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H Sei

Publications and source records attributed to H Sei.

40 records · Page 3Linked to original sources
PubMed1990

Concurrent on-line sampling of melatonin in pineal microdialysates from conscious rat and its analysis by high-performance liquid chromatography with electrochemical detection.

Dynamic changes of melatonin in microdialysates from the pineal gland of a freely moving rat were repeatedly determined by using on-line high-performance liquid chromatography with electrochemical detection. The detection limit for melatonin, ca. 5 pg, was well below that achieved with other systems. We observed a drastic increase of extracellular pineal melatonin during the transitional phase from the light period to the dark period. This application of microdialysis is a useful tool in the study of the physiological role of the mammalian pineal body.

Animals↗
PubMed1989

Long-term profiles of sleep-related hemodynamic changes in the postoperative chronic cat.

The long-term postoperative changes in mean arterial pressure (MAP) and heart rate (HR) during sleep in cats (n = 4) were observed. In the first or second week after surgery, MAP and HR in slow wave sleep (SS) just prior to paradoxical sleep (PS) were higher than those in PS as described in previous reports. In the fourth or fifth week after surgery, the above relationships of MAP and HR between SS and PS were inverted as demonstrated in the present study. The results show that getting true physiological control data is not so simple but a complex task.

Animals↗
PubMedDate not supplied

Spontaneous activity, sleep, and body temperature in rats lacking the CCK-A receptor.

Because of a genetic mutation, the Otsuka-Long-Evans-Tokushima Fatty (OLETF) rat, a model for human non-insulin-dependent diabetes mellitus (NIDDM), shows no expression of the CCK-A receptor gene. We investigated the spontaneous physical activity, sleep, and body temperature in young OLETF rats that had not yet developed diabetes mellitus, and compared these data with age-matched control LETO (non-diabetic strain, Long-Evans-Tokushima-Otsuka) rats. The amount of large movements during the dark phase for the OLETF rats was significantly less than that of control rats. Thus, the amounts of total daily large movement and the ratio of dark-to-light phase movement in the OLETF rats were less than those of control rats, although the amount of small movement was similar for both groups. The diurnal rhythm of body temperature was similar for both groups. In addition, the amount of and circadian rhythm for each vigilance state and slow-wave activity were similar for the two groups. This study demonstrates that the CCK-A receptor might play a role in affecting the level of motor activity, adding hyperphagia, and the circadian rhythm of large movement in these rats prior to the manifestation of NIDDM. In contrast, a CCK-A receptor deficiency does not appear to affect sleep or body temperature in these rats.

Animals↗