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Biomedical subjects

I Takayanagi

Publications and source records attributed to I Takayanagi.

At least 253 records · Page 14Linked to original sources
PubMed1980

Effects of nonspecific smooth muscle relaxants on calcium-uptake by microsomal fraction and their inhibitory action in rabbit taenia coli.

Effects of nonspecific smooth muscle relaxants, papaverine and Aspaminol (1,1-diphenyl-3-piperidinobutanol hydrochloride) on Ca-uptake by a microsomal fraction and mechanical activity in the rabbit taenia coli were studied. Papaverine which inhibits cyclic AMP phosphodiesterase increased Ca-uptake by the microsomal fraction in a concentration of 10(-5) M but not in a concentration of 10(-4) M. Potentiation of Ca-uptake by papaverine is considered to be due to the increase of cyclic AMP as the results of the inhibition of phosphodiesterase. Aspaminol which is found to have little inhibitory action on phosphodiesterase activity inhibited Ca-uptake by the microsomal fraction. This inhibition by Aspaminol was abolished by the increase of Ca-concentration in the reaction medium. Non-competitive antihistaminic activity of Aspaminol was considerably reduced by an increase of external Ca-concentration, while the increase of external Ca-concentration slightly decreased antihistaminic activity of papaverine. Furthermore, contraction of KCl-depolarized taenia coli induced by CaCl2 was inhibited competitively by Aspaminol and noncompetitively by papaverine. These results suggest that Aspaminol competes with Ca ions at a surface site of muscle membrane concerned with Ca-uptake process, thus decreasing the supply of Ca ions to the contractile elements and that papaverine may have inhibitory actions on Ca-uptake by the microsomal fraction in addition to stimulatory action which seems to be mediated through cyclic AMP. These actions on Ca-uptake may induce smooth muscle relaxation.

Action Potentials↗
PubMed1980

Effects of nonspecific smooth muscle relaxants on glycogen phosphorylase activity in depolarized taenia caecum of guinea pig.

Effects of papaverine, Aspaminol (an antispasmodic drug), D-600, 2, 4-dinitrophenol and Ca ions on glycogen phosphorylase activity in the KCl-depolarized taenia caecum of guinea pig were tested. External Ca ions dose-dependently activated phosphorylase, indicating that Ca ions, which entered the smooth muscle cells, played an important role in the regulation of phosphorylase activity. Aspaminol, D-600 and removal of Ca ions from bath fluid inhibited phosphorylase activity. Since these treatments relaxed the taenia caecum, the decrease of phosphorylase activity after the treatments may be mainly due to the decrease of energy consumption. Papaverine and 2, 4-dinitrophenol induced an activation of phosphorylase which might be for replenishment of energy stores decreased by them.

Animals↗
PubMed1980

Effects of nonspecific smooth muscle relaxants on tissue concentrations of high energy phosphates and mechanical activity of normal polarized and depolarized intestinal smooth muscles from guinea pig.

Effects of nonspecific smooth muscle relaxants, an uncoupler and removal of Ca ions from physiological solution on the tissue concentrations of high energy phosphates, such as ATP and creatine phosphate (CP) and tension of the normal polarized and KCl-depolarized intestinal smooth muscles of guinea pig were studied. Decrease of CP-concentration induced by dinitrophenol (DNP; 10(-4) M) was accompanied by relaxation of the normal polarized and KCl-depolarized smooth muscles. DNP slightly (but significantly) decreased ATP-concentration in the normal polarized and KCl-depolarized smooth muscles. Application of papaverine ( 3 x 10(-5) M) relaxed the normal polarized taenia immediately but increased CP-concentration at 5 and 10 min and decreased the concentration at 20 min. When the depolarized smooth muscle was considerably relaxed by papaverine (3 x 10(10-5) M), there was little influence on the CP-concentration. After relaxation of the depolarized taenia as induced by papaverine had reached a maximal amplitude, CP-concentration decreased significantly. ATP-concentration was little influenced by papaverine in the normal polarized and KCl-depolarized muscles. Although the treatments with a synthetic antispasmodic drug, Aspaminol (3 x 10(-4) M), which was found to inhibit Ca-uptake by the intestinal smooth muscles, a Ca-blocker, D-600 (10(-6) M) and removal of Ca ions from physiological solution relaxed the polarized and depolarized smooth muscles, the tissue concentrations of CP and ATP increased. These phenomena are considered to be due to decrease of the intracellular Ca-concentration.

