Induction of acute-phase reactive substances during open-heart surgery and efficacy of ulinastatin. Inhibiting cytokines and postoperative organ injury

OBJECTIVE

A systemic inflammatory response after open-heart surgery using cardiopulmonary bypass may be responsible for postoperative organ dysfunction. Ulinastatin, a protease inhibitor, plays an important role in host defense under periods of stress.

METHODS

We studied the efficacy of ulinastatin on changes in acute-phase reactive substances during and after open-heart surgery. Patients undergoing open-heart surgery were divided into an ulinastatin group (Group U) and a control group (Group C). In Group U, we introduced 600,000 units of ulinastatin into a priming solution for cardiopulmonary bypass, 300,000 units into a cardiopulmonary bypass circuit at the removal of aortic cross-clamping, and 300,000 units a day for 5 days following surgery.

RESULTS

Immediately after cardiopulmonary bypass, alpha 1-antitrypsin levels decreased significantly in both groups, and increased significantly on the second day after surgery. Ulinastatin levels decreased after cardiopulmonary bypass in Group C. Significantly high levels of ulinastatin were obtained in Group U. Interleukin-6, interleukin-8, and polymorphonuclear elastase were markedly induced, and high levels of plasma concentration continued for several days after surgery. At all sample points, these concentrations in Group U tended to be lower than those in Group C. A significantly positive correlation was seen between the maximum levels of interleukin-8 and polymorphonuclear elastase, but these cytokine and polymorphonuclear elastase levels did not correlate with parameters such as the duration of anesthesia, surgery, cardiopulmonary bypass, or aortic cross-clamping.

CONCLUSIONS

Our study suggests that high-dose ulinastatin administration to maintain a sufficient concentration of circulating protease inhibitors may suppress overinduction of cytokines and polymorphonuclear elastase in open-heart surgery.

Milk-borne insulin with trypsin inhibitor in milk induces pancreatic amylase development at the onset of weaning in rats

BACKGROUND

The physiologic significance of milk-borne hormones and growth factors for internal organs of suckling animals is poorly understood. In this study the significance of milk-borne insulin was evaluated, as well as its combination with trypsin inhibitor, and its role in the development of pancreatic digestive capacity at the time of weaning was investigated.

METHODS

Experiments were performed using insulin-deficient milk formula (standard formula), insulin (20 ng/ml) formula, or insulin with trypsin inhibitor (1 U/ml) formula by a rat artificial-rearing technique.

RESULTS

In 17-day-old rats administered standard formula, the plasma insulin level was as low as that in 14-day-old rats. When insulin-trypsin inhibitor formula was administered to rat pups, the plasma insulin level was significantly higher than those in rats given standard or insulin formula. In rats artificially reared on standard formula, the usual developmental increases in pancreatic amylase activity and plasma insulin concentration at the beginning of weaning did not occur. Insulin formula elevated the pups' plasma insulin concentration and amylase activity at the onset of weaning but not to the levels observed in mother-reared rats. In rats reared on insulin-trypsin inhibitor formula, the developmental increases in the plasma insulin concentration and amylase activity observed in mother-reared rats were induced.

CONCLUSIONS

The present study demonstrates the necessity of milk-borne insulin for the development of pancreatic amylase during the weaning period.

Oral administration of a synthetic trypsin inhibitor increases pancreatic duct function in CCK-A receptor-deficient rats

The effects of oral administration of a synthetic trypsin inhibitor on bicarbonate secretion were examined in cholecystokinin A (CCK-A) receptor-deficient (OLETF) rats and compared with Wistar rats. Rats were fed chow containing 0.1% trypsin inhibitor for 7 days. Rats were prepared with cannulae draining bile and pancreatic juice separately and with duodenal and extrajugular vein cannulae after 3-day trypsin inhibitor ingestion. Then the animals were maintained in Bollman cages, and the experiments were conducted 4 days after surgery. After 1.5 h of basal secretion with bile-pancreatic juice return, bile-pancreatic juice was diverted for 2 h. The responses of bicarbonate secretion to bile-pancreatic juice diversion were significantly enhanced in rats treated with trypsin inhibitor compared with those given a control diet, whereas responses of fluid and protein secretion were not affected in OLETF rats. The response of protein secretion, but not those of fluid or bicarbonate secretion, was enhanced in Wistar rats by treatment with trypsin inhibitor. Carbonic anhydrase II gene expression was increased by 7-day treatment with trypsin inhibitor only in OLETF rats, and not in Wistar rats.

