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Biomedical subjects

T Kasama

Publications and source records attributed to T Kasama.

At least 163 records · Page 9Linked to original sources

[Effects of oxybutynin on the cardiovascular system in dogs].

The effects of oxybutynin, an anticholinergic and antispasmodic agent, on the cardiovascular system were studied in comparison with those of atropine in anesthetized dogs. Oxybutynin (0.1-10 mg/kg, i.v.) caused a transient hypotension, tachycardia, increases in femoral, stomach, mesenteric and common carotid arterial blood flows and a decrease in renal arterial blood flow. Atropine (0.1-10 mg/kg, i.v.) caused a stronger and more prolonged hypotension with bradycardia, accompanied by weaker blood flow changes than those by oxybutynin. In open-chest dogs, oxybutynin caused increases in cardiac output and coronary sinus outflow and decreases in heart rate and left ventricular pressure. The agent augmented dLVP/dt/P at doses up to 3 mg/kg, i.v., but reduced it at 10 mg/kg, i.v. Atropine caused stronger cardiosuppressive responses than those of oxybutynin. Coronary sinus outflow was decreased by atropine, unlike in the case of oxybutynin. The pressor responses of norepinephrine, epinephrine and tyramine were potentiated by pretreatment with oxybutynin (15 mg/kg, i.v.). However, pressor or depressor responses induced by histamine, isoproterenol, serotonin and DMPP were unaffected by oxybutynin. Intraarterial injections of oxybutynin, atropine and papaverine caused femoral and renal arterial vasodilations dose-dependently, in the following order of potency: papaverine greater than oxybutynin greater than atropine. In the isolated blood-perfused canine papillary muscle preparation, oxybutynin and atropine caused a negative inotropic action, whereas papaverine caused a positive inotropic action. From the above results, it is suggested that oxybutynin has milder cardiosuppressive and hypotensive effects than atropine in terms of potency and duration of action, and in addition, oxybutynin has a vasodilating action probably ascribable to its anticholinergic and antispasmodic actions.

Acetylcholine↗

Determination of sulfated and nonsulfated bile acids in serum by mass fragmentography.

A Sep-Pak C18 cartridge was used for purification of bile acids from serum. Three kinds of deuterium labeled internal standards were required for accurate measurement of individual sulfated and nonsulfated bile acids. These internal standards were added to the serum before its application to the cartridge. Separation of sulfated and nonsulfated bile acids was performed on piperidinohydroxypropyl Sephadex LH-20 column chromatography. The nonsulfate fraction was submitted to alkaline hydrolysis, and the sulfate fraction to solvolysis followed by alkaline hydrolysis. Each fraction was converted to the hexafluoroisopropyl-trifluoroacetyl derivatives and quantitated by mass fragmentography. The recovery of each bile acid sulfate was quite satisfactory. In fasting healthy subjects the mean of total nonsulfated bile acids in serum was 1.324 micrograms/ml, and that of total sulfated bile acids was 0.450 micrograms/ml. Sulfated lithocholic acid comprised a large part of sulfated bile acids in healthy subjects.

Bile Acids and Salts↗

Occurrence of 2-O-acyl galactosyl ceramide in human and bovine brains.

Ester cerebrosides isolated from whale brain were demonstrated to be a mixture of 6-O-acyl, 2-O-acyl, 4-O-acyl, and 3-O-acyl galactosyl ceramides in that order of content (Yasugi, E., et al. (1982) J. Biochem. 91, 1121-1127). However, the existence of 2-O-acyl and 4-O-acyl galactosyl ceramides has not been reported for other mammalian brains. In the present work, ester cerebrosides isolated from bovine and human brains were examined in order to determine whether the above-mentioned substitution is only present in whale brain or also present in other mammalian brains. For determining the substituted positions of the acyl group on the galactose moiety, free hydroxyl groups of ester cerebrosides were protected with dihydropyran, deacylated by mild alkali treatment, and then subjected to permethylation. Finally, the methylated galactitol acetates obtained by hydrolysis and reduction were analyzed by gas chromatography and gas chromatography/mass spectrometry. By these procedures, ester cerebrosides obtained from bovine and human brains were demonstrated to be not only 6-O-acyl and 3-O-acyl galactosyl ceramides but also 2-O-acyl and 4-O-acyl galactosyl ceramides similar to those of whale brain.

