma concentrations of phospholipase A2 (controls, +1194%; group 2, +2000%; group 3, +2285% of baseline values) and interleukin-1 receptor antagonist (controls, 1900+/-800; group 2, 3100+/-800; group 3, 3600+/-800 pg/mL). In contrast, the increase of urinary trypsinogen activation peptides indicating local pancreatic damage (589+/-114 nmol/L in controls) was substantially attenuated by pretreatment with Icatibant (group 2, 467+/-102, NS; 352+/-91 nmol/L in group 3; p = .022 vs. controls). Systemic inflammatory reactions, however, as quantified by C-reactive protein and the extracellularly discharged neutrophil cytosolic inhibitor leukocyte neutral proteinase inhibitor were not influenced by the bradykinin B2-receptor antagonist.. Pretreatment with the bradykinin B2 receptor antagonist Icatibant resulted in prolonged survival time and in delayed impairment of major macrocirculatory and pulmonary variables. Icatibant resulted in elevated concentrations of free, circulating kinin. This was associated with increased concentrations of phospholipase A2 and interleukin-1 receptor antagonist, suggesting that circulating kinins strengthen the activation of some mediator cascades, the association of which with the kinin metabolism requires further experimental clarification. Other variables indicating a systemic inflammatory response (C-reactive protein, leukocyte neutral proteinase inhibitor) remained unaffected by Icatibant. Bradykinin antagonism distinctly ameliorated the local pancreatic damage, indicated by increased urinary concentrations of trypsinogen activation peptides. It is concluded that the kinin metabolism plays an important role in the pathophysiology of systemic complications after severe experimental pancreatitis.

Topics: Acute Disease; Adrenergic beta-Antagonists; Animals; Bradykinin; Bradykinin Receptor Antagonists; C-Reactive Protein; Disease Models, Animal; Drug Evaluation, Preclinical; Hemodynamics; Kinins; Pancreatitis; Peptides; Phospholipases A; Phospholipases A2; Random Allocation; Receptor, Bradykinin B2; Receptors, Bradykinin; Swine; Systemic Inflammatory Response Syndrome; Time Factors

It was determined earlier that inhibition of the action of endogenous kinins by the bradykinin B2 antagonist, icatibant (Hoe-140; D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]-bradykinin), prevents pancreatic oedema formation during caerulein-induced acute pancreatitis, and simultaneously improves the egress of activated pancreatic enzymes from the pancreas. We have now investigated whether inhibition of increases in vascular permeability by another approach, i.e., pretreatment with dexamethasone, would have comparable effects. In addition, preliminary data are presented on the effects of the selective low molecular weight inhibitor of tissue kallikrein, H-(4-Cl)-D-Phe-1Nal-(3-aminopropyl)-guanidine (CH-2856). Icatibant abolished plasma extravasation into the pancreatic tissue and prevented the development of hypovolaemia. Caerulein-induced increases of amylase activity in the pancreas were significantly reduced by icatibant, while amylase activity in blood was augmented. Inhibition of kinin generation by CH-2856 had similar effects, as oedema formation was inhibited and enzyme activities were reduced in the pancreas and augmented in the blood serum. Dexamethasone completely abolished oedema formation, but only partially inhibited the development of hypovolaemia and haemoconcentration. Amylase activities in the pancreas and in blood remained completely unaffected by dexamethasone. The results suggest that retention of activated enzymes in the pancreatic tissue during acute pancreatitis involves a B2 receptor-mediated, but glucocorticoid-insensitive mechanism.

Topics: Acute Disease; Amylases; Animals; Bradykinin; Capillary Permeability; Dexamethasone; Edema; Female; Kinins; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley

The effect of B2 receptor bradykinin antagonist icatibant on postcapillary leukostasis, microcirculatory stasis, and tissue necrosis was studied in acute pancreatitis. In rats, pancreatitis was induced by intraductal injection of sodium taurocholate (ST), intravenous caerulein and intraductal infusion of glucodeoxycholic acid (GDOC), or intravenous caerulein infusion alone. Intravital pancreatic microcirculation was observed. Icatibant or vehicle was given 30 min before induction of pancreatitis. In ST pancreatitis, the number of perfused capillaries increased in icatibant-pretreated rats (77% vs. 0% for controls, P < 0.001). Capillary flow was preserved in icatibant-treated rats; total stasis was observed in controls. Mean venular leukocyte adherence decreased in icatibant-treated rats (26% vs. 74% for controls, P < 0.001), and median histopathologic score was reduced (icatibant vs. controls, 5.0 vs. 12 points, respectively; P < 0.01). Kinase II inhibitor captopril or exogenous bradykinin in addition to an otherwise effective dosage of icatibant resulted in microcirculatory stasis, extensive venular leukocyte adherence, and severe histological damage. With a 100 times greater icatibant dosage, this adverse effect was compensated. The beneficial effects of icatibant were also observed in intermediate pancreatitis (caerulein + GDOC). In ST and intermediate pancreatitis, icatibant preserved microcirculation, reduced venular leukocyte adherence, and prevented pancreatic tissue damage. B2 receptor bradykinin-mediated postcapillary leukostasis plays an important role in the pathogenesis of severe forms of acute pancreatitis.

