Yasuaki Kumamoto

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In vivo microdialysis was employed to measure the extracellular concentrations of dopamine (DA) in the medial preoptic area (MPOA) of rats during male sexual activity to look for a correlation with sexual activity. During copulation, the concentration of DA in the MPOA was significantly increased. A significant difference was detected in changes of DA(More)
The effects of long-term psychological stress on sexual behavior and brain catecholamines were investigated in rats. Stress was applied using the communication box developed by Ogawa and Kuwabara (1996), and a psychological stress group (n = 12), a physical stress group (n = 5), and a control group (n = 5) were established. Stress was applied for 1 hour(More)
Magnetoencephalography (MEG) is a procedure that analyzes the magnetic responses of neurons. An MEG system with a 37-channel superconductivity quantum interference device (SQUID) was used to record magnetic signals from the human brain in response to tactile stimulations of the face and oral cavity. Six normal individuals were studied as well as three(More)
Raman spectroscopy, which identifies intrinsic molecular constituents, has a potential for determining myocardial viability under label-free conditions. However, its suitability for evaluating myocardial ischaemia is undetermined. Focusing on cytochromes, i.e., representative molecules reflecting mitochondrial activity, we tested whether Raman spectroscopy(More)
We employed deep UV (DUV) Raman spectroscopy for characterization of molecular photodamage in cells. 244 nm light excitation Raman spectra were measured for HeLa cells exposed to the excitation light for different durations. In the spectra obtained with the shortest exposure duration (0.25 sec at 16 µW/µm(2) irradiation), characteristic resonant Raman bands(More)
It is reported that some elderly males exhibit both hypospermatogenesis and intratesticular arterial changes. These arterial changes are thought to contribute to spermatogenic damage. In this study the process of the damage to spermatogenesis induced by such changes was evaluated using stroke-prone spontaneously hypertensive rats (SHRSP). SHRSP showed a(More)
The relationship between sexual behavior and long-term stress in male Wistar rats was investigated. Rats were divided into two groups, one of which exposed to electrical foot shock for 1 hour a day for 10 weeks to create physical stress. The other group was exposed to the rats receiving shock to create psychological stress. Rats in both groups were placed(More)
We have reported that sexual behavior of male rats is impaired by long-term psychological stress. We measured dopamine (DA) and its metabolites (3,4-dihydroxyphenylacetic acid, DOPAC, and homovanillic acid, HVA) in the brain of rats which were exposed to the long-term stress. Our experiment was focused on the medial preoptic area (MPOA), which is perhaps(More)
Nocturnal LH pulse was analyzed in 4 prepubertal, 3 early pubertal and 2 midpubertal boys by measuring serum LH concentrations. Blood samples were taken every 30 minutes while awake, and every 20 minutes after subjects had gone to sleep. Serum LH was measured by using immunofluorometric assay (IFMA) with a lower detection limit of 0.02mIU/ml. Pulsatile LH(More)
After an exposure of 24 h to synthetic LHRH (100 ng/ml) in vitro, the anterior pituitaries of 4-day-old rats show a notable loss of immunoreactive material in most LH cells in males, but not in females. When radioimmunoassayed without incubation, the pituitary LH content of 4-day-old female rats is 2.8 times higher than that of males of the same age. LHRH(More)