Animals↗

Branched chain fatty acids in phospholipids of guinea pig Harderian gland.

Fatty acid compositions of phosphatidyl ethanolamine and phosphatidyl choline extracted from the guinea pig Harderian gland were examined by gas chromatography and gas chromatography-mass spectrometry. Oleic acid was the major component of both phospholipids, but a large amount of saturated branched chain fatty acids was found: 34.5% in phosphatidyl ethanolamine, and 42.9% in phosphatidyl choline. On the other hand, linolenic and arachidonic acids were not found in these phospholipids. At the 1-position of phosphatidyl choline and phosphatidyl ethanolamine, 54.3% and 40.9% of fatty acids, respectively, had methyl branches. These methyl branches were located at the even-numbered carbon atoms. Branched chain fatty acids were also found at the 2-position of both lipids: 36.2% in phosphatidyl choline and 31.2% in phosphatidyl ethanolamine. The fatty acids of phosphatidyl ethanolamine and phosphatidyl choline from liver, cerebrum, cerebellum, erythrocytes, and plasma of the same animal were also analyzed. Saturated and unsaturated fatty acids, including arachidonic acid, were the major components. Branched chain fatty acids were also found in these lipids, but in very small amounts.

Animals↗

The characterization of 2,3-alkanediol diacyl esters obtained from the Harderian glands of Mongolian gerbil (Meriones unguiculatus).

A major lipid class in the Harderian glands of the Mongolian gerbil was investigated. The IR and 1H-NMR spectra suggested that it was a wax-like compound. Fatty acids present were capric, lauric, myristic, palmitic, stearic, arachidic, and behenic acids in ratios of 3.0%, 16.3%, 16.5%, 29.5%, 5.1%, 16.4%, and 9.8%, respectively. Odd-numbered, branched chain and unsaturated fatty acids were not present in large amounts. The structure of the alcohol moiety was elucidated to be 2,3-alkanediol with carbon chain lengths from C12 to C22 by GC-MS of the TMS and isopropylidine derivatives. Lemieux-von Rudloff oxidation of these alcohols confirmed the 2,3-diol structure, giving fatty acids two carbon units shorter.

Animals↗

Studies on the antigenicity of glucagon.

In order to test the safety of glucagon (GG), the immunogenicity of GG was studied in rabbits and guinea pigs. Any sensitization, as revealed by anaphylactic shock, Arthus reaction, passive cutaneous anaphylaxis (PCA) or radioimmunoassay, was not demonstrated in animals immunized with GG alone. The anti-GG antibodies were detected by PCA and radioimmunoassay in two of the five animals immunized with GG mixed with Freund's complete adjuvant. Anti-GG IgE antibody production in mice was found in one of the ten mice given 570 micrograms and three of the six mice given 1,000 micrograms of GG with aluminum hydroxide gel (Alum), but other doses of GG with Alum produced no IgE antibody. These results indicate that the antigenicity of GG is very weak.

Anaphylaxis↗

[Pharmacological action of bromazepam suppository].

