著者

Takao Sugiura Naoko Ito Katsumasa Goto Hisashi Naito Toshitada Yoshioka Scott K. Powers

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

The Journal of Physiological Sciences (ISSN:18806546)

巻号頁・発行日

vol.56, no.6, pp.393-399, 2006 (Released:2006-12-28)

参考文献数

43

被引用文献数

34 37

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We tested the hypothesis that estrogen administration would retard immobilization-induced muscle atrophy in adult male rats. The rats were injected for 24 days with either estrogen (40 μg/kg−1, β-estradiol 3-benzoate in olive oil vehicle), or vehicle alone. At day 14 of estrogen treatment, the hindlimb muscles of one leg were immobilized in plantar flexion position by the use of a plaster cast. Following 10 days of immobilzation, the atrophic and the contralateral soleus muscles were both removed and analyzed to determine the level of muscle atrophy along with the measurement of the protein levels of Cu-Zn-superoxide dismutase (Cu-Zn-SOD), heat shock protein 72 (HSP72), and selected proteases. Compared to placebo animals, estrogen treatment significantly reduced (–35%) muscle atrophy. Further, estrogen significantly abridged the expression of the calcium-activated protease, calpain, in the atrophied hindlimb muscle. In contrast, estrogen treatment did not alter the protein levels of HSP72 in the immobilized soleus muscle. These results support the postulate that estrogen attenuates the rate of disuse muscle atrophy, partly because of reductions in immobilization-induced calcium-activated protease levels.

著者

Akihiro KUROSHIMA Masashi KURAHASHI Katsuhiko DOI Tomie OHNO Ikuko FUJITA

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

The Japanese Journal of Physiology (ISSN:0021521X)

巻号頁・発行日

vol.24, no.3, pp.277-292, 1974 (Released:2011-06-07)

参考文献数

23

被引用文献数

9 14

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Effects of cold adaptation and high-fat diet on the metabolic responses as well as cold resistance to acute cold exposure were investigated in rats with emphasis on elucidating the mechanism underlying the favorable effect of high-fat diet in a cold environment previously reported.An increment in body weight was greater in rats on a high-fat diet and smaller in cold-adapted rats than in control rats. However, food intake was significantly greater in cold-adapted rats. Daily urine volume and urinary nitrogen excretion increased in cold-adapted rats, but did not change in rats on a high-fat diet. The high-fat diet caused higher bloodfree fatty acid (FFA) and ketone body concentrations, and lower urinary excretion of ketone bodies. Urinary vanilmandelic acid excretion was significantly elevated in cold-adapted rats, while it was lower in rats fed a high-fat diet as compared with that in control rats. This result suggests an increased sympathetic activity in cold-adapted rats and a rather suppressed activity in rats on a high-fat diet.The fall in the colonic temperature due to cold exposure for the period of time up to four hours was significantly less in cold-adapted rats, but did not differ in animals fed a high-fat diet from that in control rats. This result signifies that there is no significant difference in cold resistance between control rats and rats on a high-fat diet. Blood FFA level as well as blood ketone body level was significantly raised in all experimental groups in response to cold exposure. It was observed, however, that an increment in blood FFA concentration was less in cold-adapted rats. The degree of increase in blood FFA became greater with length of exposure to the cold. Blood glucose concentration was significantly elevated in cold-adapted rats after an eighty minutes exposure to the cold, but did not vary in control rats and rats on a high-fat diet. Four hours after the cold exposure the blood glucose level was significantly decreased in all groups as compared with that at 25°C.There was a significant correlation between the blood FFA and ketone body concentrations on the whole data before and after cold exposure in all groups. Regression coefficient between blood compositions was significantly greater in rats fed a high-fat diet than in control and coldadapted rats. It was also shown that there was an inverse correlation between the blood glucose and FFA levels after cold exposure. Furthermore, lessened falling of colonic temperature due to cold exposure was significantly associated with less variations in the blood FFA and glucose levels concomitantly determined in control and cold-adapted rats and this tendency was strongly documented in cold-adapted rats.The present results indicate that the prolonged cold exposure increases the cold resistance to acute cold exposure, while the high-fat diet feeding may not be necessarily favorable to the cold resistance, although a high-fat diet causes certain metabolic changes, suggesting a favorable effect to some extent.

