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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 739 records · Page 41Linked to original sources

Physiological study of the human mesotubarium ovarica.

The human mesotubarium ovarica has been shown to contain bundles of smooth muscle cells. Its contractility at various phases of the menstrual cycle was studied in vitro in 51 tissue strips obtained at laparotomy. The strips obtained at the ovulatory phase showed the greatest spontaneous contractile activity as well as the greatest contractile response to norepinephrine, acetylcholine, and prostaglandin F2 alpha. This corresponds to the increased contractility of the ovary at this phase of the cycle. It is suggested that these contractile actions may, under the influence of chemical transmitters, play a role in ovum pick-up by the tubal fimbria at ovulation.

Acetylcholine↗

Cryoactivation of inactive renin in human plasma.

The mechanism of the increase in renin activity in human plasma which had been kept -5 degrees C for 4 days (cryoactivation) was investigated. From the results of clinical studies, it is likely that the controling mechanism of inactive renin has something in common with that of active renin. The experimental data showed that the increase in renin activity of human plasma by cryoactivation was closely correlated to the increase obtained by incubation with trypsin (r = 0.88, p less than 0.001, n = 10). Soybean trypsin inhibitor, aprotinin and di-isopropylfluorophosphate (DFP) inhibited cryoactivation, indicating that the cryoactivation is due to the action of a trypsin-like serine enzyme. Trypsin which had no effect on plasma renin activity in the presence of the same amount of soybean trypsin inhibitor at 37 degrees C, activated the renin activity during cold incubation, suggesting that the dissociation of the trypsin-inhibitor complex may have taken place at a low temperature. Endogenous trypsin inhibitor is also likely to lose its affinity to endogenous trypsin-like enzyme at a low temperature.

Cold Temperature↗

Cryoactivation of plasma renin.

1. The mechanism of increased renin activity after human plasma had been kept at -5 degrees C for 4 days (cryoactivation) was investigated. 2. The increase in renin activity of human plasma by cryoactivation was closely correlated to the increase obtained by incubation with trypsin (r = 0.88, P less than 0.001, n = 10). 3. An inhibitor of thiol enzyme, N-ethylmaleimide did not inhibit cryoactivation. 4. Soyabean trypsin inhibitor and di-isopropylflurophosphate (DFP) inhibited cryoactivation, suggesting that the cryoactivation may be due to the action of a trypsin-like serine enzyme. 5. In an experiment in the rat haemorrhagic shock caused parallel and cryoactivated plasma, the renin activity being about two times higher in the latter. No significant differences were found in the concentrations of renin and renin substrate between the non-cryoactivated and cryoactivated plasma samples. 6. The results may indicate that a destruction of an inhibitor of the renin-renin substrate reaction is responsible for the increase of renin activity after exposure of rat plasma to low temperature. A trypsin-like enzyme in plasma might have destroyed the inhibitor during this procedure.

Animals↗

Reconstruction of the superior vena cava in a patient with a thymoma.

Surgical treatment was attempted in a 71-year-old man who had superior vena caval syndrome caused by incomplete obstruction of the superior vena cava with a thymoma. Using a temporary internal shunt, the superior vena cava was almost entirely resected together with the tumor and reconstructed by autogenous venous grafts. Patency of the reconstructed vein was proved by angiography one year after the operation. He has been asymptomatic for 15 months after surgery.

Aged↗