Topics: Acute Disease; Animals; Arterioles; Bradykinin; Bradykinin Receptor Antagonists; Capillaries; Cell Adhesion; Ceruletide; Edema; Female; Hemorrhage; Leukocytes; Microcirculation; Pancreas; Pancreatitis; Rats; Rats, Inbred Lew; Receptor, Bradykinin B2; Regional Blood Flow; Taurocholic Acid; Time Factors; Vasoconstriction; Venules

One of the vasoactive peptides that has been implicated in the progression from edematous to necrotizing pancreatitis is bradykinin. We have investigated the effect of bradykinin administration and bradykinin inhibition on an edematous model of acute pancreatitis in rats (10 micrograms/kg/h of caerulein i.v.). Within six hours i.v. bradykinin reduced circulating serum amylase levels significantly but neither affected tissue edema nor morphology. A bradykinin antagonist (HOE-140), on the other hand, reduced pancreatic edema by 70% and converted edematous pancreatitis into a hemorrhagic and necrotizing variety of the disease. In further experiments we determined the time course and the minimal dosage required for the induction of this severe and non-invasive disease variety. A single dose of caerulein (40 micrograms/kg i.p.) together with a single administration of the bradykinin antagonist HOE-140 (100 micrograms/kg s.c.) consistently resulted in hemorrhagic necrosis of the pancreas within six hours. We conclude that this simple protocol allows for the non-invasive induction of a vascular model of necrotizing pancreatitis and appears ideally suited to study the development of this severe form of the disease.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Ceruletide; Disease Models, Animal; Edema; Hemorrhage; Male; Necrosis; Pancreatitis; Rats; Rats, Wistar

The effect of a potent and long-acting bradykinin B2-receptor antagonist (HOE140) on acute pancreatitis induced by retrograde infusion of trypsin and taurocholate into the pancreatic duct was studied in rats. HOE140 was administered subcutaneously immediately before and 3 h after the induction of pancreatitis and the systemic blood pressure, ascites volume, serum amylase, 24-h survival rate, and pathology of the pancreas were evaluated. Plasma concentrations of bradykinin increased significantly 15 min after the induction of pancreatitis and decreased to basal levels at 90 min. HOE140 (0.1 mg/kg) alleviated hypotension developing immediately after the induction of pancreatitis and reduced the ascites volume. The 24-h survival rate in rats treated with 0.1 mg/kg HOE140 (70.3%) was significantly higher than that in controls (35.6%). Treatment with 0.01, 0.3, 1.0, and 3.0 mg/kg of HOE140, however, had no beneficial effect on the survival rate. Ascites volume, serum amylase, and pathology of the pancreas at 24 h were not improved by treatment with HOE140. These data suggest that HOE140 may improve the survival rate by maintaining hemodynamics in the early stage of experimental acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Ascites; Blood Pressure; Bradykinin; Bradykinin Receptor Antagonists; Hematocrit; Kinetics; Male; Pancreas; Pancreatitis; Rats; Rats, Wistar; Taurocholic Acid; Trypsin

Bradykinin and beta-endorphin increases during acute pancreatitis are thought to contribute to the development of hypotension and myocardial depression in acute pancreatitis. beta-Endorphin release is mediated by trypsin-like enzymes and bradykinin from the pituitary gland. This study was undertaken to investigate the effect of a long-acting bradykinin receptor antagonist on bradykinin and beta-endorphin release and on hemodynamic changes during acute pancreatitis. Pancreatitis was induced by the injection of autologous bile mixed with trypsin into the main pancreatic duct after ligation of the accessory duct. Serum bradykinin and plasma beta-endorphin levels and cardiovascular function were measured. Twelve dogs (control group) were given 10 ml/kg/h of lactate Ringer's solution intravenously beginning 1 h before the induction of pancreatitis and continuing throughout the experiments. Six dogs received an intravenous infusion of 0.6 mg/kg/h of a new bradykinin receptor antagonist, HOE 140, D-Arg-[Hyp3, Thi5, D-Tic, Oic8]-bradykinin, in lactate Ringer's solution soon after the induction of pancreatitis. Six of twelve dogs in the control group, and none of the six dogs in the bradykinin receptor antagonist group, died during the experiments. Serum bradykinin levels in both groups increased until 1 h after the induction of pancreatitis, but thereafter the levels in the bradykinin receptor antagonist group decreased gradually until 5 h after induction, and levels were significantly lower than those in the control group (p < 0.05). Plasma beta-endorphin levels in the control group increased significantly, to 291.8 pg/ml (+/- 6.6 SEM) 5 h after the induction of pancreatitis, from the mean levels of 47.8 pg/ml before the induction of pancreatitis, while the mean beta-endorphin level in the bradykinin receptor antagonist group did not increase after the induction of pancreatitis. Infusion of the bradykinin receptor antagonist improved survival rates, hypotension, myocardial depression, and plasma lactate, suggesting that the bradykinin receptor antagonist inhibited the release of bradykinin and beta-endorphin, which contributed to the clinical improvement.

