Histopathological study of kidney abnormalities in an experimental SIADH rat model and its application to the evaluation of the pharmacologic profile of VP-343, a selective vasopressin V2 receptor antagonist.

The aim of this work was to investigate histopathologically the relationship between the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and kidney abnormalities and the therapeutic efficacy of VP-343 ((N-[4-[[(2S,3aR)-2-hydroxy-2,3,3a,4-tetrahydropyrrolo[1,2-alqunoxalin-5(1H)-yl]phenyl]-4'-methyl[1,1'-biphenyl]-2-carboxamide], a selective vasopressin V2 receptor antagonist, in an experimental SIADH rat model. In the model, which was prepared by continuously administering 1-desamino-8-D-arginine vasopressin (DDAVP), histopathologic abnormalities, such as dilatation of tubules, basophilic changes in tubules, inflammatory cell infiltration, and mineralization were found in the kidney, accompanied by significant increases in the relative weight of the kidney, lung, liver, adrenal gland, and heart. VP-343 was shown to be effective in protecting the kidney from the histopathologic abnormalities and to normalize the relative weight of the kidney and several common pathophysiologic features, such as hyponatremia, hyposmolarity of plasma, hyperosmolarity of urea, and oligurea, as described previously. These results demonstrate the occurrence of histopathologic abnormalities in the kidney and the efficacy of VP-343 in improving abnormalities in the DDAVP-induced SIADH rat model.

The therapeutic efficacy of VP-343, a selective vasopressin V2 receptor antagonist, in the experimental SIADH rat model.

The aim of this work is to investigate the therapeutic efficacy of VP-343 ((N-[4-[[(2S,3aR)-2-hydroxy-2,3,3a,4-tetrahydropyrrolo[1,2-a]qunoxalin-5(1H)-yl]phenyl]-4'-methyl[1,1'-biphenyl]-2-carboxamide), a selective vasopressin V2 receptor antagonist, using the experimental SIADH (syndrome of inappropriate secretion of antidiuretic hormone) rat model. In the model, which was accomplished by administering continuously 1-desamino-8-D-arginine vasopressin (DDAVP), serum sodium levels (S(Na)) and serum osmolarity levels (S(Osm)) significantly and remarkably decreased, which was accompanied with hyper-osmolarity of urine and oliguria. VP-343 increased rapidly and dose-dependently S(Na) and S(Osm). VP-343 exhibited marked diuretic action and decreased urine osmolarity dose-dependently. In the SIADH rat model, all serum levels of chloride, calcium, creatinine, total cholesterol, and uric acid decreased when compared with normal levels. VP-343 increased all serum levels of chloride, calcium, and total cholesterol. These results indicate that VP-343 has efficacy to normalize the abnormalities in DDAVP-induced SIADH.

Affinity chromatography for purification of two urokinases from human urine.

A new affinity chromatography (hydrophobic-mediated affinity chromatography), which was characterized by the matrix having both affinity site to urokinase and hydrophobic site, was established for the purification of urokinase from human urine. The hydrophobic affinity matrix (tentatively named PAS in the text) was prepared by immobilizing 6-aminocaproic acid on Sepharose CL-6B, followed by a coupling p-aminobenzamidine to a part of the hydrophobic site on the matrix. The PAS matrix was applied to the purification of urokinase from human urine, and high- and low-molecular weight pure urokinases were efficiently obtained in high yield by the present method.

Pharmacological profile of VP-343, a novel selective vasopressin V2 receptor antagonist, in rats.

The pharmacological profile of a novel selective vasopressin V2 receptor antagonist, VP-343(N-[4-[[(2S,3aR)-2-hydroxy-2,3,3a,4-tetrahydropyrrolo[ 1,2-a]quinoxalin-5(1H)-yl]carbonyl]phenyl]-4'-methyl[1,1'-biphenyl ]-2-carboxamide) was characterized in several in vitro and in vivo rat models. The IC50 values of VP-343 for vasopressin V1A and V2 receptors were 110 and 0.77 nM, respectively. VP-343 inhibited dose-dependently the pressor response to exogenous arginine vasopressin (AVP; 30 mU/kg, i.v.) in pithed rats, with an ID50 value of 0.57 mg/kg (i.v.). VP-343 induced strong aquaresis in normal saline-loaded conscious rats. Antidiuretic activities of VP-343 have not been detected in AVP deficient Brattleboro rats, showing its lack AVP V2 agonistic activity. During repeated administration for 21 d (3 mg/kg, p.o.) and after recovery, the aquaretic action of VP-343 still remained. In the aged (17 month) saline-loaded conscious rats study, VP-343 (3 mg/kg, p.o.) exhibited remarkable diuretic action. In a single dose oral toxicity study in mice, VP-343 did not produce any clinical signs and mortality at any of the tested doses. The results indicate that VP-343 is a potent, orally active, selective V2 receptor antagonist, suggesting that it can be expected to be useful as an aquaretic drug.