Differences between the pharmacological effects of bromazepam given by oral and rectal administration were investigated in mice and rats. 1) Bromazepam dose-dependently prolonged the sleeping time induced by thiopental-Na, ethanol and ether by both administration routes. 2) The analgesic action of bromazepam was recognized by the hot-plate method and the algolytic test. In the hot-plate test, analgesic actions of morphine and pentazocine were potentiated by bromazepam in a dose of 0.5 mg/kg by both routes. 3) The muscle relaxant effect of bromazepam administered rectally was more potent than that administered orally in the inclined screen test and the rotarod test. This effect of bromazepam by rectal administration was approximately 2 times as potent as that by oral administration. 4) Bromazepam inhibited the convulsion induced by maximum electric shock, pentylenetetrazol and picrotoxin. In pentylenetetrazol-induced convulsion, the inhibitory effect of bromazepam administered rectally was 2 times as potent as that administered orally. In the other convulsion test, no significant differences between oral and rectal administration could be recognized. 5) Hyperemotionality and muricide (mouse-killing behaviour) of rats with bilateral olfactory bulb ablations (OB rat) were reduced by oral and rectal administrations of bromazepam in a dose-dependent manner. The effects by rectal administration were more potent than that by oral administration. Bromazepam was approximately 20 times as potent as diazepam administered by the same route. Fighting behaviour in mice subjected to footshock was suppressed by rectal administration of bromazepam, and this effect was as same as that by oral administration. 6) The rate of lever pressing response in the lateral hypothalamic self-stimulation test in the Skinner box was markedly increased by rectal administration of 0.2 mg/kg bromazepam. 7) Methamphetamine-induced hyperactivity of mice was significantly suppressed only by bromazepam administered rectally in a dose of 5 mg/kg. 8) The falling effect of bromazepam on body temperature in normal rats was the same in both administration routes and was dose-dependent. From these data, significant differences of the pharmacological effects between oral and rectal administration of bromazepam were recognized in the duration of action and, in part, potencies; and therefore, rectal administration of bromazepam may be a useful dosage form for clinical use.

Administration, Oral↗

Serum bile acid profiles in cerebrotendinous xanthomatosis.

Non-sulfated bile acid concentrations in sera of 10 cases of cerebrotendinous xanthomatosis (CTX) were determined by mass fragmentography. Total bile acid (TBA) in serum was 0.492 +/- 0.436 microgram/ml (mean +/- SD) which was significantly lower than that (1.481 +/- 0.571) in healthy control sera. Cholic acid was 0.342 +/- 0.291 microgram/ml and was the dominant bile acid, which constituted 69.5% of TBA in serum. Chenodeoxycholic acid was 0.111 +/- 0.133 microgram/ml being a minor component in CTX sera, although it was the major bile acid in healthy control sera. Other bile acids such as deoxycholic acid, lithocholic acid and ursodeoxycholic acid were scarcely detected. Subnormal TBA level and deranged bile acid composition in CTX sera may reflect the defect of bile acid biosynthesis in CTX patients. Determination of serum bile acid may be useful in the diagnosis of CTX.

Adult↗

Occurrence of 2-O-acyl galactosyl ceramide in whale brain.

Four glycolipids (Fr. I, II, III, and IV) were isolated from whale brain and three (Fr. I, II, and III) of them were demonstrated to be galactosyl ceramide combined with fatty acid by ester linkage. Fr. IV was shown to be a monoalkyl monoacyl galactosyl glycerol. For determining the substituted position of the acyl group on the galactose moiety, free hydroxyl groups of ester cerebrosides were protected with dihydropyran, deacylated by mild alkali treatment, and then subjected to permethylation. Finally, the methylated galactitol acetates obtained by hydrolysis and reduction were detected by gas chromatography and identified by gas chromatography-mass spectrometry. By this procedure, Fr. I was shown to be an acyl ester of kerasine, with the ester group at the 6-position of galactose. Fr. II and III were demonstrated to be acyl esters of phrenosine, in which the acyl groups were attached to the 6- and 2-position of the galactose, respectively. While the ester-linked acyl group of Fr. I, II, and III was composed of only normal fatty acids, predominantly palmitic acid, and the amide-linked fatty acids showed a heterogeneous composition of normal and hydroxy fatty acids, C16 to C24.

Animals↗

Effects of ortho-iodo-sodium benzoate (OISB) on oxygen-hemoglobin affinity and its relation to plasma concentrations in dogs.

