Effects of anthocyanidin derivative (HK-008) on relaxation in rat perfused mesenterial bed.

Anthocyanins, which are responsible for a variety of bright colors (including red, blue, and purple) in fruits, vegetables, and flowers, are consumed as dietary polyphenols. Anthocyanin-containing fruits are thought to decrease coronary heart disease and are used in anti-diabetic preparations. Diabetes is associated with a variety of cardiovascular complications that may be mediated by endothelial dysfunction, and so this study was designed mainly to characterize the influence of a synthesized anthocyanidin derivative (HK-008) over acetylcholine (ACh)-induced relaxation in mesenteric arterial beds isolated from rats. In a glucose-tolerance test in intact rats, HK-008 (30 mg/kg) reduced the glucose level as effectively as the same dose of glibenclamide. The aortic relaxation induced by pinacidil (an ATP-sensitive potassium channel opener) was greatly inhibited by glibenclamide (10 microM), and also significantly inhibited by HK-008 (10 microM). Interestingly, the ACh-induced relaxation in the perfused, preconstricted mesenteric arterial bed was significantly enhanced by HK-008 (10 microM), and this enhancement was significantly attenuated by indomethacin (10 microM). The ACh-induced mesenteric relaxation was impaired by an increase in oxidative stress, viz. superoxide-generating treatment [xanthine oxidase (XO; 0.1 U/ml) plus hypoxanthine (HX; 10 microM)]. However, this impairment was strongly suppressed by HK-008 (10 microM). These results suggest that HK-008 increases endothelium-induced relaxation by suppressing oxidative stress or modulating prostanoids signaling. This compound may therefore be useful against certain cardiovascular disorders.     

Effects of anti-asthmatic drugs on human eosinophil chemotaxis]

To evaluate the acute effects of anti-asthmatic drugs in vitro, we examined the modulation of various anti-asthmatic drugs in therapeutic concentrations on PAF-induced human eosinophil chemotaxis. Aminophylline (20 micrograms/ml) and Isoproterenol (10 nM) inhibited PAF (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas no inhibitory effects were observed by Dexamethasone (0.1 microM), Tranilast, Ketotifen or Azelastine. Aminophylline (20 micrograms/ml) also inhibited LTB4 (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas it did not inhibit chemotaxis induced by zymosan (5 mg/ml)-activated serum. These results indicate that anti-asthmatic drugs except for aminophylline and isoproterenol, when used acutely in therapeutic concentrations, have no striking inhibitory effects on PAF-induced eosinophil chemotaxis. These results further suggest the possibility that there are different mechanisms in eosinophil chemotaxis induced by PAF, LTB4 or by C5a.     

Isolation, purification, and characterization of an acidic protein in the cerebrospinal fluid of central nervous system disease.

Proteins from 21 cerebrospinal fluid (CSF) samples (14 derived from neurological cases and 7 from normal individuals) and 15 serum samples (11 from neurological cases and 4 from normal individuals) were analyzed by two-dimensional electrophoresis. Protein mapping revealed a very acidic protein (Ac-P) at about pH 3.5 in the 71% of CSF samples from neurological cases. However, no serum sample contained Ac-P. Ac-P was isolated and purified, and determined to be a glycoprotein containing a large amount of carbohydrate, with molecular weight 42,000 and isoelectric point 2.7-3.3. The amino acid composition of Ac-P was consistent with alpha 1-acid glycoprotein (AGP), and Ac-P was responsive to a commercial anti-AGP antiserum in the radial immunodiffusion test. The known polymorphism of AGP suggests some differences in physicochemical properties such as molecular weight and isoelectric point between AGP in serum and in CSF. Quantitative analysis of Ac-P (AGP) and total protein levels in CSF showed a partial interdependence. Ac-P may be a useful marker for detecting a pathological conditions of the central nervous system.     

Effects of chronic administration of L-arginine on vasoactive responses induced by endothelin-1 and its plasma level in streptozotocin-induced diabetic rats.

