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T Kawada

Publications and source records attributed to T Kawada.

At least 289 records · Page 16Linked to original sources
PubMed1987

Capsaicin, a pungent principle of hot red pepper, evokes catecholamine secretion from the adrenal medulla of anesthetized rats.

Using a direct monitoring system for catecholamine (CA) secretion into the adrenal vein, we have demonstrated that capsaicin (CAP) evokes CA secretion from the adrenal medulla of pentobarbital-anesthetized rats. A significant increase in epinephrine (E) secretion was seen in rats infused with CAP (200 micrograms/kg, i.v.) without a detectable lag after the infusion. Norepinephrine (NE) secretion evoked by CAP was fairly weak compared with E secretion. The secretion of E evoked by CAP was dose-amount dependent. The stimulation of E release by CAP was barely detectable at 20 micrograms/kg, half-maximal at 100 micrograms/kg, and maximal at 600 micrograms/kg. When CAP (200 micrograms/kg) was infused into rats, the weight-ratio of E to NE was significantly higher (47.6) than when acetylcholine (12.5 micrograms/kg) was infused (13.0). These results indicate that CAP can evoke CA secretion from the adrenal medulla of rats.

Acetylcholine↗
PubMed1987

Positive inotropic and chronotropic effects of trypsin and some other proteolytic enzymes in the guinea-pig heart.

1 In atrial preparations of the young guinea-pig (body weight 150-250 g), five proteolytic enzymes (trypsin, chymotrypsin, bacterial-Al-proteinase (nagarse), bromelain and kallikrein) produced concentration-dependent positive inotropic and chronotropic effects, while they exerted only minimal effects on the papillary muscle preparations. 2 To characterize the effects, further experiments were conducted in atrial preparations using trypsin. There was a strong tendency for tachyphylaxis: a second exposure to the same concentration of trypsin resulted in considerably smaller positive inotropic and chronotropic effects. The positive inotropic and chronotropic effects of this substance were not affected by propranolol (5 X 10(-7)M). However, an accumulation of cyclic AMP was observed and the positive inotropic and chronotropic effects were potentiated by aminophylline (10(-4)M) in association with an augmentation of the accumulation of cyclic AMP. In preparations partially depolarized with high K+ (22mM) medium (contractions ceased under this condition) trypsin 100 micrograms ml-1 reinstated the contraction. Treatment of the preparation with aprotinin (200 u ml-1) resulted in a strong inhibition of the positive inotropic and chronotropic effects. 3 Islet activating protein (IAP), a specific inhibitor of the 'inhibition specific' guanine nucleotide binding regulatory protein of the adenylate cyclase system, did not produce significant inhibition of the positive inotropic and chronotropic effects of trypsin, whereas it produced a complete inhibition of the negative inotropic and chronotropic effects of carbachol. 4. These results suggest that the positive inotropic and chronotropic effects ofproteolytic enzymes are intimately connected with the proteolytic activities through which adenylate cyclase is activated to produce an accumulation of cyclic AMP within the myocardium. The destruction of the 'inhibition specific' guanine nucleotide regulatory protein of the adenylate cyclase was not substantiated as a mechanism of activation of the adenylate cyclase.

Adenylate Cyclase Toxin↗
PubMed1987

Effects of bunitrolol on adrenergic and serotonergic receptors.

To assess the importance of anti-adrenergic and anti-serotonergic activities of bunitrolol for its efficacy as an antihypertensive and antianginal agent, effects of this substance on the binding of adrenergic and serotonergic agents to the respective receptors of the rat brain, rat heart, dog brain, and/or dog aorta were examined using the radioligand binding assay methods. In addition, the pA2 values of bunitrolol as an antagonist against the positive chronotropic and inotropic actions (beta 1-adrenoceptor) of isoproterenol were also determined by pharmacological methods using the isolated guinea pig atria. To assess the specificity, pA2 values were also obtained in the isolated trachea (beta 2-adrenoceptor) using isoproterenol as an agonist and in the isolated aorta from the guinea pig and the rat using phenylephrine as an agonist (alpha 1-adrenoceptor). A strong inhibition by bunitrolol of 3H-dihydroalprenolol (3H-DHA) binding to beta-adrenoceptors was observed, while the inhibition of 3H-prazosin binding to alpha 1-adrenoceptors, 3H-serotonin binding to 5HT1-receptors. 3H-p-aminoclonidine binding to alpha 2-adrenoceptors, and 3H-ketanserin binding to 5HT2-receptors were found to be very weak. The rank order of antagonistic potencies of bunitrolol against the adrenergic receptors as assessed with pA2 values were beta 1 greater than beta 2 much greater than alpha 1. From these two different types of experiments, it is clear that the antihypertensive and antianginal effects of bunitrolol are mainly due to its beta-blocking actions, with the alpha 1-blocking action of this drug playing a minor role.

Animals↗
PubMed1986

Bronchial artery aneurysm.

Two patients with bronchial artery aneurysm were surgically treated. One patient had a saccular aneurysm in the root of the left bronchial artery, and the other had a mediastinal as well as an intrapulmonary aneurysm, rupture of the latter of which had resulted in massive hemoptysis. Twelve reports of bronchial artery aneurysm have appeared in the literature to date. Those of mediastinal location frequently have symptoms mimicking dissecting aortic aneurysm, whereas their intrapulmonary counterparts usually are manifested by hemoptysis. Although its etiological process remains to be elucidated, this rare entity should be recognized in the clinical practice.