Adenosine Triphosphate↗
PubMed1980

Effects of nonspecific smooth muscle relaxants and Ca-blocker on Ca-release and Ca-binding in microsomal fractions from rabbit taenia coli.

Effects of nonspecific smooth muscle relaxants, papaverine (10(-4) M) and Aspaminol (1,1-diphenyl-3-piperidinobutanol hydrochloride, 10(-4) M), and Ca-blocker, D-600 (10(-6) M) on Ca-release and Ca-binding in the microsomal fractions of rabbit taenia coli were determined. The doses necessary to relax the K-depolarized taenia coli were determined. The doses necessary to relax the K-depolarized taenia coli maximally were used. Ca-binding in the microsomal fractions was inhibited by Aspaminol and D-600 and increased by papaverine in the concentration used. On the other hand, Ca-release from the Ca-incorporated microsomal fractions was inhibited by papaverine and Aspaminol but was not influenced by D-600. Changes observed in Ca-transfer may be related to relaxation of smooth muscle induced by the test drugs.

Animals↗
PubMed1980

Possible mechanisms of a new type of antispasmodic drug, BTM-1042(cis-(--)-2,3-dihydro-3-(4-methyl-piperazinyl)methyl-2-phenyl-1,5-benzothiazepin-4(5H)-one dihydrochloride).

A newly synthesized compound, BTM-1042 (cis-(--)-2,3-dihydro-3-(4-methyl-piperazinyl)methyl-2-phenyl-1,5-benzothiazepin-4(5H)-one dihydrochloride) depressed the twitch responses of the ileum from guinea pig to electrical stimulation at 0.1 Hz. This inhibitory action of BTM-1042 was not influenced by naloxone, a narcotic antagonist. BTM-1042 proved to be almost as active as atropine on electrically stimulated ileum. BTM-1042 also blocked muscarinic receptors but the potency was about 1/3 of that of atropine. The responses of the ileum of guinea pig to nicotine and 5-hydroxytryptamine also were inhibited by BTM-1042. However, BTM-1042 did not influence the release of transmitters from motor, sympathetic, nonadrenergic inhibitory (or purinergic nerve), noncholinergic excitatory nerves and responses of various smooth muscles mediated through drug receptors, except for the acetylcholine receptor. Spontaneous movement of the unanaesthetized rabbit stomach was dose dependently depressed by BTM-1042 (0.04--0.2 mg/kg, i.v.). The potency ratio for BTM-1042 relative to atropine was 7.4. BTM-1042 is apparently a new type of potent, antispasmodic drug.

Animals↗
PubMed1979

Effects of external calcium ions and strontium ions on interactions of isoprenaline and its competitive inhibitor with beta-adrenoceptors in the intestinal smooth muscle.

The effects were tested of Ca ions and Sr ions on interactions of isoprenaline and its competitive inhibitor with beta-adrenoceptors in the taenia caecum from the guinea pig. Ca ions were involved in the combination of isoprenaline with the beta-adrenoceptors but not involved in the combination of the competitive inhibitor with the beta-adrenoceptors. Sr ions could not substitute for Ca ions in the isoprenaline--receptor interaction.

Animals↗
PubMed1979

Inhibitory alpha-adrenergic action of phenylephrine in guinea pig taenia caecum.

