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排序方式: 共有267条查询结果,搜索用时 15 毫秒
21.
22.
Sakatani M Yamanaka K Kobayashi S Takahashi M 《The Journal of reproduction and development》2008,54(6):496-501
Heat shock is known to increase the mortality of early stage embryos, but the exact mechanism is unclear. In the present study, we investigated the possibility that the increased mortality is caused by heat shock-generated reactive oxygen species (ROS). The level of ROS was controlled by using beta-mercaptoethanol (beta-ME), a scavenger of ROS. In vitro-produced 8-cell stage embryos were cultured at 38.5 C or heat-shocked by exposure to 41 C for 6 h with 0, 10 and 50 microM beta-ME. Intracellular ROS levels were measured by a fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate (DCHFDA), and intracellular reduced form of glutathione (GSH) contents were estimated by another fluorescent dye, 4-chloromethyl-6,8-difluoro-7-hydroxycoumarin. Total glutathione content was estimated by the glutathione recycling assay. On day 8 after insemination, heat shock decreased the percentage of embryos that developed to the blastocyst stage and increased intracellular ROS levels, but there was no significant effect on the GSH and total glutathione contents. In contrast, beta-ME significantly decreased ROS levels in heat-shocked embryos and increased the GSH and total glutathione concentrations. Ten microM beta-ME significantly improved the viability of heat-shocked embryos. beta-ME caused no detrimental effects when it was added at normal culture temperature (38.5 C). These results indicate that ROS is the primary cause of increased embryonic mortality in heat-shocked early stage embryos. 相似文献
23.
Fukushima R Ichikawa K Hirabayashi M Yamagami T Koyama H Hirose H Uchino T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(8):993-995
The dog of this case was a 10-year-old Shih Tzu with refractory vomiting, diarrhea and anorexia. Endoscopy revealed an unclear at gastric angle, a stenosis at pyloric antrum and congestion in duodenal mucosa. Since abnormal shadows of irregular echo-levels were disclosed by pancreas ultrasonography, serum gastrin level was determined with a suspect of gastrinoma. And an increase of serum gastrin was demonstrated. In addition, postmortem histological examination revealed that the pancreatic cells were positive for gastrin. Based on these findings, the dog was diagnosed as pancreatic gastrinoma. 相似文献
24.
The effect of intermittent administration of sustained release isosorbide dinitrate (sr-ISDN) in rats with volume overload heart 总被引:1,自引:0,他引:1
Shimamura S Ohsawa T Kobayashi M Hirao H Shimizu M Tanaka R Yamane Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(1):49-54
Recently, it has been reported that intermittent administration of nitrate, with a nitrate-free interval of 10 to 12 hr eliminated expression of tolerance, and maintained its hypotensive effect. In the present study, we evaluated whether nitrate tolerance developed or not with an intermittent administration of sr-ISDN (5 mg/kg/ once a day) in Wistar rats. The effect of this administration protocol for sr-ISDN on the volume overload heart model, aortovenous fistula, was also examined. Furthermore, blood pressure was monitored by radio telemetry during sr-ISDN (5 mg/kg/once a day) administration. Nitrate tolerance did not develop, and eccentric hypertrophy due to volume overload was moderated by sr-ISDN administration. Sr-ISDN administration maintained blood pressure lower level than the placebo group. In conclusion, prolonged intermittent administration of sr-ISDN maintained its hypotensive effect during the entire experiment period, without developing tolerance, and moderated efferent hypertrophy with attenuated volume overload. 相似文献
25.
Shimizu M Tanaka R Uchida M Orito K Shimamura S Yamane Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(3):227-233
It has been reported that cardiac chymase has an effect on cardiac fibrosis through the Angiotensin (Ang) II formation and an Ang II-independent mechanism. In the present study, Ang II type 1 (AT1) receptor blocker (candesartan cilexetil) was administered to dilated cardiomyopathic (DCM; Bio TO2) hamsters for 4 weeks to study the effect of AT1 receptor blocker on cardiac chymase-like activity and cardiac fibrosis. Echocardiography, histological examination, and assessment of cardiac angiotensin-converting enzyme (ACE)/chymase-like activities were conducted. Hamsters showed cardiac dysfunction due to increased left ventricular dimensions and decreased ventricular wall thickness, significant increase in cardiac chymase-like activity, and fibrosis. This result indicates that the cardiac chymase-like activity is responsible for cardiac fibrosis. When candesartan cilexetil was administered to Bio TO2 hamsters, cardiac chymase-like activity increased significantly, whereas cardiac fibrosis decreased significantly. Cardiac ACE and chymase-like activities were unchanged in non-DCM hamsters with candesartan cilexetil. This suggests that the cardiac Ang II formation mechanism was stimulated by suppressing the effect of cardiac Ang II, and cardiac chymase-like activity could be increased. Moreover, this mechanism may be more highly activated if cardiac Ang II is activated in the heart. In conclusion, we demonstrated that AT1 receptor blocker reduced cardiac fibrosis, although cardiac chymase-like activity increased. Because the Ang II-forming pathway and the effect of chymase in hamsters is similar to that in dogs, the results of the present study may supplement the available information for dogs. 相似文献
26.