[Supplement of ulinastatin on renal function after cardiopulmonary bypass]

The effects of Miraclid (ulinastatin) on renal tubular function after open thorax surgery under cardiopulmonary bypass were investigated. On the 3rd day after open thorax surgery, which had lasted more than 127 min under cardiopulmonary bypass, the levels of urinary ulinastatin in the Miraclid group and control (without Miraclid) were 170 IU.mg Cr-1 and 95 IU.mg Cr-1, respectively. In the Miraclid group, 300,000 units.day-1 of Miraclid was administrated for three postoperative days. N-acetyl-beta-d-glucosaminidase in urine as a marker of tubular function rose significantly on the seventh postoperative day in the control group but not in patients with Miraclid group. These data suggested that Miraclid 300,000 units.day-1 was needed to protect renal tubular function and more than that dose was needed to prevent the deterioration of renal function after open thorax surgery after cardiopulmonary bypass lasting more than 127 min.

Single-dose administration of Bowman-Birk inhibitor concentrate in patients with oral leukoplakia

The Bowman-Birk inhibitor (BBI) is a soybean-derived serine protease inhibitor and a potential cancer chemopreventive agent for humans. In this Phase I clinical trial, BBI concentrate was administered as a single oral dose to 24 subjects with oral leukoplakia. Pharmacokinetics of BBI was analyzed, and subjects were monitored clinically for toxic effects. Subjects received between 25 and 800 chymotrypsin inhibitor units (CIU) of the compound in a dose escalation trial. BBI was taken up rapidly, and a metabolic product of BBI was excreted in the urine within 24-48 h. No clinical or laboratory evidence of toxicity was observed in the study. Protease activity was also measured in buccal cells to evaluate usefulness as a biomarker. Single-dose BBI concentrate administered up to 800 CIU was well tolerated and appeared to be nontoxic. Further investigation in Phase II clinical trials is being done.

Evaluation of perioperative administration of methylprednisolone sodium succinate and urinary trypsin inhibitor for prevention of surgical stress

The authors could confirm that the laparoscopy-assisted cholecystectomy (LAC) elicited less postoperative biological responses compared to the ordinary cholecystectomy under laparotomy (OCL), when granulocyte elastase (GE)-alpha1-protease inhibitor complex (GEcomplex), interleukin-6, pancreatic secretory trypsin inhibitor (PSTI) and alpha1-antitrypsin (alpha1-AT) were used as biological response markers. Perioperative administrations of methylprednisolone sodium succinate (MPSL: 10 mg/kg body weigh) or MPSL with urinary trypsin inhibitor (UTI) could suppress such postoperative reactions after OCL down to the levels after LAC, especially immediately after surgery. Preoperative MPSL followed by continuous infusion of UTI for 3 days exerted the most prominent suppressive effects on these markers compared to the effect of the preoperative MPSL alone as well as the preoperative administration of MPSL followed by UTI infusion for only one hour. Bolus administration of MPSL induced no lymphocytopenia. Decreased plasma level of alpha1-AT immediately after operation is thought to be due to consumption in binding to GE as well as other lysosomal enzymes, while production of rapid turn over proteins are still not accelerated in the liver. In early postoperative phase after administration of MPSL, administration of UTI was efficacious to prevent fluctuation of biological response markers. Clinical applications of these drugs might be approved especially for those patients with poor risk.

