Search PubMed⌕ Search

Biomedical subjects

H Kitagawa

Publications and source records attributed to H Kitagawa.

At least 595 records · Page 33Linked to original sources
PubMed1981

Possible mechanism of inhibition by polyamines of lipid peroxidation in rat liver microsomes.

The rate of malondialdehyde formation in rat liver microsomes decreased as concentration of spermine added to the reaction mixture was increased. Inhibitory effect on lipid peroxidation was observed even when spermine was added at 15 min after the onset of reaction. Microsomal lipid peroxidation was markedly increased when extracted lipids were added to the reaction mixture. It was, moreover, found that in the presence of exogeneous microsomal lipids, spermine inhibition was weakened. The character of spermine inhibition with respect to the amounts of exogeneous and endogeneous lipids was shown to be competitive. From these results, it was suggested that spermine interaction with microsomal lipids may be responsible for the inhibition of lipid peroxidation.

Animals↗
PubMed1980

Changes in the serotonin and 5-hydroxyindoleacetic acid contents in rat brain after ethanol and disulfiram treatments.

Disulfiram (700 mg/kg, p.o.) significantly increased the brain levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in rats. Ethanol (1 g/kg and 2 x 1.5 g/kg, i.p.) did not affect the 5-HT level, but at the higher dose it significantly increased the 5-HIAA level. When disulfiram was given in combination with ethanol, the brain level of 5-HT was significantly higher and, conversely, the 5-HIAA level was significantly lower, as compared to the results with disulfiram alone. These results suggest that the biogenic aldehyde derived from 5-HT may influence 5-HT metabolism and the elimination of 5-HIAA from the brain.

Aldehyde Oxidoreductases↗
PubMed1980

Tryptophol-induced change in Brain 5-hydroxytryptamine Metabolism.

The effects of tryptoiphol (TOL) on brain 5-hydroxytryptamine (5-HT) metabolism were studied. After TOL injection (200 mg/kg IP), brain 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) levels were increased, 5-HT synthesis rate was decreased, and monoamine oxidase (MAO) activity remained unchanged. Pretreatment of mice with p-chlorophenylalanine (PCPA), a potent inhibitor of 5-HT synthesis, did not affect the anticonvulsant action of TOL.. These results suggest that alteration of 5-HT metabolism after TOL injection is not directly related to the anticonvulsant action of TOL

Animals↗
PubMed1980

Effect of p-chlorophenylalanine on diazepam withdrawal signs in rats.

The effect of p-chlorophenylalanine (PCPA), a specific serotonin (5-HT) depleter, on diazepam withdrawal signs was studied. Rats were made dependent on diazepam by the chronic administration of this drug in the diet. At the time of diazepam withdrawal, the animals were treated with PCPA (200 mg/kg, IP) or the corresponding vehicle (control). After diazepam withdrawal, the maximal body weight losses of control and PCPA-treated animals were 4.1% and 9.0%, respectively. In naive animals, PCPA did not cause any change in body weight. These results suggest that depletion of central 5-HT by PCPA may potentiate the severity of diazepam withdrawal signs.

Animals↗
PubMed1980

Experimental chronic non-suppurative destructive cholangitis in rabbits following immunization with bile duct antigen.

Experimental chronic non-suppurative destructive cholangitis induced in rabbits following immunization with bile duct antigen. Histological changes similar to chronic non-suppurative destructive cholangitis were induced in rabbits by sensitization with antigen prepared from bovine gallbladder mucous membrane. The occurrence of these pathological changes was significantly higher in female animals than in males: 11 out of 14 female rabbits and 4 among 11 male rabbits exhibited histological changes. Immunoprecipitation using gel-diffusion and histological analysis by an immunofluorescence technique showed that this antigen was localized exclusively in the bile duct but not in either hepatocytes or other tissues. It is suggested that histological changes induced following immunization with bile duct antigen are specific immunological phenomena. This interesting experimental model may be helpful in explaining the pathogenesis of primary biliary cirrhosis.

Animals↗
PubMed1980

Effect of diisopropyl 1,3-dithiol-2-ylidenemalonate on microsomal electron transport system in rat liver.

Effect of diisopropyl 1,3-dithiol-2-ylidenemalonate (NKK-105) on the components of rat liver microsomal electron transport system was investigated by comparison with those of phenobarbital, 3-methylcholanthrene and polychlorinated biphenyl. When NKK-105 was administered to rats at a dose of 250 mg/kg/day for 7 days, cytochrome b5 content and NADPH-cytochrome c reductase activity were significantly increased but cytochrome P-450 content to the lesser extent. Three inducers of the drug metabolizing enzymes remarkably increased cytochrome P-450 content but increased cytochrome b5 content to a lesser extent.

Animals↗
PubMed1980

Hyperglycemic effect of hydralazine in rats.

The effect of hydralazine in the alteration of blood sugar, tissue glycogen and blood cAMP levels in rats were investigated. Hydralazine was found to increase blood sugar level in intact rats when administered i.p. On the other hand, this hyperglycemia was partially blocked either by the treatment of intact rats with propranolol, beta-adrenergic blocker, or by adrenalectomy. Hydralazine treatment increased blood cAMP level, leading to the hyperglycemia, because pretreatment with phentolamine partially blocked the hydralazine-induced hyperglycemia.

Adrenal Glands↗
PubMed1980

Effects of polyamines on ethylmorphine N-demethylation in rat liver microsomes.

The time course linearity of ethylmorphine N-demethylation was improved by the addition of polyamines to the reaction mixture. The most remarkable effect on the time course linearity of ethylmorphine N-demethylation was observed when spermine was used. The apparent stimulatory effect of spermine was decreased remarkably by the simultaneous addition of EDTA to inhibit lipid peroxidation. Similar results were observed when an additional lipid peroxidation inhibitor such as Co2+, Mn2+ or 2,2'-bipyridine was used in place of EDTA. Hydrogen peroxide-dependent ethylmorphine N-demethylation activity in rat liver microsomes was not influenced by the addition of spermine. In addition, neither lipid peroxides formation nor the stimulatory effects of polyamines on ethylmorphine N-demethylation was observed in the reconstituted monooxygenase system. These results suggest that the inhibitory effects of polyamines on lipid peroxidation might be responsible for the stimulatory effects on drug oxidations.

Animals↗
PubMed1980

Microassay of gamma-glutamyl transpeptidase in needle biopsies of human liver.

A method is described for determination of liver gamma-GTP activity in homogenates of the small amount of human liver tissues (approx. 5--7 mg wet wt.) obtained by needle biopsy. The gamma-GTP activity in the liver of healthy subject was < 20 mU/mg protein. The microdetermination of gamma-GTP described here is worth in the diagnosis of hepatic injury, especially alcoholic hepatitis and drug-induced liver diseases.

Aniline Compounds↗
PubMed1980

5-Di-(2'-tetrahydropyranyl)secalonic acid D as a new antibiotic derivative with anticancer activity.

A pyranyl derivative was chemically synthesized from secalonic acid D, an antibiotic obtained from culture filtrates of Penicillium oxalium, and its anticancer activity towards a highly antigenic rat bladder cancer, BC-47, implanted into inbred ACI/N rat was studied. The anticancer effect of the drug was similar to that of adriamycin. Delayed initiation of treatment, starting 5 days after the cancer implantation, was more effective than treatment starting from day 1. In addition, it was less effective in an immunodeficient host subsequently implanted with BC-47. This compound is thought to retard the cancer cell growth until the appearance of tumor immunity in the host.

Animals↗