Adolescent↗
PubMed1986

Resistance to cefsulodin and gentamicin in Pseudomonas aeruginosa strains in five areas of Japan between 1980 and 1983.

The activities of cefsulodin and gentamicin against Pseudomonas aeruginosa isolated from clinical specimens from five hospitals in different geographical areas of Japan, from 1980 to 1983, were compared in vitro. The incidence of resistant strains was higher for gentamicin. In 1982 the sensitivity to both drugs decreased from 1980 and 1981 levels, largely because of the isolation of numbers of cefsulodin-gentamicin cross-resistant bacteria from three of the five hospitals. In 1983, the incidence of resistant strains was similar to that in 1982. This linked cefsulodin-gentamicin resistance may have been selected by the use of the cephalosporins, cefmenoxime, cefoperazone, cefotaxime, ceftizoxime and latamoxef, which had been prescribed extensively in the hospitals where cross-resistance was encountered. Although cefsulodin-resistant strains of P. aeruginosa have increased since 1982, the in-vitro activity of cefsulodin in 1983 remained greater than that of these third-generation cephalosporins.

Cefsulodin↗
PubMed1986

Effects of capsaicin on lipid metabolism in rats fed a high fat diet.

Effects of capsaicin, a pungent principle of hot red pepper, were studied in experiments using male rats fed a diet containing 30% lard. Capsaicin was supplemented at 0.014% of the diet. The level of serum triglyceride was lower when capsaicin was present in the diet than when it was not. Levels of serum cholesterol and pre-beta-lipoprotein were not affected by the supplementation of capsaicin. The perirenal adipose tissue weight was lower when capsaicin was present in the diet than when it was not. Hepatic enzyme activities of glucose-6-phosphate dehydrogenase and adipose lipoprotein lipase were lower in rats fed the 30% lard diet than in those fed a nonpurified diet. Activities of these two enzymes were higher when capsaicin was added to the diet than when it was not. Hepatic acetyl-CoA carboxylase, beta-hydroxyacyl-CoA dehydrogenase, and adipose hormone-sensitive lipase activities were not affected by capsaicin feeding. Lipid absorption was not affected by the supplementation of capsaicin. The perirenal adipose tissue weight and serum triglyceride were decreased as the level of capsaicin in the diet increased up to 0.021%. These results suggest that capsaicin stimulates lipid mobilization from adipose tissue and lowers the perirenal adipose tissue weight and serum triglyceride concentration in lard-fed rats.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1986

Capsaicin-induced beta-adrenergic action on energy metabolism in rats: influence of capsaicin on oxygen consumption, the respiratory quotient, and substrate utilization.

The mode of action of capsaicin on energy metabolism was investigated in rats. The oxygen consumption was higher when capsaicin (6.0 mg/kg) was intraperitoneally injected than when it was not injected. The respiratory quotient (R.Q.) increased and then decreased after the administration of capsaicin. The levels of serum glucose and immunoreactive insulin rapidly increased after the administration of capsaicin. Also, liver glycogen rapidly decreased, in contrast to the serum glucose concentration which rapidly increased. The serum-free fatty acid level gradually increased after the administration of capsaicin. These alterations in energy metabolism on the administration of capsaicin were similar to those in the metabolism of epinephrine, and were specifically inhibited by various beta-adrenergic blockers. On the other hand, the alterations were not affected by pretreatment with alpha-adrenergic or ganglion blockers. These results suggest that the mode of action of capsaicin on the enhancement of energy metabolism in rats comprises a direct (as an agonist) and/or an indirect (via catecholamine) beta-adrenergic action. Therefore, it was speculated that the adrenergic action of capsaicin resulted, at least in part, in a decrease in the perirenal adipose tissue weight and serum triglyceride concentration in rats fed a high fat diet supplemented with capsaicin (T. Kawada et al., J Nutr 116:1272-1278, 1986).

Adrenergic beta-Agonists↗
PubMed1986

Plasma antithrombin III, alpha 2-plasmin inhibitor and plasminogen activities in cases of various liver diseases.

alpha 2-PI, a coagulation factor, and AT III and PLG, fibrinolytic factors, are all glycoproteins synthesized in the liver, and their half-lives are as short as two to three days. Therefore, we assumed that determination of their plasma activities would be meaningful as a liver function test. We determined these three factors in 900 patients with various liver diseases and investigated their relation to serum biochemical data and differences in their activities among the diseases. Parameters in which all three factors were significantly correlated (magnitude of gamma greater than or equal to 0.5) were serum ALB, CHE and PT, indicating that the factors were suitable for the examination of liver function, particularly its reserve capacity. The activities of the three factors were significantly decreased (p less than 0.001) in the presence of acute hepatitis, chronic active hepatitis, fulminant hepatitis and liver cirrhosis. Compared with patients with compensated liver cirrhosis, those with decompensated liver cirrhosis exhibited significant decreases in the three factors. Among chronic hepatitis cases, the active type showed a more significant decrease in ATIII alone than the inactive type. These results indicate that determination of the three factors is very useful for the differential diagnosis and follow-up study of various liver diseases.

Adult↗