Aerosolized prolastin suppresses bacterial proliferation in a model of chronic Pseudomonas aeruginosa lung infection

High levels of active neutrophil elastase (HNE) are present in the respiratory secretions of patients with cystic fibrosis (CF). We hypothesized that aerosolized Prolastin (alpha(1)-protease inhibitor or alpha(1)PI, purified from human blood) could suppress airway neutrophil inflammation and accelerate bacterial clearance from the lung in a model of chronic Pseudomonas aeruginosa lung infection. Because human alpha(1)PI effectively inhibits rat as well as human neutrophil elastase (NE) activity in vitro, we choose to test this hypothesis using a rat agar bead model of chronic P. aeruginosa lung infection. In this model, aerosolized Prolastin significantly decreased elastase activity (p < 0.01), lung neutrophil counts (p < 0.01), and bacterial colony counts (p < 0.01). Prolastin had no direct bactericidal effect on P. aeruginosa in vitro. Lung tissue histopathology revealed a marked decrease in lung inflammation in animals treated with Prolastin. These studies indicate that Prolastin can significantly decrease the elastase burden in the chronically infected lung. In addition, not only does Prolastin suppress lung inflammation, but it also markedly decreases P. aeruginosa density in a rat model of chronic P. aeruginosa lung infection. These data suggest that aerosolized alpha(1)PI may represent a useful nonantibiotic adjunct in the treatment and control of infection and inflammation associated with CF lung disease.

Alpha 1-antitrypsin deficiency and the impact of nursing interventions and treatment with intravenous therapy. An overview

The primary function of alpha1-antitrypsin is to protect the alveoli in the lung from harmful destruction from proteolytic enzymes, which prevent optimal elastic recoil of the lungs and destroy the lungs. Insufficient serum levels of alpha1-antitrypsin eventually lead to early onset of emphysema in the third, fourth, or fifth decade of life. Treatment of alpha1-antitrypsin deficiency by intravenous administration of an enzyme inhibitor known as alpha1-proteinase inhibitor, a human-derived blood product, can be administered to help replace the enzymes required to maintain lung function. Early detection, nursing intervention, and clinical management slow the progression of this hereditary disease.

Reducing neutrophil elastase-induced lung injury

The first trial of alpha1-proteinase inhibitor therapy for the prevention of chronic lung disease of prematurity was recently completed. Receipt of four intravenous doses of the medication was associated with a trend towards a reduction in respiratory morbidity. A dose-ranging trial is in progress.

Development and in vitro evaluation of a drug delivery system based on chitosan-EDTA BBI conjugate

In this study a (poly)peptide drug delivery system providing a protective effect towards serine pancreatic proteases was generated. Tablets containing insulin (3.3%), chitosan-EDTA (56.7%), chitosan-EDTA Bowman Birk Inhibitor (= BBI) conjugate (10%) and mannitol (30%) were homogenised in a mortar and compressed to tablets. The protective effect of this dosage form for the incorporated model drug was evaluated in vitro. Tablets were therefore incubated with an artificial intestinal fluid containing trypsin (1350 spectrophotometric BAEE units/ml), chymotrypsin (3.6 BTEE units/ml) and elastase (0.14 succinyl-Ala-Ala-Ala-p-nitroanilide units/ml) for 4.5 h at 37 degrees C. Following analysis of the dosage form demonstrated that 58.6+/-26.8% (mean +/- SD; n = 3) insulin in lateral parts and 44.4+/-12.4% (mean +/- SD: n = 3) insulin in inner parts of the swollen carrier-matrix were degraded, whereas insulin was completely metabolised in lateral parts and by 90.3+/-12.5% (mean +/- SD: n = 3) in inner parts of tablets without the chitosan-EDTA BBI conjugate. As chitosan-EDTA also provides a protective effect towards zinc-dependent proteases, the delivery system described in this study should therefore guarantee a protection towards the most abundant intestinal proteases. It might be a promising formulation for the peroral administration of peptide and protein drugs.