著者

Lee Yukyung Choi Gaeun Jeon Hyongjun Kim Dongsoo Ryu Sun Koo Sungtae Ha Ki-Tae Kim Seungtae

出版者

Physiological Society of Japan

雑誌

The journal of physiological sciences (ISSN:18806546)

巻号頁・発行日

vol.68, no.4, pp.455-462, 2018-07

著者

武田 紗路 藤井 陽平 ウェチュレック ニーナ オッファマン ステファン 坪川 宏

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

日本生理学会大会発表要旨集

巻号頁・発行日

pp.153, 2007 (Released:2007-07-10)

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Although electrical properties of the dendrites are going to be clarifying, little is known about the physiological roles of dendritic spike. Since spike backpropagation could depolarize the inhibitory postsynapses, it may induce transient suppression of GABAergic inhibition (DSI) through an activation of presynaptic cannabinoid receptor (CBR). In this study, we examined whether action potentials induce DSI in mouse hippocampal neurons. Whole-cell voltage-clamp or current-clamp recording was made from the soma and/or the dendrite of CA1 neurons, and changes in amplitude of IPSCs (or IPSPs) after antidromic action potentials were analyzed. We found that train of antidromic spikes could induce transient suppression of GABAergic IPSCs (or IPSPs), which have CBR-dependent and TEA-sensitive components. However, depolarization by current injection to the dendrite failed to induce CBR-dependent suppression, indicating that somatic depolarization was required. In the presence of TEA, application of phorbol ester, which facilitates spike backpropagation, enhanced DSI, and application of somatostatine, which inhibits backpropagation, reduced DSI. These results suggest that in physiological condition antidromic invasion of Na+ spikes into dendrites induce DSI in hippocampal GABAergic synapses. Supported by a grant from Japanese Ministry of Education, Science, Sports and Culture (to H.T). [J Physiol Sci. 2007;57 Suppl:S153]

著者

Matsukawa Kanji Endo Kana Ishii Kei Ito Momoka Liang Nan

出版者

Physiological Society of Japan

雑誌

The journal of physiological sciences (ISSN:18806546)

巻号頁・発行日

vol.68, no.2, pp.175-190, 2018-03

著者

松井 等 松井 等 高井 章 柏柳 誠

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

日本生理学会大会発表要旨集

巻号頁・発行日

pp.S123, 2005 (Released:2005-04-16)

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In olfactory receptor cells, it is well established that cAMP acts as a main second messenger during odor responses. Biochemical experiments, however, showed failure of accumulation of cAMP in olfactory cilia by odorants of 40% examined (Sklar et al., 1996). We have shown that application of water soluble odorants and volatile odorants induced inward currents in olfactory cells of the Xenopus water nose but dialysis with cAMP did not (Iida and Kashiwayanagi, 1999). Breer and Boekhoff showed that odorants, which did not induce cAMP accumulation in olfactory cilia, induced IP3 accumulation (1990). Dialysis of olfactory cells in Xenopus water nose with IP3 induced inward currents. In addition, the turtle olfactory cells responded to dialysis with cyclic ADP-ribose (cADPR) with an inward current (Sekimoto and Kashiwayanagi, 2003). The magnitudes of the inward current responses to cAMP-increasing odorants were greatly reduced by prior dialyses of a high concentration of cADPR or 8-Br-cADPR, an antagonist. It is possible that IP3 and cADPR play as second messengers during the olfactory transduction. At present, channel molecules which are activated by these second messenger candidates have not been identified in olfactory cells. Transient receptor potential (TRP) channels, which are expressed in many tissues and cell types in vertebrates, are activated by various stimulations. In the present study, we explore roles of TRP channels in the olfactory system by RT-PCR and immunohistochemical techniques. [Jpn J Physiol 55 Suppl:S123 (2005)]

