Kazuo Kasama

Metabolic fate of nitric oxide

SummaryThe metabolic pathway of inhaled NO in rats was investigated with 15NO. After 15NO exposure, the content of the 15N (atom % excess) in blood, red cells, serum, each organ tissue (perfused with saline solution) and urine were estimated. The contents of 15N in the samples of blood, serum, red cells, and urine were relatively high and those of lung, trachea, liver, kidney, and muscle were low.The rat blood samples 1 h after 15NO combined blood injection were analyzed. Greater parts of the 15N in the serum were in a fraction of the ultrafiltrate and the amounts of NO3−in the serum were remarkably elevated compared with those of the control rats.At 24 h and 48 h after 15NO combined blood injection, the urine samples were collected. Most of the 15N in the urine was found within 24 h.Red cells from the 15NO exposed rats were washed (mixed and incubated) with the saline solution or the serum from untreated rats. The 15N in the cells was easily extracted into the solution or serum, but the 15N in the serum from the exposed animals was scarcely transferred to the red cells.Throughout the experiments, it was supposed that inhaled NO primarily reacted with hemoglobin and was changed to NO2−and NO3−. Then the metabolites were transferred to serum, part of these reacted with tissues and the others were excreted in urine in the form of NO3−.

Biotransfornation of nitric oxide, nitrite and nitrate

SummaryBiotransformation of NO, nitrite and nitrate was investigated in rats and mice in a 15NO inhalation experiment and intraperitoneal injection experiments of 15N-nitrite and 15N-nitrate, and the following results were obtained:(1)Rats were forced to inhale 15NO (145 ppm,123 minutes) or were given an intraperitoneal injection of 15N-nitrite (2 mg animal−1 as 15N) or 15N-nitrate (2mg animal−1 as 15N), and determination of 15N recovery in urine was made up to 48 h later. The results were 55, 53 and 78% of the inhaled or injected 15N, respectively.(2)15N-nitrate in the urine was converted into a 6-nitro derivative of 3,4-xylenol and its identification and quantitative determination were made by the GGMS method. As to 15N-urea in the urine, identification and quantitative determination were made by the urease method. 15N was present in the urine of rats after 15NO inhalation in the form of N03− and urea. 75 and 24% respectively. In the urine of rats injected with 15N-nitrite, about 20% of unidentified 15N-compounds not discovered in the inhalation experiment was found. The content of 15N-urea in the urine after injection with 15N-nitrate was lower than that after injection with 15N-nitrite.(3)When 15N-nitrite (0.617 mg animal−1 as 15N) was injected intraperitoneally in mice, 60.7, 7.8 and 0.3% of the injected 15N were found in the urine, feces and exhaled gas (NO, N02 and NH3 in the gas were caught) up to 48 h after injection respectively, and 1.6% was found in the body 48 h after injection, but the remaining 30% of 15N could not be recovered.

Bis-(monoacylglyceryl) phosphate and acyl phosphatidylglycerol isolated from human livers of lipidosis induced by 4,4′-diethylaminoethoxyhexesterol

Bis-(monoacylglyceryl) phosphate and acyl phosphatidylglycerol were isolated from the liver of two patients with lipidosis induced by 4,4′-diethylaminoethoxyhexesterol. Identification was based upon the results of alkaline hydrolysis, acetolysis, IR spectrometry, and upon the determination of molar ratio of phosphorus-glycerol-ester. The contents of the bis-(monoacylglyceryl) phosphate were 10 and 16% total phospholipid phosphorus in them. The bis-(monoacylglyceryl) phosphate contained mainly docosahexaenoic (42%), oleic (29%), and linoleic acid (14%) and had the hemolytic activity of ca. one-eighth lysolecithin from egg yolk. Acidic lipids from the liver also were found to contain a lipid which is less polar than bis-(monoacylglyceryl) phosphate. The results of lipid analysis showed that the lipid possessed the structure of an acyl phosphatidylglycerol, and its content was ca. 2% total phospholipid phosphorus. Accumulation of 4,4′-diethylaminoethoxyhexesterol and its derivatives was found in clinical cases by thin layer chromatography and IR spectrometry. This fact suggested that human liver has an ability to metabolize the drug.

Antitumor effect of palmitoleic acid on Ehrlich ascites tumor.

Palmitoleic acid (PLOA) markedly prolonged the survival time of mice bearing Ehrlich ascites tumor at doses of 37.5-150 mg/kg/day X 10, but the antitumor activity of oleic acid (OA) was weaker than that of PLOA. The total lipid and phospholipid contents in the tumor cells treated with PLOA were significantly decreased. In addition, the fatty acid pattern of phosphatidyl choline, cholesterol esters and triglycerides from the PLOA-treated Ehrlich tumor cells differed markedly from that of the corresponding lipids from the control tumor cells.

The effects of exposure to NO or NO2 and an antigen on the breathing curve pattern in guinea pigs

Abstract The effect of NO and NO2 of inducing an asthmatic breathing difficulty following inhalation of albumin of different species and the effect on the hypersensitivity toward acetylcholine in the respiratory tract were investigated to study the relation between asthma and NO, NO2. Two experimental groups, the group exposed to NO (average 5.02 ppm) and the group exposed to NO2 (average 5.00 ppm) were prepared. The exposures to NO or NO2 gas (30 min) and, after 20 min, the albumin solution spray were repeated ten times, twice a week. For these exposures, breathing curves were continuously autorecorded with a body plethysmograph to ascertain the intensity of the asthmatic respiratory difficulty. Comparison showed that animals with stronger patterns of asthmatic dyspnea were greater in number when exposed to NO or NO2 and albumin (NO or NO2 group) than when exposed only to albumin (control group). Following all exposures, each group was expos d to an acetylcholine spray of the same concentration. In the case of the NO, NO2 groups, an increase in the susceptibility of the airway tract to acetylcholine could be observed.

Inhibition of acid esterase in rat liver by 4,4′-diethylaminoethoxyhexestrol

The effect of 4,4′-diethylaminoethoxyhexestrol (DH) on acid esterase in rat liver was studied in vivo and in vitro. The acid esterase activity in the livers of rats treated with 0.125% DH for 1 week was found to decrease more than 60% as compared with that in untreated rats. The addition of DH to the incubation medium caused considerable inhibition of the acid esterase activity in lysosome from untreated rat liver, and the inhibition type appears to be noncompetitive. The acid lipase activity in rat liver lysosome was also inhibited by DH. Some antihistamic agents and chloroquine also inhibited the acid esterase activity in rat liver lysosome.

Procedure for evaluating changes in respiratory symptoms of experimentally asthma‐induced guinea pigs by a personal computer

An automated system was developed for evaluating changes in respiratory symptoms in guinea pigs over a long period with a personal computer. The data on breathing curves obtained with a body plethysmograph were analyzed to determine respiratory rate, expiration/inspiration ratio, ventilation ratio, and other parameters. With this system, respiratory changes in guinea pigs, such as increase or decrease of respiratory rate, expiration/inspiration ratio, and ventilation ratio, and death of animals could be easily observed. Investigation of delayed respiratory response to Candida albicans in sensitized guinea pigs and of the effects of SO2 or NO2 exposures on its response was carried out using this system. Respiratory changes in delayed respiratory response were mostly increased respiration rate and succeeding expiratory prolongation being noted just before death. In the influences of SO2 or NO2 exposure on delayed respiratory response, increase of respiratory rate in NO2 and expiratory and inspiratory prolongation in SO2 were found. This system should prove useful for evaluating changes in respiratory symptoms due to toxic agents, medicines, and air pollutants in small animals.