Effect of methylcarbonylmethyl 2(S)-[4-(4-guanidinobenzoyloxy) phenyl] propionate methanesulfonate (TT-S24) on pancreatic secretion in rats

The effect of methylcarbonylmethyl 2(S)-[4-(4-guanidinobenzoyloxy) phenyl] propionate methanesulfonate (TT-S24), a newly synthesized trypsin inhibitor, on exocrine pancreatic secretion was examined and compared with that of camostat in rats. Intraduodenal (i.d.) administration of TT-S24 and camostat resulted in an increase in volume, amylase concentration and amylase output of pancreatic juice. Although i.v. injection of TT-S24 and camostat (3 mg/kg) had no effect on the pancreatic juice volume, TT-S24 (i.v.) dose-dependently increased pancreatic juice volume under acetylcholine (10 micrograms/kg/min) infusion. In addition, the weight of pancreases from WBN rats was significantly increased by 28 day oral administration of TT-S24 (100 mg/kg) with a potency similar to that observed with camostat.

[Continuous arterial infusion of protease inhibitor with supplementary therapy for the patients with severe acute pancreatitis--clinical effect of arterial injection of ulinastatin]

We treated five patients with severe acute pancreatitis by continuous arterial infusion (CAI) of protease inhibitor, nafamostat mesilate. Arterial injection (AI) of ulinastatin was performed in four cases and AI of antibiotics (IPM/CS) was done in one case, as supplemental therapies of CAI. Abdominal pain disappeared in 7.9 hours on the average, abdominal tenderness disappeared in 5.0 days and laboratory data lately recovered. All five cases treated by these therapies were cured without hemodialysis or surgical treatment in acute phase. AI of ulinastatin through arterial infusion catheter is pharmacokinetically more effective, because it yields a relatively high concentration of the drug at the acting site when compared with that of intravenous injection. Furthermore ulinastatin inhibits different types of protease from nafamostat mesilate. Therefore the clinical effect of CAI of nafamostat mesilate is enhanced by the combined therapy with AI of ulinastatin. It is also suggested that arterial injection of ulinastatin might be effective for the control of abdominal pain and that arterial injection of antibiotics might have an advantage on prevention of infectious pancreatic necrosis.

[Effects of constant-current electric field on tissue and plasma proteolysis in acute pancreatitis]

The tissue and plasma proteolysis changes were studied up on white laboratory rats while the pancreas zone galvanization using electrical field of 0.01-0.05-0.10 mA/cm2 density during 60 minutes. It was established that intratissue electrophoresis with contrykal lowers the low molecular mass peptides lysis by 6.6 times, the high molecular mass peptides-by 4.4, collagen-by 3.

[A clinical phase III trial of MR-20 in gynecologic nephrotoxicity of cisplatin--a comparative study in MR-20-treated and control patients on cyclical intermittent cisplatin treatment]

MR-20 was administered to 52 gynecological cancer patients who presented with nephrotoxicity from cisplatin (CDDP) treatment over 3 courses at 33 institutions throughout Japan during the period from July 1992 through March 1994, in order to study its suppressive effect on the nephrotoxicity as well as its safety; and the results are reported in this paper.

METHODS

The efficacy and usefulness of MR-20 were studied by a MR-20-untreated-controlled, non-double-blind manner. An efficacy rate of 72.0% was achieved in the MR-20 group, and 37.0% in the untreated group: MR-20 was significantly more effective for nephrotoxicity than the MR-20-untreated group. Ccr was prevented from significant variations in the MR-20 group, compared with the untreated group. It was considered that MR-20 is a safe drug, and that it is useful in suppressing the nephrotoxicity of CDDP treatment.