Matrix metalloproteinase activity is enhanced during corneal wound repair in high glucose condition.

PURPOSE: (1) To investigate the effect of elevated extracellular glucose on migration, proliferation, and the activity of matrix metalloproteinases (MMPs) of SV40-transformed human corneal epithelial cells (HCEC). (2) To examine MMP activity in wounded corneal epithelium in diabetic rats. METHODS: HCEC were cultured in media containing 5.5 mM or 31.2 mM D-glucose, or in a combination of 5.5 mM D-glucose and 25.7 mM D-mannitol on fibronectin/collagen I-coated 48-well plates. After reaching confluence (day 0), cells in the central part of the plate were wounded and the residual cells were cultured for 3 days. Migration and proliferation were evaluated by assessing the increasing amount of area covered by cells, and the day-3 to day-0 ratio of DNA levels, respectively. To determine MMP activity, cells were reacted with synthetic fluorogenic substrates specific to MMPs 1, 2, 3, 7, 9, and MMP activity was determined by a fluorometric kinetic assay. Diabetic rats were induced by streptozotocin injection. Corneal epithelium was scraped from limbus-to-limbus and allowed to heal. Normal rats were treated similarly to serve as controls. Healing epithelium was collected 24 hours later, and gelatin zymography was performed. RESULTS: In the cell culture study, migration in 31.2 mM glucose was significantly slower than that in 5.5 mM, but proliferation in each concentration was similar. The osmotic effect of D-mannitol did not alter migration or proliferation. MMP activity in 31.2 mM was significantly higher than that in 5.5 mM. Zymography revealed enhanced activity of pro and active MMP-9 in healing corneal epithelium in diabetic rats. CONCLUSIONS: MMP activity was enhanced in healing corneal epithelium, both in in vitro and in vivo diabetic models, suggesting its involvement in diabetic keratopathy.

Novel vasopressin V2 receptor-selective antagonists, pyrrolo[2,1-a]quinoxaline and pyrrolo[2,1-c][1,4]benzodiazepine derivatives.

The intent of the work was to study the structure-activity relationships of AVP receptor antagonists bearing a chiral ring as a partial structure since such studies had been reported for only achiral compounds. In the present paper, we deal with compounds consisting of the chiral tricyclic hetero ring (1,2,3,3a,4,5-hexahydropyrrolo[1,2-a]quinoxaline and 1,2,3,10,11,11a-hexahydro-1H-pyrrolo[2,1-c][1,4]benzodiazepine) and 2-phenylbenzanilide analogues. These compounds exhibited a highly selective affinity for V2 receptor, and their stereochemical configuration had a great influence on V2 receptor binding. VP-343 (N-[4-[[(2S,3aR)-2-hydroxy-2,3,3a,4-tetrahydropyrrolo[1,2-a] quinoxalin-5(1H)-yl]carbonyl]phenyl]-4'-methyl[1,1'-biphenyl]-2-ca rboxamide), VP-365 (N-[4-[[(11aS)-2,3,11,11a-tetrahydro-1H-pyrrolo[2,1-c][1,4]benz odiazepin-10(5H)-yl]carbonyl]phenyl][1,1'-biphenyl-2-carboxamide) and VP-339 (N-[4-[[(11aS)-5-oxo-2,3,11,11a-tetrahydro-1H-pyrrolo[2,1-c][1,4]+ ++benzodiazepin-10(5H)-yl]carbonyl]phenyl][1,1'-biphenyl]-2-carboxami de) were the most potent compounds in vitro and in vivo. The IC50 values of VP-343, VP-365 and VP-339 against V2 receptor were 0.772, 1.18 and 0.216 nM, respectively. The ED300 values (dose required to increase three times the urine volume of the control rats; oral administration) of VP-343, VP-365 and VP-339 were 0.22, 0.31 and 0.78 mg/kg, respectively.

Manufacturing High Purity Maltose and Maltotetraose from Starch by a Novel and Efficient Procedure Named "Reducing End Modification Method".

A novel and efficient procedure named "reducing end modification method" was developed for manufacturing high purity maltooligosaccharides. By the method, high purity maltose and maltotetraose were prepared from starch. Starch was liquefied, debranched, and oxidized with sodium hypochlorite at the reducing end. The reaction mixture was treated with ß-amylase or maltotetraose-forming amylase from Pseudomonas stutzeri IFO-3773, resulting in the production of high purity maltose or maltotetraose, oxidized maltooligosaccharides, and oxidized undigested dextrin. High purity maltose (maltose content, 99.9%) or maltotetraose (maltotetraose content, 95%) was obtained very effectively from the reaction mixture by chromatography on a strong acid cation exchange resin (Na (+)).

