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Sadamasa ISHIKAWA Kou HIRAGA Yuuki HIRADATE Kentaro TANEMURA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):725-728
Acetamiprid (ACE) and imidacroprid (IMI) are known neonicotinoid insecticides with strong
affinities for the insect-selective nicotinic acetylcholine receptor. These provide insect
control by hyperstimulating insect nerves and are used for agricultural pest management.
However, it has also been reported that ACE and IMI affect mammalian reproductive
function. We determined the effects of ACE and IMI on the in vitro
maturation of porcine oocytes. Significant decreases in nuclear maturation rates were
observed in the ACE or IMI-exposed groups. Also, in matured oocytes from the ACE or
IMI-exposed groups, irregular chromosomes were observed. Our results suggest that ACE and
IMI exposure was detrimental to porcine oocytes and the extent of the effects depends on
the concentration of exposure. 相似文献
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Hirokazu TSUBONE Masakazu HANAFUSA Maiko ENDO Noboru MANABE Atsushi HIRAGA Hajime OHMURA Hiroko AIDA 《Journal of Equine Science》2013,24(1):1-8
The present study aimed to clarify changes of oxidative stress and antioxidative
functions in treadmill-exercised Thoroughbred horses (n=5, 3 to 7 years old), using
recently developed techniques for measurement of serum d-ROMs for oxidative stress, and
BAP for antioxidative markers. Also, the effect of nasogastric administration of
hydrogen-rich water (HW) or placebo water preceding the treadmill exercise on these
parameters was examined. Each horse was subjected to a maximum level of treadmill exercise
in which the horses were exhausted at an average speed of 13.2 ± 0.84 m/sec. Blood samples
were taken 4 times, immediately before the intake of HW or placebo water at 30 min
preceding the treadmill exercise, immediately before the exercise (pre-exercise),
immediately after the exercise (post-exercise) and at 30 min following the exercise. In
all horses, both d-ROMs and BAP values significantly increased at post-exercise. The
increase in d-ROMs tended to be lower in the HW trial, as compared to the placebo trial at
pre-exercise. The increase in BAP was considerable at approximately 150% of the
pre-exercise values in both the HW and placebo treatment trials. The BAP/d-ROMs ratio was
significantly elevated at post-exercise in both treatment trials, while a significant
elevation was also observed at pre-exercise in the HW trial. BAP, d-ROM, and the BAP/d-ROM
ratio tended to decline at 30 min after the exercise, except BAP and BAP/d-ROMs in the
placebo trial. These results demonstrate that the marked elevation of oxidative stress and
anitioxidative functions occurred simultaneously in the intensively exercised horses, and
suggest a possibility that HW has some antioxidative efficacy. 相似文献
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Kou HIRAGA Yumi HOSHINO Kentaro TANEMURA Eimei SATO 《The Journal of reproduction and development》2013,59(4):405-408
Localization patterns of lipid droplets in the cytoplasm of porcine oocytes were
evaluated as a novel marker for in vitro maturation (IVM) of oocytes with
high developmental competence. Porcine oocytes were cultured in TCM-199, which is a
complete synthetic medium, for 44 h at 38.5 C. Localization patterns were divided into 2
classes: lipid droplets localized uniformly in the whole cytoplasm (class I) and those
that were centrally located (class II). After IVM in TCM-199, 60% of matured oocytes
exhibited the class II pattern. To investigate the relation between the distribution of
lipid droplets and the developmental rate of the oocyte, the developmental rates of class
I and class II oocytes were compared after in vitro fertilization (IVF).
Class II oocytes showed a significantly higher rate of blastocyst development than class I
oocytes. These results suggest that porcine oocytes with high developmental competence can
be selected based on the localization patterns of lipid droplets. 相似文献
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Yoshio MINAMI Seiko YAMANO Minako KAWAI Atsushi HIRAGA Hirofumi MIYATA 《Journal of Equine Science》2009,20(3):33-40
To find a new parameter indicating muscle fitness in Thoroughbred horses, we examined
time-dependent recovery of glycogen content and sarcoplasmic reticulum (SR)
Ca2+-ATPase activity of skeletal muscle after intensive treadmill running.