To investigate the mechanism underlying increased endothelin-1 (ET-1) release in diabetic rats, we administered L-arginine chronically to streptozotocin (STZ)-induced diabetic rats. The plasma concentrations of glucose, ET-1 and NOx (NO2- + NO3-) were all significantly raised at 10 weeks after the STZ injection. Chronic administration of L-arginine resulted in a significantly higher plasma NOx concentration and a significantly lower plasma ET-1 level at 10 weeks compared with the untreated diabetic group. ET-1 induced a biphasic vasodilator/vasoconstrictor response in the perfused isolated mesenteric arterial beds from all groups. The vasodilatation was significantly greater in diabetic rats than in age-matched controls. Chronic oral L-arginine administration had no significant effect on the enhanced ET-1-induced vasodilatation seen in the untreated diabetic rats. The vasoconstrictions induced by ET-1 and methoxamine were significantly attenuated in STZ-diabetic rats. The attenuated vasoconstrictor response to ET-1, but not that to methoxamine, was further attenuated by chronic treatment with L-arginine. We conclude that since chronic L-arginine administration not only reduced the increase in plasma ET-1 levels but also further attenuated the ET-1-induced vasoconstriction without affecting the change in vasodilatation, chronic L-arginine administration could be valuable for the treatment of the symptoms of diabetic mellitus related to ET-1.     

A case of Sweet's syndrome (acute febrile neutrophilic dermatosis) associated with mixed connective tissue disease]

Sweet's syndrome (acute febrile neutrophilic dermatosis) is an unusual condition characterized by fever, polymorphonuclear neutrophil leukocytosis of the blood, thick painful plaques on the face, neck and limbs, and a dense dermal infiltrate of mature neutrophils seen histologically. Recently, this disease has also been reported in association with various malignant neoplasms and chronic inflammatory disorders. In the literature, seven cases of Sweet's syndrome associated with collagen diseases have been reported, but no cases with mixed connective tissue disease (MCTD). The first case of Sweet's syndrome associated with MCTD was herein described and discussed. A 49-year-old man was admitted to our hospital with the complaints of high fever and painful erythema on his face, neck and limbs. Six months ago, MCTD was suspected, with the presence of limited cutaneous sclerosis of the hands, Raynaud's phenomenon, polyarthralgia, an elevation of CPK value and a positive anti-RNP antibody. Just before hospitalization, he suffered a prodromal infection of the upper respiratory tract for two weeks. He was diagnosed as Sweet's syndrome by the clinical and histological features. He began receiving corticosteroid therapy (prednisolone 60 mg/day), and within a week he showed dramatic improvement in the above symptoms.     

Pharmacological studies of the new antiinflammatory agent 3-formylamino-7-methylsulfonylamino-6-phenoxy-4'-1-benzopyran-4-o ne. 2nd communication: effect on the arachidonic acid cascades.

The in vitro and in vivo effects of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0), a new antiinflammatory agent, on arachidonic acid metabolism were investigated in comparison with those of reference drugs. Although the inhibitory effect of T-614 on the synthesis of prostaglandins by rabbit renal microsomes was very weak (IC50 of 58 micrograms/ml), T-614 effectively inhibited the prostaglandin E2 (PGE2) generation by mouse fibroblasts stimulated with bradykinin with an IC50 value of 0.47 micrograms/ml. The suppressive effect of T-614 on the PGE2 generation in fibroblasts was also found when cells were stimulated with Ca ionophore A23187, but not when induced with arachidonic acid. T-614 suppressed the A23187-induced PGE2 generation by rat macrophages, but not the leukotriene B4 production. In addition, 5-lipoxygenase activities in guinea-pig peritoneal exudated cells were not inhibited. In in vivo experiments, at doses of more than 1 mg/kg, T-614 reduced the PGE2 contents in inflammatory exudate of rat carrageenin-sponge type inflammation, but it was almost inactive in inhibiting gastric prostaglandins production up to 100 mg/kg. T-614 also did not affect the urinary PGE2 excretion in rats, and slightly inhibited the thromboxane synthesis in rat blood. Furthermore, the convulsion-induced increase of PGE2 in mouse brain was inhibited by T-614. These data suggest that T-614 inhibits the production of cyclooxgenase-mediated products with apparently different mode from classical non-steroidal antiinflammatory drugs, and may partly explain the discrepancy in pharmacological properties between this compound and other drugs.