Topics: Acute Disease; Adrenergic beta-Antagonists; Animals; beta-Endorphin; Bradykinin; Bradykinin Receptor Antagonists; Dogs; Hemodynamics; Male; Pancreatitis

Little is known about the pathophysiological factors that determine the clinical severity of acute pancreatitis. Because impairment of pancreatic circulation and oxygenation is associated with greater disease severity and morphological damage in experimental pancreatitis it has been suggested that various vasoactive mediators might participate in the progression from the oedematous to the necrotising variety of the disease. This study used an animal model of acute pancreatitis induced by intravenous caeruleint (10 micrograms/kg/h for up to six hours), which does not entail either haemorrhage or significant necrosis of the pancreas. This study considered whether the administration or the inhibition of either nitric oxide, bradykinin, or adrenergic mediators can convert this mild variety into haemorrhagic and necrotising pancreatitis. Neither nitric oxide nor catecholamines were involved in the progression from oedematous to haemorrhagic pancreatitis. Their substitution, activation, and inhibition all failed to change the severity of the disease process. Bradykinin alone seemed to be critically involved in the pathogenesis of pancreatic haemorrhage and necrosis. However, the inhibition of bradykinin and not its activation or substitution increased the severity of the disease.

Topics: Acute Disease; Animals; Arginine; Bradykinin; Catecholamines; Ceruletide; Edema; Labetalol; Male; Microcirculation; Microscopy, Electron, Scanning; Necrosis; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitroglycerin; Pancreas; Pancreatitis; Phenylephrine; Rats; Rats, Wistar

The effect of bradykinin on nitric oxide generation and eicosanoid production in the early stage of an experimental model of acute necrotizing pancreatitis induced by sodium taurocholate has been evaluated. We have compared the effect of administering a long-acting bradykinin antagonist, HOE 140, and an inhibitor of nitric oxide synthase, NG-nitro-L-arginine methyl esther L-NAME) on pancreatic prostanoid synthesis. Plasma lipase levels were increased after acute pancreatitis induction, and reduced after HOE 140 or L-NAME administration. Nitric oxide production and thromboxane B2 levels were increased after pancreatitis induction and the increases were reduced by L-NAME or HOE 140 administration. In contrast, increased prostacyclin production, reflected as 6-keto-PGF1 alpha levels, was not modified by L-NAME or HOE 140. Bradykinin seems to be involved in nitric oxide and thromboxane synthesis during the initial phases of acute necrohemorrhagic pancreatitis.

Topics: Acute Disease; Animals; Arginine; Bradykinin; Lipase; Male; Necrosis; NG-Nitroarginine Methyl Ester; Nitric Oxide; Pancreas; Pancreatitis; Rats; Rats, Wistar; Taurocholic Acid; Thromboxane B2

It has been found earlier that the bradykinin antagonist, icatibant (Hoe 140), prevents the pancreatic oedema and the ensuing hypotension and haemoconcentration, and facilitates the removal of activated enzymes form the tissue during caerulein-induced acute pancreatitis. For a potential therapeutic use of the compound in clinical situations it is essential to investigate whether the associated increase in enzyme activities in the blood serum has any adverse effects on the pancreas itself or on other organs. Normal amylase secretion into the biliopancreatic duct stimulated by a low dose of caerulein (0.4 nmol kg-1 h-1, i.v.) was not affect by icatibant (100 nmol kg-1, s.c.) Acute pancreatitis, induced by a high dose of caerulein (4 nmol kg-1 h-1 for 2 h, i.v.), resulted in elevations in the activities of amylase and lipase in the pancreatic tissue and in the blood serum lasting for at least 4 h after the end of the caerulein infusion. While the rise in enzyme activities in the blood serum was augmented in icatibant-treated rats only at the end of the caerulein-infusion, the enzyme accumulation in the pancreas was significantly reduced by icatibant for at least 4 h after the end of the caerulein infusion. The secretion of amylase and lipase into the biliopancreatic duct was significantly increased only during the first 20 min of acute pancreatitis; in rats pre-treated with icatibant, no significant increase could be observed. Twenty-four hours after induction of pancreatitis, a low-dose caerulein stimulation of the exocrine function of the pancreas led to a reduced but sustained secretion of amylase regardless of whether the animals had received icatibant or not. During the first 45 min of pancreatitis, blood glucose concentrations were significantly reduced, but returned to values not different from those obtained in saline-infused controls. This effect was not affected by icatibant. No changes in the response to an i.v. glucose tolerance test were found on the day after induction of acute pancreatitis. The serum activities of glutamic pyruvic transaminase and gamma-glutamyl transpeptidase determined up to 24 h after induction of pancreatitis were not different from saline controls. icatibant had no effect on the activities of these enzymes. It is concluded that during caerulein-induced acute pancreatitis normal exocrine secretion of pancreatic enzymes into the pancreatic duct ceases almost immediately. Pre-treatment with icatibant significantly reduces th