Effects of ortho-iodo-sodium benzoate (OISB) on oxygen-hemoglobin affinity were studied in unanesthetized beagles with simultaneous measurement of its plasma concentrations. Oxygen-hemoglobin affinity changes correlated well with the plasma concentrations of the drug. Intravenous administration of 100 mg/kg of OISB increased P50 significantly from the control value of 28.6 +/- 0.8 mmHg to 29.5 +/- 0.7 mmHg and 30.0 +/- 0.5 mmHg, 5 min and 30 min after the infusion, respectively. P50 gradually decreased thereafter, and after 1 hr period, elevation was no longer significant. Administration of 200 mg/kg of OISB caused a significant increase in P50 from the control of 29.3 +/- 0.3 mmHg to 30.5 +/- 0.4 mmHg, 31.1 +/- 0.3 mmHg, 31.1 +/- 0.3 mmHg and 30.5 +/- 0.5 mmHg, at 5 min, 30 min, 1 hr and 3 hr, respectively. P50 elevation declined thereafter to control levels. Plasma concentrations of the drug reached its highest level 5 min after the administration and declined gradually thereafter. All significant elevations of P50 were accompanied by the plasma concentrations of the drug more than 200 micrograms/ml. Biological half-life of the drug was found to be about 5.5 hr.

Animals↗

Abnormalities in cerebral lipids and hepatic cholesterol glucuronide of a patient with GM1-gangliosidosis type 2.

The brain tissue of a patient with GM1-gangliosidosis Type 2 showed an abnormal distribution pattern of lipids, that is, a marked increase in GM1-ganglioside, asialo-GM1 and cholesterol ester, a significant increase of glucosylceramide, lactosylceramide and asialo-GM2, and a decrease in galactocerebroside and sulfatide. On the other hand, the liver tissue showed a normal pattern of glycolipids, that is, the presence of normal amounts of glucosylceramide, lactosylceramide, globotriaosylceramide, globoside, hematoside (GM3) and GD3. However, it was found that the patient's liver contained a larger amount of cholesterol glucuronide than normal liver and that it was present only in the liver and not in the other tissues. This represents the first report of elevated cholesterol glucuronide in liver of GM1-gangliosidosis.

Brain↗

Antigenicity of desamido-insulin and monocomponent insulin.

No consensus about the antigenicity of monocomponent insulin has yet been reached. We have therefore administered different insulin preparations to rabbits and rats to determine IgG and IgE antibody production. The preparations used were porcine monocomponent insulin, conventional bovine and porcine insulin powders, porcine b-component and synthesized porcine mono-desamido-insulin and hexa-desamido-insulin. In rabbits, porcine b-component was the most antigenic preparation, followed by conventional bovine and porcine insulins. No antibody production was observed with the other preparations. In rats the 60 h passive cutaneous anaphylaxis test showed virtually no insulin IgE antibody production in response to porcine monocomponent insulin. However, if porcine b-component or porcine hexa-desamido-insulin was employed both for sensitisation and as the challenging antigen, positive skin reactions were observed with demonstration of insulin IgE antibodies. Our results confirm the low antigenicity of the pharmaceutical preparation of porcine monocomponent insulin and suggest that porcine hexa-desamido-insulin and porcine b-component administration may result in the production of reagin-type antibodies.

Amino Acids↗

Quantitative determination of individual non-sulfated bile acids and sulfated lithocholic acid in serum by mass fragmentography.

Individual non-sulfated bile acids and sulfated lithocholic acid in serum were determined by mass fragmentography. A hexafluoroisopropyl ester-trifluoroacetyl derivative of bile acid was prepared by the method of Imai et al. (J. Chromatogr. 120, 181, 1976). Deuterium labeled deoxycholic acid was used as an internal standard monitoring at m/z 623. Lithocholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, and cholic acid were determined by monitoring the intensities of m/z 622, m/z 620, m/z 620, m/z 620, ad m/z 618, respectively. A serum sample of 200 microliters including 500 ng of internal standard was hydrolyzed with strong alkali, then acidified to pH 1 with 2N HCl under cooling on ice, and extracted with diethyl ether immediately. Ether extracts were derivatized without further purification. Besides this assay of non-sulfated bile acids, total serum lithocholic acid including the sulfated form was determined as follows: extraction was performed after mixing the acidified (pH 1 with 2 N HCl) hydrolysate with ether and incubation at 40 degrees C for 2 h. Bile acid peaks in the mass fragmentogram were not affected by other materials in these serum extracts. The average values of individual non-sulfated bile acids in sera from healthy fasting subjects (n=15) were as follows: lithocholic acid, 0.049 micrograms/ml; deoxycholic acid, 0.462 micrograms/ml; chenodeoxycholic acid, 0.671 micrograms/ml; ursodeoxycholic acid, 0.070 icrograms/ml; and cholic acid, 0.217 micrograms/ml. Total lithocholic acid (non-sulfated and sulfated) in sera was 0.166 microgram/ml.

