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Biomedical subjects

M Maruoka

Publications and source records attributed to M Maruoka.

44 records · Page 3Linked to original sources

Binding of dihydrotestosterone, R 1881 and R 5020 in cytosols from normal, benign hypertrophic and cancerous human prostates.

The binding of dihydrotestosterone, R 1881 and R 5020 was examined in cytosols of normal, benign hypertrophic and cancerous tissues of the human prostates. Almost all samples obtained by open operation showed high affinity binding to these ligands. Dissociation constants of the binding to these ligands were approximately 10(-9) M irrespective of the pathological state of the prostates. Maximum binding sites for dihydrotestosterone seemed to be greater in normal tissues than in the pathological ones. However, maximum binding sites for R 1881 and R 5020 were not significantly different among the normal and pathological prostates examined in the present study. Moreover, some correlation was observed between the maximum binding sites for R 1881 and those for R 5020. The samples resected by TUR seemed to be inadequate for analyses of androgen binding.

Cytosol↗

Potentiation by dipyridamole of the inhibition of guinea-pig ileum twitch response caused by adenine derivatives.

The inhibition actions of adenosine and adenine nucleotides, such as ATP, AMP and cyclic AMP, on contractions of guinea-pig from ileum induced by transmural stimulation were potentiated by dipyridamole, whereas those of inosine, morphine and tetrodotoxin were not affected. Tritium activity, accumulated during incubation of the ileal segments with [3H]adenosine, was reduced by dipyridamole. The adenosine added was degraded to inosine and then hypoxanthine during incubation, with the ileal segments, thereby restoring the twitch response of the ileal segments. In the presence of dipyridamole, the degradation of adenosine and the recovery of the twitch response was retarded. Thus, dipyridamole may potentiate the inhibitory actions of adenosine and adenine nucleotides on the twitch response of the ileum by inhibiting both the accumulation and the degradation of adenosine.

Adenine Nucleotides↗