Two repeated 50-sec running sessions (13 m/sec) were performed on a flat treadmill
(approximately 90%VO2max). Muscle samples of the middle gluteal muscle were
taken before exercise (pre) and 1 min, 20 min, 60 min, and 24 hr after exercise. Muscle
fiber type composition was determined in the pre muscle samples by immunohistochemical
staining with monoclonal antibody to myosin heavy chain. SR Ca2+-ATPase
activity of the muscle and glycogen content of each muscle fiber type were determined with
biochemical analysis and quantitative histochemical staining, respectively. As compared to
the pre value, the glycogen content of each muscle fiber type was reduced by 15–27% at 1
min, 20 min, and 60 min after the exercise and recovered to the pre value at 24 hr after
exercise test. These results indicate that 24 hr is enough time to recover glycogen
content after short-term intensive exercise. The mean value of the SR
Ca2+-ATPase activity showed a slight decrease (not significant) immediately
after exercise, and complete recovery at 60 min after exercise. There were no significant
relationship between the changes in glycogen content of each muscle fiber type and SR
Ca2+-ATPase. Although further studies are needed, SR Ca2+-ATPase
is not a useful parameter to detect muscle fitness, at least in Thoroughbred horses. 相似文献
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Seiko YAMANO Minako KAWAI Yoshio MINAMI Atsushi HIRAGA Hirofumi MIYATA 《Journal of Equine Science》2010,21(4):59-65
We evaluated differences in muscle fiber recruitment patterns between continuous and
interval training to develop an optimal training program for Thoroughbred horses. Five
well trained female thoroughbred horses (3–4 years old) were used. The horses performed
two different exercises on a 10% inclined treadmill: 90%VO2 max for 4 min
(continuous) and 90% VO2 max for 2 min × 2 times with 10-min interval
(interval). Muscle samples were obtained from the middle gluteal muscle before and
immediately after the exercises. Four muscle fiber types (type I, IIA, IIA/X, and IIX)
were immunohistochemically identified, and the optical density of periodic acid Schiff
staining (OD-PAS) in each fiber type and glycogen content of the muscle sample were
determined by quantitative histochemical and biochemical procedures, respectively. No
significant differences were found in the OD-PASs and glycogen contents between the
continuous and interval exercises, but the decreases in OD-PAS of fast-twitch muscle
fibers were obvious after interval as compared to continuous exercise. Interval exercise
may be a more effective training stimulus for the glycolytic capacity of fast-twitch
muscle fiber. The data about muscle fiber recruitment can provide significant insights
into the optimal training program not only for thoroughbred horses, but also for human
athletes. 相似文献
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ISAO TAKAHASHI KENSAKU AZUMA SHINJI FUJITA IZUMI KINOSHITA HIROYUKI HIRAGA 《Fisheries Science》2003,69(3):438-444
ABSTRACT: Larval and juvenile ayu from seven year-groups (1986, 1987, 1992, 1995, 1996, 1999 and 2000) were collected in the Shimanto Estuary and adjacent coastal waters. The present study focuses on the variation among year-groups in the hatching period estimated by age determination using the otolith. The hatching period of the dominant cohorts in the 1986, 1987 and 1992 year-groups occurred from late October to mid-November. A delay of the hatching period of the dominant cohort was observed from the 1995 year-group, which occurred in late November to early December, and the dominant periods in the 1996, 1999 and 2000 year-groups were observed from early to late December. It appears that the delay of the hatching period of dominant cohorts was not due to a delay of spawning, but a high mortality of early hatched larvae. The water temperature in autumn in the coastal waters adjacent to the Shimanto River has tended to rise over the past 20 years and this trend was especially notable in the late 1990s. The delay in the hatching period of the dominant cohort observed from the 1995 year-group was likely to be related to the rise in seawater temperatures in autumn. 相似文献
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Yoshio MINAMI Minako KAWAI Taiko C. MIGITA Atsushi HIRAGA Hirofumi MIYATA 《Journal of Equine Science》2011,22(2):21-28
Although high oxygen consumption in skeletal muscle may result in severe oxidative
stress, there are no direct studies that have documented free radical production in horse
muscles after intensive exercise. To find a new parameter indicating the muscle adaptation
state for the training of Thoroughbred horses, we examined free radical formation in the
muscle by using electron paramagnetic resonance (EPR). Ten male Thoroughbred horses
received conventional training for 18 weeks. Before and after the training period, all
horses performed an exhaustive incremental load exercise on a 6% incline treadmill. Muscle
samples of the middle gluteal muscle were taken pre-exercise and 1 min, 1 hr, and 1 day
after exercise. Muscle fiber type composition was also determined in the pre-exercise
samples by immunohistochemical staining with monoclonal antibody to myosin heavy chain. We
measured the free radical in the muscle homogenate using EPR at room temperature, and the
amount was expressed as relative EPR signal intensity. There was a significant increase in
Type IIA muscle fiber composition and a decrease in Type IIX fiber composition after the
training period. Before the training period, the mean value of the relative EPR signal
intensity showed a significant increase over the pre-exercise value at 1 min after the
exercise and an incomplete recovery at 24 hr after the exercise. While no significant
changes were found in the relative EPR signal intensity after the training period. There
was a significant relationship between percentages of Type IIA fiber and change rates in
EPR signal intensity at 1 min after exercise. The measurement of free radicals may be
useful for determining the muscle adaptation state in the training of Thoroughbred
horses. 相似文献