Bile Acids and Salts↗

Simplified determination of cholestanol in serum by gas-liquid chromatography: biochemical diagnosis of cerebrotendinous xanthomatosis.

Cholestanol (5 alpha-cholestan-3 beta-ol) in human serum was determined by gas-liquid chromatography after removal by epoxidation of cholesterol which is present in amounts about 400 times those of cholestanol and disturbs the accurate determination of minor sterols in serum. Epicholestanol (5 alpha-cholestan-3 alpha-ol) was used as an internal standard. By this method the cholestanol content in sera of 7 patients with cerebrotendinous xanthomatosis was determined. The cholestanol levels in those sera were significantly higher than those of normal subjects and the present method proved to be useful in a biochemical diagnosis of cerebrotendinous xanthomatosis.

Cholestanols↗

Presence of asialo GM1 and glucosylceramide in the intestinal mucosa of mice and induction of fucosyl asialo GM1 by conventionalization of germ-free mice.

Two major neutral glycolipids of the intestinal mucosa were purified by a series of column chromatographies and the structures were determined to be glucosylceramide and asialo GM1 by gas liquid chromatography. The carbohydrate structure of asialo GM1 was also confirmed from the reactivity of the glycolipid to rabbit anti-asialo GM1 antibody by an enzyme linked-immunosorbent antibody. The ceramide portion of both glycolipids had an extremely hydrophilic nature and more than 90% of the ceramide was composed of phytosphingosine and alpha-hydroxy fatty acids. In the previous paper we reported that the induction of a fucolipid in the microvillus membrane of mouse intestinal mucosa by conventionalization was observed on monitoring the incorporation of radiolabeled fucose in vivo. A fucoglycolipid having the same mobility on an autoradiogram as the fucolipid labeled in vivo was produced by in vitro incubation of intestinal asialo GM1 and GDP-[14C]fucose with the mucosal homogenates. Moreover, asialo GM1 prepared from brain gangliosides exhibited a similar ability to accept fucose and it was converted to fucosyl asialo GM1 which moved faster than the product from intestinal asialo GM1. The difference is considered to be due to the ceramide composition. These results suggest that conventionalization can induce the fucosyl asialo GM1 in the microvillus membrane probably through the induction of fucosyltransferase. Understanding the molecular mechanism of interaction between the physiological flora and host is the matter of further study.

Animals↗

Studies on monocomponent insulin. V. pharmacokinetics of soluble insulin preparations using in situ animal model.

Pharmacokinetics of soluble monocomponent insulin preparation was examined by using an in situ experimental model of rabbits. Rabbits were laparotomized under anesthesia, and prepancreatic duodenal vein, splenic vein, and hepatic artery were ligated, and cannulae were inserted into the hepatic vein, portal vein, abdominal aorta, and renal vein. After administration of the monocomponent insulin preparation, blood was drawn periodically from each cannula, exogenous insulin level was measured, and kinetic parameters were calculated from the blood level curves from the arteries. The parameters obtained were disappearance rate constant (Kel) of 0.128 plus or minus 0.013 hr-1 and biological half-life (T1/2) of 5.50 plus or minus 0.49 min. Rate of insulin uptake by each organ was calculated from the difference in arterial and venous blood levels at each time period and values were 12% for the lever and 31% for the kidney. No definite uptake was found in the digestive tract. Relationship between the potency of insulin and blood levels suggested that the minimum effective blood level of this insulin preparation was 20 - 30 microU/ml.

Animals↗