Topics: Acute Disease; Animals; Blood Glucose; Bradykinin; Ceruletide; Female; Lipase; Liver; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley

1. In a previous investigation, Hoe 140, a specific and potent bradykinin B2 receptor antagonist, prevented the pancreatic oedema and the hypotension observed during acute experimental pancreatitis; however, it augmented the associated rises in the serum activities of pancreatic enzymes. Therefore, we have now investigated the consequences of the pancreatic oedema for the fate of activated enzymes released into the tissue during the course of acute pancreatitis. 2. Acute oedematous pancreatitis was induced in rats, pretreated with captopril (50 mumol kg-1, i.p.), by hyperstimulation of the exocrine function of the pancreas with the cholecystokinin analogue, caerulein (4 nmol kg-1 h-1, i.v.), for up to 120 min. 3. Pancreatic oedema began to develop 10 min after the start of the caerulein infusion, reached a maximum within about 45 min, and then declined slightly. The development of the oedema parallelled the second phase of the caerulein-induced fall in blood pressure found in earlier experiments. No further extravasation of plasma proteins occurred during the 2nd hour of the caerulein infusion. The oedema formation was completely blocked in animals pretreated with the bradykinin receptor antagonist, Hoe 140 (100 nmol kg-1, s.c.). Pretreatment with aprotinin or soy bean trypsin inhibitor did not result in a significant inhibition of the oedema. 4. The haematocrit of animals with experimental pancreatitis showed a pronounced increase which started 10 min after the start of the caerulein infusion and reached maximal values at 60 min. The changes in haematocrit showed a reduction in total blood volume of 28% due to a 48% loss of plasma. This effect was completely blocked by Hoe 140. 5. In rats with caerulein-induced pancreatitis, there was a time-dependent increase in the activities of amylase and lipase in blood serum as well as in the pancreas. Pretreatment with Hoe 140 greatly augmented the caerulein-induced rise in enzyme activities in blood serum but potently attenuated it in the pancreas. The activities of trypsin in both the blood serum and the pancreas were below or near the limit of detection in all experimental groups.6. It is concluded that the second phase of hypotension in this model of acute pancreatitis is due to the liberation of kinins which cause a massive loss of blood plasma into the pancreas and into the retroperitoneal space. Activated enzymes are trapped in the pancreas, at least in part, by the oedema of the gland. Treatment with Hoe 1

Topics: Acute Disease; Animals; Bradykinin; Edema; Female; Hematocrit; Hypotension; Pancreas; Pancreatitis; Protease Inhibitors; Rats; Rats, Sprague-Dawley

1. The novel bradykinin antagonist, HOE 140, completely blocked the fall in rabbit blood pressure caused, not only by i.v. bradykinin, but also by i.v. kallikrein. This shows that both the effects of exogenously administered bradykinin and those of endogenously released kinins are antagonized by HOE 140. 2. Acute pancreatitis was induced in rats by i.v. infusion of the cholecystokinin analogue, caerulein. This treatment resulted in massive oedema of the pancreas, increased activities of amylase and lipase in serum and a characteristic, biphasic fall in blood pressure. 3. HOE 140 prevented the caerulein-induced pancreatic oedema and the second phase of hypotension whereas NPC 349, a widely used, but short-acting, bradykinin antagonist did not show a significant inhibition. HOE 140, in contrast to its inhibitory effects on caerulein-induced pancreatic oedema and hypotension, significantly augmented the increases in amylase and lipase activities in serum. 4. It is concluded that in this model of acute pancreatitis, the release of kinins induces pancreatic oedema and hypotension. Prevention by HOE 140 of the kinin-induced oedema allows the pancreatic enzymes to leave the tissue without hindrance and thus will diminish subsequent pathological events. It is suggested that the results obtained with the highly potent and long-acting bradykinin antagonist, HOE 140, provide a pharmacological basis for a clinical trial in acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blood Pressure; Bradykinin; Ceruletide; Female; Kallikreins; Lipase; Oligopeptides; Pancreatitis; Rats; Rats, Sprague-Dawley