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Biomedical subjects

Y Isobe

Publications and source records attributed to Y Isobe.

At least 181 records · Page 10Linked to original sources
PubMed1981

Cytochemical demonstration of transferrin in the mitochondria of immature human erythroid cells.

The direct immunoperoxidase technique was employed to show the localization of transferrin in immature human erythroid cells. The present method is interesting in that use was made of a small marker (HRP-Fab' complex) and in that the endogenous peroxidase was blocked under a controlled condition- this ensured good structural preservation allowing electron-microscopic examination. Cytoplasmic transferrin was found not only in the micropinocytotic vesicles but also within the mitochondrial membrane. Similar findings were made in all the immature erythroid cells examined, each of which was in a different erythropoietic condition. Thus, it may be concluded that the present study provides morphological evidence for the endocytotic iron transport to the mitochondria.

Endocytosis↗
PubMed1980

Effects of heat acclimation of distance runners in a moderately hot environment.

Five distance runners (H groups) performed a 60 min bicycle exercise at a load of 60--70% VO2max in a moderately hot environment (Ta: 33.5 degree C, 60% RH). Following a period of heat acclimation with bench-stepping at a load equal to about 25--30% VO2max, in a hot environment (Ta: 45--50 degree C, 30--40% RH) for 9 days, the work test was repeated. Two control subjects (R) performed the same work tests with no heat acclimation. Heat acclimation increased performance time. Rectal temperature, mean skin temperature, heart rate, and Na+ concentrations in sweat were lower in H and, with one exception, sweat rate was higher after heat acclimation. All H subjects demonstrated that the linear relationship between sweat rate and rectal temperature was shifted to a lower temperature (threshold shift). This shift correlated with a lowering of resting rectal temperature. The magnitude of the reduction in those two temperatures due to heat acclimation was identical. The observed improvement of work performance in moderate heat following heat acclimation to a higher temperature is attributed to a more efficient thermoregulatory mechanism.

Acclimatization↗
PubMed1980

Diurnal variation of thermal resistance in rats.

Effects of photoperiod on heat resistance were studied in 88 rats by observing their survival times in a hot environment (42.5 degrees C). Prior to the experiments individual rats were exposed to a given heat (42.5 degrees C) at a definite time of day and a "predicted survival time" in a given heat in individual rats was obtained. Rats were then divided into eight groups (with nine rats in each group) so as to ensure intergroup homogeneity regarding their predicted survival time and were exposed to heat at different times of day (every 3 h) until they were exhausted. It was found that the heat resistance varied with the time of day. In the eight groups kept under a normal light-dark cycle (L, 0700-1900;D, 1900-0700), heat resistances were observed to be significantly higher in the light phase than in the dark phase. Lethal body temperature was not correlated with the heat resistance. In two other groups (n = 8) kept under conditions reversed from the normal lighting cycle, resistance was higher in the nighttime (corresponding to the light phase when the rats were kept in the reversed lighting cycle) than in the morning (corresponding to the dark phase), these changes being accompanied by a phase shift of the diurnal changes in body temperature.

Animals↗
PubMed1980

Relationships between hypothalamic catecholamines, blood pressure and body temperature in spontaneously hypertensive rats.

Rectal temperature, catecholamine contents in the hypothalamus, and blood pressure were measured in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). SHR had a significantly higher rectal temperature than WKY. Noradrenaline contents were lower in SHR than WKY. Noradrenaline was inversely correlated with the blood pressure and body temperature in SHR. In subgroups of SHR, differences in values of the parameters mentioned above were also observed.

Animals↗