検索

The purpose of this study was to determine the aerobic training intensity from the maximal and submaximal running exercise in 21 untrained adult men. To accomplish this, we evaluated the relationship between physiological (oxygen intake and heart rate) and physical parameters (running speed) of training intensity, and determined the training intensity at the submaximal exercise. Oxygen intake and heart rate were measured by a treadmill test. The maximal oxygen intake (VO2 max), and the aerobic threshold (AerT) and anaerobic threshold (AT) were measured to determine respiratory gas exchange. Running capacity was measured by a 12-min running and treadmill test. For the maximal exercise, there was a significant correlation (r = 0.88, P < 0.01) between VO2 max and 12-min running distance (speed). In addition, the oxygen intake and heart rate at AerT and AT in the submaximal exercise were linearly correlated with running speed. Three levels of training intensity at the submaximal exercise were termed: light, moderate, and heavy. Since AerT was the lower limit intensity and AT was the upper limit, we took the middle of their values as the moderate intensity. The end point for the determination of the training intensity at the submaximal exercise was estimated to be 85% VO2 max and 180 beats.min-1.

Cepharanthine, a biscoclaurine alkaloids which interact with biomembranes, has been found to inhibit platelet aggregation. The effects of this drug on morphological and physiochemical phenomena following collagen-induced platelet stimulation were investigated. In the presence of cepharanthine, stimulated platelets became spherical, but did not form pseudopoda , nor did they become aggregated. Physiochemical reactions such as accelerated oxygen consumption, release of membrane-bound Ca2+, release of Ca2+ into the extracellular medium and deporalization of the membrane potential were all inhibited by cepharanthine. Using D,L-dipalmitoyl phosphatidylcholine liposomes as the substrate, cepharanthine was shown to inhibit phospholipase A2 activity. These results suggest that the changes in the membrane following the interaction of collagen with its receptor are important for platelet activation. Cepharanthine may inhibits these membrane state changes, thus blocking all subsequent reactions.

In decerebrated cats the impulse discharges were detected by means of an unipolar microelectrode from a single inspiratory neuron in the respiratory centers, and the change in discharge produced by administration of stimulating, as well as depressant agents, was studied. The results were summarized as follows. 1) Inhalation of the air containing all. excess of carbon dioxide, as well as the air deficient of oxygen and the intravenous administration of a small dose of caffeine, aminocordine and lobeline produced a) a remarkable increase of frequency of impulses in the stage of constant frequency of the volley, b) a rapid increase of frequency of impulses in the stage of crescent frequency of the volley and c) a shortening of the duration of the volleys, as well as of silent periods. 2) In narcosis by a moderate dose of morphine, as well as in the recovery stage from apnea produced by over-ventilation, there were observed the phenomena which were exactly opposite to those described in 1). 3) It was concluded that a most essential sign by which one can discern whether the activity of the respiratory Genters is raised or depressed, is the changes of the frequency of impulses produced from an inspiratory neuron. The expense of this research was defrayed from the grant in aid of the Ministry of Education.