[Effects of ulinastatin on PMNL and vascular endothelial injury in patients undergoing open heart surgery with CPB]

Activated leukocytes are thought to contribute to respiratory dysfunction, alterations in microvascular permeability, disseminated intravascular coagulation, and thrombosis, all of which can complicate cardiopulmonary bypass (CPB). We have measured the levels of circulating proinflammatory cytokines (IL-6, 8), polymorphonuclear leukocytes elastase (PMNL-E), and vascular endthelial factors (ET-1, TM, sICAM-1) in patients undergoing open heart surgery with CPB. Patients were divided into a control group and a ulinastatin group. We have examined the effects of ulinastatin on these humoral mediators and postoperative pulmonary function. Every factor except IL-8 increased after CBP in control group. IL-6 and PMNL-E declined sharply to normal level in a few hours, but it took several days after surgery for ET-1, TM, and sICAM-1 to return to preoperative levels. Ulinastatin significantly suppressed the elevation of PMNL-E after CPB, indirectly suppressing the increase of other factors. There was no significant relationship between levels of humoral mediators and postoperative pulmonary function between the two groups. Our results suggest that ulinastatin alleviates the damage of vascular endothelium due to CPB (first attack), and this may be beneficial to reduce excessive inflammatory reaction against secondary insults.

[A clinical phase II trial of ulinastatin (MR-20) for nephrotoxicity of cisplatin]

MR-20 was administered to 37 lung cancer patients who presented with nephrotoxicity due to cisplatin (CDDP) treatment in an 11-institution cooperative trial during the period from September 1990 through March 1992 to study its suppressive effect on the nephrotoxicity as well as its safety. The results are reported in this paper.

METHODS

MR-20 was administered at 3 daily doses, ie. 150,000, 300,000 and 600,000 units, in a nonblind manner. An efficacy rate of 27.3% was achieved in the group at 150,000 units; 44.4% in the group at 300,000 units; and 45.5% in the group at 600,000 units. Serum Cr levels remained significantly lower in the group at 300,000 units during the treatment period than in the screening period. No adverse reactions to MR-20 were observed. According to the above results, it was anticipated that MR-20 would suppress the nephrotoxicity of CDDP treatment and be safe, and that the drug at a dose of 300,000 units daily would be useful in suppressing the nephrotoxicity.

[A clinical phase III trial of ulinastatin (MR-20) for nephrotoxicity of cisplatin]

MR-20 was administered to 140 lung cancer patients who presented with nephrotoxicity due to cisplatin (CDDP) treatment at 59 institutions throughout Japan during the period from September 1992 through March 1994 to study its suppressive effect on the nephrotoxicity as well as its safety. The results are reported in this paper.

METHODS

The efficacy and usefulness of MR-20 were studied in a placebo-controlled, double-blind manner. An efficacy rate of 58.7% was achieved in the MR-20 group, and 36.8% in the placebo group: MR-20 was significantly more effective for nephrotoxicity than placebo (U-test). Serum Cr, Ccr and FENa were prevented from significant variations in the MR-20 group, compared with the control group. It was considered that MR-20 is a safe drug, and that it is useful in suppressing the nephrotoxicity of CDDP treatment.

Preventive effect of ritodrine hydrochloride and/or urinary trypsin inhibitor against lipopolysaccharide-induced preterm delivery in mice

BACKGROUND

The purpose of this study was to confirm the preventive effect of ritodrine hydrochloride (ritodrine) alone or ritodrine plus urinary trypsin inhibitor (UTI) in a mouse model of preterm delivery.

METHODS

On day 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given two intraperitoneal injections of lipopolysaccharide (LPS) (50 micrograms/kg) at a 3-hour interval, which induced a 100% incidence of preterm delivery within 25 hours of the second dose. Ritodrine (1, 3, or 10 mg/kg, p.o.), UTI (25 X 10(4) units/kg, i.p.), ritodrine (3 mg/kg, p.o.) plus UTI (25 x 10(4) units/kg, i.p.), distilled water (10 ml/kg, p.o.), or distilled water (10 mg/kg, p.o.) plus saline solution (10 ml/kg, i.p.) were administered to the pregnant animals 10 times at 1-hour intervals from 8:00 AM to 5:00 PM on day 18 of pregnancy. In addition, the preventive effect of ritodrine, UTI, or ritodrine plus UTI was examined on LPS-induced contraction of uterine muscle strips isolated from pregnant mice on day 17 of gestation.