Mortality and morbidity of neonates continue to be major problems in humans and animals, and immunoblogulin A (IgA) provides protection against microbial antigens at mucosal surfaces. The present study was conducted to clarify the effects of coumestrol administration to maternal mice during pregnancy and lactation on IgA antibody‐secreting cells (ASC) in mammary glands in lactating mice. From 6.5 to 16.5 days post coitus and 1 to 13 days post partum (dpp), maternal mice were administered coumestrol at 200 μg/kg body weight/day. Coumestrol administration increased the number of IgA ASC and the messenger RNA expression of IgA C‐region and vascular cell adhesion molecule‐1 in mammary glands of maternal mice at 14 dpp, but coumestrol administration had no effect on the number of IgA ASC in the ileum. Coumestrol administration increased serum IgA concentration in maternal mice at 14 dpp, but IgA concentrations in serum, stomach contents, intestine and feces of neonatal mice were not affected by treatment. These results imply that coumestrol administration to maternal mice during pregnancy and lactation is effective in increasing the numbers of IgA ASC in mammary glands during lactation owing to the activated messenger RNA expressions of IgA C‐region and vascular cell adhesion molecule‐1 in mammary gland. 相似文献
27.
Yoshie MANABE Makoto TOCHIGI Akiyoshi MORIWAKI Sakae TAKEUCHI Sumio TAKAHASHI 《The Journal of reproduction and development》2013,59(4):398-404
Reproductive functions decline with the onset of diabetes in female mice. Diabetic mice
have smaller uteri with an underdeveloped endometrium, suggesting diminished
estrogen-induced growth. We aimed to clarify the changes in the estrous cycle and in
insulin-like growth factor 1 (IGF1) expression in the uteri of streptozotocin
(STZ)-treated diabetic mice, because IGF1 is one of the main growth factors involved in
estrogen-induced uterine growth. ICR female mice were intraperitoneally administered STZ
(10 mg/100 g BW), and blood glucose levels were determined. Mice with blood glucose levels
> 200 mg/dl were classified as diabetic mice. The onset of diabetes was associated with
acyclic estrous cycles. Diabetes was also induced with STZ in ovariectomized mice. Uterine
Igf1 mRNA levels were reduced in ovariectomized STZ-treated diabetic
mice. Estrogen is known to stimulate Igf1 mRNA expression in the uterus,
but estrogen action was abolished in the uteri of STZ-treated diabetic mice. mRNA
expressions of estrogen receptor α (ERα) and steroid hormone receptor coactivators
(SRC-1/Ncoa1, SRC-2/Ncoa2,
SRC-3/Ncoa3 and CBP/p300/Crebbp) were reduced in the
uteri of ovariectomized STZ-treated diabetic mice. The present study demonstrates that
diabetes induces a decline in female reproductive functions in mice. Igf1
expression in ovariectomized diabetic female mice was decreased, and decreased
responsiveness to estrogen in the uteri of diabetic mice is probably associated with a
reduction in ERα and steroid receptor coactivator mRNA expression. 相似文献
28.
Camilla Dooleweerdt Rasmussen Maria Mathilde Haugaard Morten Roenn Petersen Jesper M?ller Nielsen Hanne Gervi Pedersen Anders Miki Bojesen 《Veterinary research》2013,44(1):26
Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n = 18) or without (n = 11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare. 相似文献
29.
Sarengaowa Aierqing Akiko Nakagawa Miki Okita Takashi Bungo 《Animal Science Journal》2019,90(10):1407-1413
Play behavior in young animals has been used to evaluate the condition (health) of livestock. We investigated age, sex, and genetic differences of Japanese Black calves in relation to frequency of play behaviors (galloping, leaping, turning, bucking, head butting objects, and head shaking) and examined how these relationships might affect growth during the suckling stage. Locomotor play behaviors (galloping, leaping, turning, and bucking) and head butting objects gradually declined with the age for both sexes. The frequency of head butting was significantly higher in males than females. We found that significant interaction effects (age × MAOA polymorphism) in play behaviors (except head shaking) and the frequencies of locomotor play in calves without the wild‐type allele were significantly higher than those in younger calves (2 and 6 weeks of age). Weight gain was significantly correlated with the frequency of locomotor play in females, but not in males. This study suggests that play in Japanese Black calves gradually declines as they mature and that play may be controlled by variations in the MAOA gene. In addition, the frequency of locomotor play may be an indicator of health in female calves. 相似文献
30.
Hisashi Nishiwaki Yoshiaki Nakagawa David Y Takeda Atsushi Okazawa Miki Akamatsu Hisashi Miyagawa Tamio Ueno Keiichiro Nishimura 《Pest management science》2000,56(10):875-881
Variously substituted benzyl derivatives of chloronicotinyl insecticides were synthesized with a wide range of substituents including halogens, NO2, CN, CF3 and small alkyl and alkoxy groups at the ortho, meta and para positions, as well as multiple‐substituted benzyl analogues. Their binding activity to the α‐bungarotoxin binding site in housefly (Musca domestica) head membrane preparations was measured. Among the compounds tested, the activity of the meta‐CN derivative was the highest, being 20–100 times higher than those of imidacloprid, acetamiprid and nitenpyram. The synergized insecticidal activity against houseflies was also measured for selected compounds with the metabolic inhibitor, NIA16388 (propargyl propyl phenylphosphonate). For the nitromethylene analogues, including both benzyl and pyridylmethyl analogues, higher binding activity usually resulted in higher insecticidal activity. © 2000 Society of Chemical Industry 相似文献