|Acceleration of irregular estrous cycle in forced running by midbrain raphe lesions in female rats||山内兄人||脳ラット実験神経科学脳構造画像estrous cyclefemale rats分子神経科学oxidative stressraphe nucleus lesionstressforced running|
書誌： Neuroscience Letters,2011
Neuroscience Letters 495 (2011) 192–195
Hideo Shimizu, Korehito Yamanouchi
It is known that over-exercise or forced running interrupts the regular ovulatory (estrous) cycle in female mammals, including women. The serotonin content of the brain changes under stress conditions. In this experiment, radiofrequency lesions were made in the dorsal (DRL) or median (MRL) raphe nuclei of the midbrain, in which serotonergic neurons are abundant, and changes in the estrous cycle with forced running using an electric-motor running wheel were examined in female rats. Through the tests, the estrous cycle was checked by taking vaginal smears. Female rats with a regular 4-day estrous cycle were forced to run in the wheel for 30 min daily over 15 days. As a result, 27.3% of the control and 30.0% of the sham-operated rats showed an irregular estrous cycle. In contrast, 100% of the DRL and 87.5% of the MRL rats showed an irregular cycle (P < 0.05 vs. control and sham). Statistical analysis revealed that the median onset day of an irregular cycle was in excess of 15 days in both the control and sham groups. In the DRL and MRL groups, the median onset days of the irregular cycle were day 5 and 3, respectively, being shorter than those in control and sham groups (P < 0.01). These results indicate that the dorsal and median raphe nuclei play an important role in preventing the effect of stress conditions in the ovulatory system in female rats.
|Circadian clock gene Period2 regulates a time-of-day– dependent variation in cutaneous anaphylactic reaction||柴田重信||生体リズムマウス実験遺伝学時間生物学遺伝情報Per2anaphylactic reactionIgEcircadian rhythmsmousemast cellclock|
書誌： J ALLERGY CLIN IMMUNOL ,2011
J ALLERGY CLIN IMMUNOL VOLUME 127, NUMBER 4, 1038-1045
Yuki Nakamura,Daisuke Harama, Naomi Shimokawa, PhD, Mutsuko Hara, Ryuyo Suzuki, MD, PhD, Yu Tahara, Kayoko Ishimaru, Ryohei Katoh, MD, PhD, Ko Okumura, MD, PhD, Hideoki Ogawa, MD, PhD, Shigenobu Shibata, PhD, and Atsuhito Nakao, MD, PhD
Background: IgE-mediated immediate-type skin reaction shows a diurnal rhythm, although the precise mechanisms remain uncertain. Period2 (Per2) is a key circadian gene that is essential for endogenous clockworks in mammals. Objective: This study investigated whether Per2 regulates a time-of-day–dependent variation in IgE-mediated immediatetype skin reaction. Methods: The kinetics of a passive cutaneous anaphylactic reaction were compared between wild-type mice and mice with a loss-of-function mutation of Per2 (mPer2 m/m mice). The effects of adrenalectomy, aging, and dexamethasone on the kinetics of a passive cutaneous anaphylactic reaction were also examined. In addition, the extent of IgE-mediated degranulation in bone marrow–derived mast cells (BMMCs) was compared between wild-type and mPer2 m/m mice. Results: A time-of-day–dependent variation in a passive cutaneous anaphylactic reaction observed in wild-type mice was absent in mPer2 m/m mice and in adrenalectomized and aged mice associated with the loss of rhythmic secretion of corticosterone. In addition, mPer2 m/m mice showed decreased sensitivity to the inhibitory effects of dexamethasone on the passive cutaneous anaphylactic reactions. IgE-mediated degranulation in BMMCs was comparable between wild-type and mPer2 m/m mice, but Per2 mutation decreased sensitivity to the inhibitory effects of dexamethasone on IgE-mediated degranulation in BMMCs. Conclusion: A circadian oscillator, Per2, regulates a time-ofday–dependent variation in a passive cutaneous anaphylactic reaction in mice. Per2 may do so by controlling the rhythmic secretion of glucocorticoid from adrenal glands and/or by gating the glucocorticoid responses of mast cells to certain times of the day (possibly when Per2 levels are high in mast cells). (J Allergy Clin Immunol 2011;127:1038-45.)
Key words: Circadian rhythm, clock, Period2, IgE, mast cell, anaphylactic reaction, mouse
|Differences in lower extremity stiffness between endurance-trained athletes and untrained subjects||彼末一之||運動ヒト実験運動生理学行動観察biomechanicstraining adaptationstiffnessathlete|
書誌： Journal of Science and Medicine in Sport ,2010
H. Hobara, K. Kimura, K. Omuro, K. Gomi, T. Muraoka, M. Sakamoto, K. Kanosue (2010). Journal of Science and Medicine in Sport, 13, 106-111.
