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Biomedical subjects

N Kondo

Publications and source records attributed to N Kondo.

At least 559 records · Page 31Linked to original sources
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↗
PubMed1977

Endoscopic aspiration biopsy of the pancreas.

Preoperative endoscopic aspiration biopsies were performed on 51 patients with pancreatic lesions using either a duodenal or gastric fiberscope and a newly designed biopsy needle. The accuracy of this method in the diagnosis of carcinoma of the pancreas was 84.0%. Although there were three false-negative diagnoses, there were no false-positives. No complications that could be attributed to this procedure were encountered.

Adenocarcinoma↗
PubMed1976

Effect of a cholinergic stimulant on interaction of isoprenaline with beta-adrenoceptors.

The maximum contraction induced in taenia from the guninea pig caecum by a cholinergic stimulant, butyltrimethylammonium (BuTMA) was relaxed by papaverine (10(-4) M) but not by l-isoprenaline (5 X 10(-7) M). The concentrations used relaxed the taenia completely in the absence of BuTMA. BuTMA (10(-4) M) decreased the increase of cyclic AMP caused by isoprenaline but not that due to papaverine. Futhermore, photoinactivation of the beta-adrenoceptors by l-isoprenaline was not observed on the taenia contracted by BuTMA (10(-4) M). These results suggest that l-isoprenaline does nto interact with the beta-adrenoceptors in the taenie contracted by the high concentration of BuTMA.

Animals↗
PubMed1975

Difference between inhibitory actions of papaverine and dehydroepiandrosterone on the isolated guinea-pig ileum.

Dehydroepiandrosterone (DEA), a metabolite of steroid hormone in the urine, differed from papaverine in the mode of inhibitory action on the isolated guinea-pig ileum. Papaverine inhibited both phasic and tonic contractions induced by an agonist, while DEA inhibited the phasic contraction without apparent fatigue of the tonic phase. The main action of papaverine seems to be predominatly a metabolic inhibition similar to that of metabolic inhibitors, but the action of DEA could not be ascribed to that of metabolic inhibition. In the presence of papaverine or metabolic inhibitors the height of maximal contraction of an agonist tested by the cumulative method was greatly depressed and less than that by a single method. The longer the time involved in the cumulative doses, the lower was the maximal contraction.

Acetylcholine↗