RESULTS

The incidence of preterm delivery decreased significantly in a dose-dependent fashion with ritodrine treatment, and there was a significant and synergistic decrease after combined treatment with ritodrine plus UTI. The in vitro uterine contraction induced by LPS was significantly suppressed by both ritodrine and UTI.

CONCLUSIONS

Combination therapy with ritodrine plus UTI may be helpful for preventing preterm delivery in humans without the cardiovascular side effects that often accompany treatment with ritodrine alone.

Stimulation of exocrine pancreatic secretion by soybean trypsin inhibitor does not depend on the masking of luminal trypsin activity in rats that have bile-pancreatic juice diverted into the ileum

We reported previously that dietary proteins stimulate pancreatic secretion by a mechanism not involved in masking trypsin activity in rats that have bile-pancreatic juice (BPJ) diverted from the proximal small intestine for 7 days. However, BPJ in the distal small intestine is possibly responsible for the stimulation of pancreatic secretion in chronic BPJ-diverted rats. To examine whether the BPJ-dependent mechanism operates in the distal small intestine of chronic BPJ-diverted rats, we investigated pancreatic responses after inhibition or removal of pancreatic trypsin activity in the distal small intestine of conscious rats. Duodenal instillation of soybean trypsin inhibitor (SBTI), which is a proteinaceous trypsin inhibitor, stimulated pancreatic secretion in the chronic BPJ-diverted rats, whereas a nonpeptidic trypsin inhibitor, FOY 305, did not. Ileal administration of both trypsin inhibitors did not enhance pancreatic secretion in the diverted rats. Exclusion of luminal BPJ from the distal small intestine was also ineffective in causing pancreatic exocrine secretion in the chronic BPJ-diverted rats. These observations reveal that ileal BPJ does not contribute to the stimulation of pancreatic secretion in rats that have BPJ chronically diverted into the ileum, as in intact rats, and that a duodenal instillation of SBTI stimulates pancreatic secretion as a protein, and not as a trypsin inhibitor.

[A case of chronic necrotizing pulmonary aspergillosis successfully treated with combination therapy of antifungal drugs and ulinastatin]

A 64-year-old woman with a history of old tuberculosis, had a fungus ball shadow with meniscus sign in the upper right lung field on a chest X-ray film in 1991. Based on the chest X-ray findings, pulmonary aspergilloma was suspected. Because the size of the intracavitary fungus ball increased, the patient was treated with itraconazole over one year in 1995, but there was no improvement. One month later, she was admitted because of fever, hemoptysis and productive cough, and chest X-ray showed an enlargement of intracavitary mass and infiltrative shadow in the right lung. Chronic necrotizing aspergillosis was diagnosed on the basis of her clinical and radiographic features, and positive serological test. Although itraconazol and amphotericin B were given, cavity and intracavitary fungus ball shadow kept growing. Combination therapy of antifungal drugs and ulinastatin markedly improved symptoms and resulted in complete disappearance of the fungus ball on chest CT scan.

Pharmacokinetic study of alpha1-antitrypsin infusion in alpha1-antitrypsin deficiency

OBJECTIVES

To ascertain how long 120 mg/kg alpha1-antitrypsin concentrate (alpha1-AT-C), administered I.V. every 2 weeks, can maintain alpha1-antitrypsin (alpha1-AT) serum levels above 70 to 80 mg/dL. Secondary objectives were to summarize the nature, severity, and relationship of a plasma-derived alpha1-AT-C infusion to any side effects.

METHODS

This was an open-label uncontrolled pharmacokinetic study. Alpha1-AT-C was administered I.V. every 2 weeks for 10 infusions in 23 patients with PIZ alpha1-AT deficiency. Serum alpha1-AT levels and neutralizing elastase activity were measured preinfusion, postinfusion, and at nadir. During two infusion periods, daily serum alpha1-AT and neutralizing elastase activities were measured on the seventh to 14th days. Five patients received BAL assays for alpha1-AT and neutralizing elastase activity. Adverse events were recorded in a patient diary and by a nurse at each infusion visit.

