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Biomedical subjects

T Tamada

Publications and source records attributed to T Tamada.

At least 235 records · Page 13Linked to original sources

Lack of release of human chorionic gonadotropin by gonadotropin-releasing hormone.

The effects of either single injection or continuous infusion of synthetic Gn-RH on plasma hCG levels were studied in 5 pregnant women (14-38 week gestation). No definite increase of hCG level was seen in all the cases studied. In view of large dosages of Gn-RH used in this study in comparison with its minimum effective dose for the pituitary gonadotropin release, Gn-RH seems unlikely to play a role in hCG secretion during human pregnancy.

Chorionic Gonadotropin↗

[Findings in the gastric mucosa and gastric secretion in rats treated with methyl O-(4-hydroxy-3-methoxycinnamoyl)reserpate (CD-3400) and reserpine derivatives].

CD-3400 developed by Nippon Chemiphar Co. Ltd., is a new antihypertensive agent belonging to the class of rauwolfa alkaloids. Influence of the agent on gastric mucosa, healing process of acetic acid-induced gastric ulcer and gastric juice in rats was investigated and compared with effects of reserpine and rescinnamine. CD-3400-induced gastric lesions were fewer in number than those produced with reserpine and rescinnamine in fasted rats. After a three day treatment of CD-3400 to fed rats, however, there were few gastric lesions, while reserpine- and rescinnamine-induced gastric lesions were aggravated to a greater extent that when a single administration was given to fasted rats. Influence of CD-3400, reserpine and rescinnamine on the healing process of acetic acid-induced ulcer was insignificant, but treatment with high doses of reserpine and rescinnamine resulted in death. Pretreatment with CD-3400 and reserpine produced a decrease in gastric acid and K+, and an increase in Na+. Repeated administration of reserpine for 5 days resulted in a decrease of both gastric volume and acid, while such was not seen with CD-3400. Treatment with anticholinergic agents such as atropine sulfate and atropine methylbromide inhibited CD-3400- and reserpine-induced gastric lesions. From these results, it would appear that cholinergic factors play a role in the pathogenesis of CD-3400-induced gastric lesions, as in the case with reserpine, and that the responses of these lesions to reserpine and CD-3400 correlate with changes of ionic fluxes in gastric juice.

Acetates↗

[Effects of methyl O-(4-hydroxy-3-methoxycinnamoly)reserpate (CD-3400) on the peripheral nervous system: especially on the smooth muscle organs].

Effects of methyl O-(4-hydroxy-3-methoxycinnamoyl) reserpate (CD-3400), a new antihypertensive agent, on the peripheral nervous system in mice, rats and guinea pigs were investigated and compared with effects of reserpine and rescinnamine. Oral administration of CD-3400 in doses from 40 to 320 mg/kg revealed a miotic action and such was weaker than that seen with reserpine and rescinnamine. The intestinal propulsion in mice was accelerated by pretreatment with reserpine, but no so with CD-3400. In isolated guinea pig vas deferens, CD-3400 at a concentration of 1 X 10(-5) M inhibited on norepinephrine-induced contraction non-competitively. However, in insolated rat vas deferens pretreated with CD-3400 (1 mg/kg, i.p.) for 5 days, norepinephrine-induced contraction was potentiated and this effect was weaker than that seen with reserpine and rescinnamine. In isolated rat vas deferens pretreated with CD-3400 for 1, 2 and 5 days,, the contraction induced by tyramine (3 X 10(-5)M) was significantly inhibited. The effect was qualitively similar to those of reserpine and rescinnamine. The intravenous administration of these three rauwolfia alkaloids in doses of 1, 2 and 4 mg/kg had no effect on the spontaneous movement of rat uterus. In isolated rat uterus pretreated with CD-3400, no significant effect was observed on oxytocin- and isoproterenol-induced responses. The peripheral actions of CD-3400 are attributed to a deterioration in the function the sympathetic nerve resulting in depletion of catecholamine stores. Efect of CD-3400 were slightly weaker than those of reserpine and rescinnamine.

Animals↗