Enzymatic synthesis of 4-O-beta-D-galactopyranosyl-moranoline and 3-O-beta-D-galactopyranosyl-moranoline by using beta-galactosidase from Bacillus circulans.

A transgalactosylation reaction from lactose to moranoline (1-deoxynojirimycin) was accomplished by using beta-galactosidase [EC 3.2.1.23] from Bacillus circulans. The enzyme formed 3-O-beta-D-galactopyranosyl-moranoline and 4-O-beta-D-galactopyranosyl-moranoline as major products, together with 2-O-beta-D-galactopyranosyl-moranoline and 6-O-beta-D-galactopyranosyl-moranoline as minor ones.

Effects of moranoline, 4-O-alpha-D-glucopyranosylmoranoline and their N-substituted derivatives on thermostability of cyclodextrin glycosyltransferase, glucoamylase, and beta-amylase.

In repeated glycosylmoranolines synthetic reaction at 55 degrees C, cyclodextrin glycosyltransferase (CGT-ase, EC 2.4.1.19) from Bacillus stearothermophilus retained its activity for more than 600 days. A main stabilizing compound was found to be 4-O-alpha-D-glucopyranosylmoranoline. The thermostabilizing activities of moranoline, 4-O-alpha-D-glucopyranosylmoranoline, and their N-substituted derivatives were studied. Moranoline and its N-substituted derivatives stabilized glucoamylase. 4-O-alpha-D-Glucopyranosylmoranoline and its N-substituted derivatives stabilized CGT-ase and beta-amylase.

A novel and efficient method for enzymatic synthesis of high purity maltose using moranoline (1-deoxynojirimycin).

A transglycosylation reaction with moranoline (1-deoxynojirimycin) was done with soluble starch as the glucosyl donor and Bacillus macerans amylase as a cyclodextrin glycosyltransferase [EC 2.4.1.19]. The resultant transglycosylation products with moranoline, obtained by treating the reaction mixture with a strong cation exchange resin, were hydrolyzed by beta-amylase [EC 3.2.1.2] from sweet potatoes. The hydrolysate was treated with a strong cation exchange resin, and high purity maltose was obtained.

Synthesis and alpha-glucosidase-inhibiting activity of a new alpha-glucosidase inhibitor, 4-O-alpha-D-glucopyranosylmoranoline and its N-substituted derivatives.

Various N-substituted derivatives of 4-O-alpha-D-glucopyranosylmoranoline have been synthesized, and their inhibitory activities against rabbit sucrase and maltase have been measured, as well as their effects on postprandial hyperglycemia in the sucrose-loaded rat, 4-O-alpha-D-Glucopyranosylmoranoline was also shown to have potent hypoglycemic activity in starch-loaded dogs.

Inhibition of intestinal alpha-glucosidase and postprandial hyperglycemia by N-substituted moranoline derivatives.

The inhibitory activity of N-substituted derivatives of moranoline (1-deoxynojirimycin) against intestinal alpha-glucosidase and postprandial hyperglycemia was evaluated. None of the N-substituted derivatives studied displayed more potent inhibition of sucrase or maltase from rabbit intestines than the parent compound moranoline. However, unlike the in vitro results, many compounds exhibited more potent hypoglycemic activities than moranoline in sucrose-, or starch-loaded rat models. Alkenyl or aralkenyl derivatives displayed more potent hypoglycemic activities than alkyl or aralkyl derivatives. There was a weak correlation between in vitro and in vivo assay systems found by statistical analysis. It is necessary to evaluate compounds in vivo in order to select the most potent hypoglycemic compound.

OF4949, new inhibitors of aminopeptidase B. I. Taxonomy, fermentation, isolation and characterization.

New aminopeptidase B inhibitors that we named OF4949-I, II, III and IV were isolated from the culture broth of a fungus, Penicillium rugulosum OF4949. The molecular formula of I was C23H26N4O8 and that of II, C22H24O8, judging from elemental analysis and secondary ion mass spectrometry. The concentrations of I, II, III and IV required for 50% inhibition of aminopeptidase, using Ehrlich ascites carcinoma cells as the source of the enzyme, were 0.0054, 0.0048, 3.4 and 1.7 micrograms/ml, respectively. Components I and II augmented delayed-type hypersensitivity in mice to sheep red blood cells.

OF4949, new inhibitors of aminopeptidase B. II. Elucidation of structure.

The structures of OF4949-I, II, III and IV were identified by analysis of the products of their chemical degradation and by 1H NMR, 13C NMR, and mass spectrometry. These compounds were new cyclic peptides containing diphenyl ether as a chromophore. OF4949-I had two amino acids, beta-hydroxy-L-asparagine and 4-methylisodityrosine. The structural differences between I and II and between III and IV lay solely in the diphenyl ether moiety; the phenolic hydroxyl group in II and IV was methylated in I and III. OF4949-III and IV contained L-asparagine instead of the beta-hydroxy-L-asparagine moiety of I and II.