RESULTS

The 120-mg/kg dose of alpha1-AT-C could not maintain nadir serum protective levels above 70 or 80 mg/dL for the entire 14-day dosing interval in most patients. None of the patients had alpha1-AT levels above 80 mg/dL for all 14 days. The serum alpha1-AT and neutralizing elastase levels correlated suggesting functional activity. The BAL alpha1-AT and neutralizing elastase activities were low and did not correlate with serum levels.

CONCLUSION

Alpha1-AT-C at 120 mg/kg administered every 2 weeks did not maintain nadir serum alpha1-AT levels above 70 to 80 mg/dL for a 14-day dosing interval. Higher doses every 2 weeks or decreased interval between infusions may be required.

Long-term consumption of an amino acid diet reduces the pancreatic enzyme secretion response to a trypsin inhibitor in rats

We investigated pancreatic enzyme secretion in response to soybean trypsin inhibitor (SBTI) in rats fed amino acids as a nitrogen source, from the fetal stage to adulthood. Pregnant rats were divided into two groups 4 d before parturition. During gestation and nursing, one group was fed a 15% protein diet (protein-fed rats) and the other (amino acid-fed rats) a 15% amino acid mixture diet that simulated the composition of the protein diet. Each male offspring was weaned at 4 wk after parturition and fed the same diet as fed to its dam for an additional 6 wk. Pancreatic amylase secretion in response to an intraduodenal infusion of SBTI (10 mg/rat) was observed in the protein-fed rats but not in the amino acid-fed rats. Amylase secretion in response to an intravenous injection of cholecystokinin (CCK) (10 ng/kg rat) was observed in both groups, and the magnitude of the response was significantly higher in the amino acid-fed rats than in the protein-fed rats. An increase in the level of plasma CCK in response to SBTI was observed in the protein-fed rats but not in the amino acid-fed rats. These results suggest that the long-term amino acid diet, because of its ability to inhibit the SBTI-stimulated CCK-releasing process in the small intestine of rats, reduced the pancreatic enzyme secretion response to a trypsin inhibitor. Six rats fed the amino acid mixture until 1 wk after weaning were fed the protein diet for the next 5 wk. These rats showed no pancreatic amylase secretion in response to SBTI, suggesting that dietary components around the weaning stage may affect the development of the ability of small intestinal cells to recognize a trypsin inhibitor.

Metabolic fate of ulinastatin (2); Pharmacokinetics in rabbits following intra-articular administration

The absorption and distribution of ulinastatin following intra-articular administration of [125I]ulinastatin to rabbits were determined and kinetic analysis using a multi-compartment model was performed. At 4 h after administration, the content of radioactivity in the synovial fluid, which was comparable to that of the immunoreactive ulinastatin, was 14.51% of the dose and decreased in a biphasic manner. The highest level of radioactivity was observed in the synovial membrane, followed by the meniscus, ligament, cartilage and patella, the radioactivities of which also declined biphasically. After intra-articular administration, the plasma concentration of total radioactivity increased slowly and reached maximum at 4.3 h, and then declined slowly in a monophasic manner with a half-life of 10.8 h. The radioactivity of the high molecular weight fraction in plasma, which reached maximum at 1.7 h after administration and then declined with a half-life of 11.8 h, was consistent with the time curve for immunoreactive ulinastatin in the plasma through 24 h after the administration. Within 8 and 24 h after administration, respectively, 1.48 and 4.66% of the administered radioactivity were transferred to the lymphatic fluid. The pharmacokinetics of [125I]ulinastatin after an intra-articular administration could be explained using a multi-compartment model in which a portion of the administered ulinastatin was absorbed via the lymphatic system. This finding suggested that ulinastatin was rapidly distributed and retained for a long period of time in the joint tissues. In addition, the pharmacokinetics of ulinastatin following intra-articular administration indicated typical flip-flop kinetics.