Phenylephrine, a selective alpha-adrenergic stimulant, caused a maximal relaxation of the taenia from guinea pig caecum in the concentration of 10(-6) g/ml. Phenylephrine in this concentration did not influence intracellular cyclic AMP and cyclic GMP levels. Although phenylephrine abolished the spontaneous spike discharge, no change was detected in 45Ca-uptake and 45Ca-efflux on the tissue level after phenylephrine. Ca-uptake and Ca-release on the subcellular level were also not influenced by phenylephrine. In Ca free-solution phenylephrine inhibited the response to CaCl2. Phenylephrine increased 42K-efflux in the normally polarized taenia and also in the K-depolarized taenia.

Action Potentials↗
PubMed1979

Effects of smooth muscle stimulants on 1-isoprenaline-beta-adrenoceptor interaction in taenia from guinea pig caecum.

An increase in intracellular cyclic AMP levels induced by 1-isoprenaline (1-Iso) was significantly depressed in coexistence with BuTMA or histamine, but not with KCl or BaCl2. An analysis of steady state data for d,1-[3H]-isoprenaline binding to single cells of taenia from guinea pig caecum in the presence of histamine or KCl by Scatchard plots was performed. The affinity for 1-Iso for beta-adrenoceptor sites was decreased in the presence of histamine but not in the presence of KCl. These results suggest that the interaction of 1-Iso with the beta-adrenoceptors is interfered with by histamine and butyltrimethylammonium, for which the specific receptors were postulated, but not with KCl and BaCl2, nonspecific smooth muscle stimulants. These phenomena demonstrate the heterotropic negative cooperatively among the heterogeneous receptors.

Animals↗
PubMed1978

A difference in effects of physiological Ca2+ concentrations on activity of guanylate cyclase preparations obtained from the taenia caecum of guinea pig and from the longitudinal muscle of rat duodenum.

A cholinergic stimulant, butyltrimethylammonium bromide and serotonin increased the tissue levels of cyclic GMP in the taenia caecum of guinea pig but not those in the longitudinal muscle of rat duodenum. On the other hand, physiological Ca2+ concentrations enhanced the activity of a guanylate cyclase preparation obtained from the taenia caecum of guinea pig, while guanylate cyclase in the longitudinal muscle of rat duodenum was not influenced by Ca2+. The difference in the effects of the smooth muscle stimulants on the tissue levels of cyclic GMP in two different smooth muscles in attributed to differences in the properties of guanylate cyclase of smooth muscles.

Animals↗
PubMed1978

Effect of papaverine on Ca2+ uptake by a mitochondrial fraction isolated from rat uterine smooth muscle.

A mitochondrial fraction was isolated from rat uterine smooth muscle. The effect of papaverine (3 X 10(-6), 10(-5), 3 X 10(-5), 10(-4) M) on Ca2+ accumulation by the fraction was studied. The effect of papaverine was changed by using different substrates for Ca2+ accumulation. Papaverine inhibited the Ca2+ accumulation supported by glutamate plus ATP concentration-dependently. The Ca2+ accumulation supported by ATP alone was also inhibited. On the other hand, the Ca2+ accumulation supported by succinate and ATP was increased by papaverine. The effect was not concentration-dependent; papaverine (3 X 10(-5) M) was the most effective concentration for the effect with a shorter incubation (2 min).

Adenosine Triphosphate↗
PubMed1978

Relaxation of depolarized guinea pig taenia caecum induced by some antispasmodics.

Taenia isolated from the guinea pig caecum were used for the experiments. No inhibitory response of the depolarized taenia to isoprenaline was observed during the significant increase of cyclic AMP level. These observations suggest that the total tissue level of cyclic AMP is not an important determinant of relaxation in the depolarized taenia. Antispasmodics, such as papaverine, benactyzine and Aspaminol (1,1-diphenyl-3-piperidino-butanol hydrochloride) relaxed the depolarized taenia, while the depolarized taenia was not relaxed by concentrations of dibutyryl cyclic AMP sufficient to relax the polarized taenia. Ca uptake by the depolarized taenia was inhibited by papaverine, benactyzine and Aspaminol but not by isoprenaline and dibutyryl cyclic AMP. These results indicate that relaxation of the depolarized taenia induced by the antispasmodics used was mainly due to inhibition of Ca uptake.

Animals↗