著者

Shun Sato Chengzhu Yin Akira Teramoto Yasuo Sakuma Masakatsu Kato

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

The Journal of Physiological Sciences (ISSN:18806546)

巻号頁・発行日

vol.58, no.5, pp.317-322, 2008 (Released:2008-10-29)

参考文献数

47

被引用文献数

7 16

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Gonadotropin-releasing hormone (GnRH) neurons represent the final output neurons in the central control of reproduction. γ-Amino butyric acid (GABA), one of the major regulators of GnRH neurons, depolarizes GnRH neurons isolated from adult rats via GABAA receptors. The presence of GABAA receptors in GnRH neurons has also been demonstrated morphologically. Furthermore, the pineal hormone melatonin is involved in the regulation of reproductive function, including the timing of the luteinizing hormone surge. The suprachiasmatic nucleus and the GABAergic system in the medial preoptic area are considered as possible sites of the action of melatonin. Until now, however, a direct action of melatonin on GnRH neurons has not been reported. Therefore we examined the effect of melatonin on GABAA receptor currents in GnRH neurons isolated from GnRH-EGFP transgenic rats by means of perforated patch-clamp experiments. The GABAA receptor currents were modulated by melatonin in a sex-specific manner. In GnRH neurons from adult males, melatonin augmented these currents in 67% of the neurons examined, but attenuated the currents in only 19% of them. These modulations were blocked by the melatonin receptor antagonist luzindole, suggesting an involvement of melatonin receptors. The modulation by melatonin was not observed in GnRH neurons isolated from infantile rats. These findings indicate that GABA affects the excitability of GnRH neurons in adult rats through GABAA receptors, and that melatonin modifies this excitability via melatonin receptors in a sex-specific manner.

著者

Kazushige Goto Kazumasa Takahashi Masato Yamamoto Kaoru Takamatsu

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

The Journal of Physiological Sciences (ISSN:18806546)

巻号頁・発行日

vol.58, no.1, pp.7-14, 2008 (Released:2008-02-23)

参考文献数

33

被引用文献数

22 33

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This study examined acute hormone and recovery responses to resistance exercise with slow movements. Six men performed three types of exercise regimens (five sets of knee extension exercise): (1) high-intensity resistance exercise with normal movement (HN; 1 s for lifting action, 1 s for lowering action), (2) low-intensity resistance exercise with slow movement (LS; 3 s for lifting action, 3 s for lowering action), and (3) low-intensity resistance exercise with normal movement (LN; 1 s for lifting action, 1 s for lowering action). The intensity in the first set was set at approximately 80% of 1RM for HN and 40% of 1RM for LS and LN. In the HN and LS, the subjects performed each exercise set until exhaustion. In the LN, both intensity and number of repetitions were matched with those for LS. The total work volume in the HN showed approximately double the value of LS and LN (P < 0.05). Electromyography (EMG) data indicated that LS showed sustained EMG signals throughout the exercise. During the exercise, the HN and LS showed lower muscle oxygenation levels. After the exercise, LS caused significantly greater norepinephrine and free testosterone responses (delta value) than in the HN and LN (P < 0.05). However, no significant difference was observed in the recovery of maximal isometric strength, isokinetic strength, and jump performance between the HN and LS. These results indicate that slow movements during the resistance exercise are important for the enhancement of hormonal responses, especially catecholamine and free testosterone, but they do not affect muscle strength recovery.

著者

Gerlinger-Romero Frederico Guimaraes-Ferreira Lucas Yonamine Caio Yogi Salgueiro Rafael Barrera Nunes Maria Tereza

出版者

Physiological Society of Japan

雑誌

The journal of physiological sciences (ISSN:18806546)

巻号頁・発行日

vol.68, no.2, pp.165-174, 2018-03

著者

Kimura Shingo Kawasaki Satoshi Takashima Koichiro SASAKI Kazuhiko

出版者

Physiological Society of Japan

雑誌

The Japanese journal of physiology (ISSN:0021521X)

巻号頁・発行日

vol.51, no.4, pp.511-521, 2001-08

被引用文献数

4