An understanding of lower extremity stiffness is important for evaluation of sports performance and injury prevention. The aim of this study was to investigate whether stiffness regulation during hopping differed between endurance-trained athletes and untrained subjects. Eight endurance-trained athletes and eight untrained subjects performed two-legged hopping at 2.2 Hz. We determined leg and joint stiffness of hip, knee and ankle from kinetic and kinematics data. The endurance-trained athletes demonstrated signiﬁcantly higher leg stiffness than untrained subjects. Further, the differences in leg stiffness were attributable to differences in ankle and knee joint stiffness. This study demonstrates a possibility that endurance training, like power training, increases leg and joint stiffness.
Keywords: Biomechanics; Training adaptation; Stiffness; Athlete
|Cynical hostility, anger expression style, and acute myocardial infarction in middle-aged japanese men||野村忍||疾患特性ヒト調査臨床心理学身体医学質問紙coronary heart diseasehostilityanger expressionacute myocardial infarction|
書誌： Behavioral Medicine ,2011
Shuhei Izawa, Yumi Eto, Kosuke C. Yamada, Masako Nakano, Haruyo Yamada, Masatoshi Nagayama, Takenori Kikuchi & Shinobu Nomura., (2011), Cynical hostility, anger expression style, and acute myocardial infarction in middle-aged Japanese men, Behavioral Medicine, 37(3), 81-86.
Abstract Studies using American and European populations have demonstrated that high levels of anger/ hostility are predictive of coronary heart disease (CHD) mortality. However, Japanese studies did not show consistent relationship between anger/hostility and CHD. This study examines the association of cynical hostility and anger expression style with acute myocardial infarction (AMI) in middle-aged Japanese men through a case-control study. The patients with acute myocardial infarction (N = 96, mean age = 50.8 years) and the healthy participants in a health check-up program (N = 77, mean age = 50.3 years) were studied. Both groups completed the Cynicism Questionnaire (CQ) and the State-Trait Anger Expression Inventory (STAXI). The patients exhibited higher scores on CQ than the healthy controls. Logistic regression analyses controlling for biological risk factors revealed that the CQ score was associated with increased risk of AMI (OR = 1.11 [95% CI 1.00–1.22]). In addition, the score of Angercontrol, a subscale of STAXI, was associated with decreased risk of AMI (OR = 0.75 [95% CI 0.62–0.92]). These results indicated that higher levels of cynical hostility increased the risk of AMI and that anger-control strategies could have some beneﬁt in reducing the risk of AMI in middle-aged Japanese men.
|Mechanisms of lifespan extension and preventive effects of calorie restriction on tumor development:possible link between central meuroendocrine system and perioheral metabolic adaptation||千葉卓哉||総説遺伝学分子生物学視床下部calorie restrictionDNA damege responseagingoxidative stress糖・脂質代謝glucose metabolismカロリー制限neuroendocrine|
書誌： The Journal of Physical Fitness and Sports Medicine ,2013
Takuya Chiba, Kesu Dong, Shoko Nishizono, Isao Shimokawa. (2013). The Journal of Physical Fitness and Sports MedicineVol. 2, No. 3 p. 259-266. Abstract Restriction of food intake (calorie restriction [CR]) in laboratory animals extends their lifespan and delays the onset of various age-associated diseases, including cancer development. Recent studies revealed that the molecular mechanisms underlying CR-mediated antiaging effects may be regulated by a confined number of signal transduction pathways that are triggered by neuropeptide Y (NPY) neurons in the neuroendocrine system. On the other hand, possible peripheral regulators of the beneficial effects of CR involve a transcriptional regulator complex, the hepatocyte nuclear factor 4α/peroxisome proliferator-activated receptor gamma coactivator 1-α (HNF-4α/PGC-1α) complex. This complex could regulate not only glucose and lipid metabolism, but also DNA damage responses in the liver. Therefore, maintenance of optimal glucose and lipid levels to prevent metabolic syndrome, and activation of the DNA damage response for suppression of tumor development, may depend on the HNF-4α/PGC-1α complex. Hence, small molecules modulating the activity of this complex could be an important target for development of CR mimetics (CRM), which mimic the beneficial effects of CR without actual food restriction. Keywords : aging, calorie restriction, glucose metabolism, neuroendocrine, oxidative stress