Effects of 3-methyl-4-nitrophenol in diesel exhaust particles on the regulation of reproductive function in immature female Japanese quail (Coturnix japonica)     

Li C  Takahashi S  Taneda S  Furuta C  Watanabe G  Suzuki AK  Taya K 《The Journal of reproduction and development》2007,53(3):673-678

In a previous study, we found that 3-methyl-4-nitrophenol (PNMC), a component of diesel exhaust particles and also a degradation product of the insecticide fenitrothion, exhibits reproductive toxicity in the adult male Japanese quail. The present study investigated the toxicity of PNMC in the female Japanese quail and its ability to influence reproduction in immature females. The quail (21-day-old) were injected intramuscularly (im) with PNMC at doses 0.1, 1 or 10 mg/kg body weight daily for 3 days. There was no significant difference in body growth between the PNMC-administered and control birds. However, the weights of the oviducts were significantly lower in the PNMC-treated birds at all doses. Furthermore, the plasma concentrations of luteinizing hormone (LH) and estradiol-17 beta were significantly decreased with 1 and 10 mg/kg of PNMC. These findings suggest that PNMC might influence the hypothalamo-pituitary-gonadal axis with decreasing in secretion of GnRH, LH and ovarian steroid hormones and subsequently disturb growth of the reproductive organs of immature female quail. This study indicates that PNMC induces reproductive toxicity at the central level and disrupts reproductive function in the immature female quail.  相似文献   

Apoptosis in the porcine uterine endometrium during the estrous cycle, early pregnancy and post partum     

Okano A  Ogawa H  Takahashi H  Geshi M 《The Journal of reproduction and development》2007,53(4):923-930

The mammalian uterus changes dramatically during the estrous cycle, pregnancy, and involution post partum. Dynamic changes in the uterine endometrium are a type of homeostasis and proceed with proliferation and exclusion of cells. Homeostasis of the uterus is closely related to apoptosis involving various hormones and cytokines. The objective of the present study was to determine the morphological features and occurrence of apoptosis in the porcine endometrium during the estrous cycle, early pregnancy, and post partum. Cyclic changes in the morphology of the surface epithelium were observed during the estrous cycle. The heights of surface epithelia were significantly high on day 4 of the estrous cycle and the early pregnancy. The heights of the surface epithelium remained low from days 1 to 31 post partum. We then used terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end-labeling (TUNEL) of the 3'-terminal of fragmented DNA, which is effective for detection of apoptosis in various tissues. We found that apoptosis in the porcine endometrium contributed to homeostasis of the endometrium during the estrous cycle through control of cell proliferation and exclusion. Conversely, apoptosis on days 4 and 8 of gestation before the implantation window depended on the plasma estrogen and progesterone levels; however, suppressive homeostasis of apoptosis occurred at the time of implantation on days 15, 18 and 21 of gestation. Our study is the first to demonstrate apoptotic cell death in the porcine endometrium directly by TUNEL method. The results strongly suggest that uterine homeostasis is mainly controlled by apoptosis during the estrous cycle and early pregnancy.  相似文献   

Gene silencing of cyclooxygenase-2 mRNA by RNA interference in bovine cumulus-granulosa cells     

Kobayashi S  Sakatani M  Kobayashi S  Okuda K  Takahashi M 《The Journal of reproduction and development》2007,53(6):1305-1311

Inhibition of specific gene expression using RNA interference (RNAi) is a valuable tool for functional analysis of a target gene. However, there is little information available concerning RNAi for analysis of gene function in relation to the reproductive physiology of follicular cells in ruminants. Thus, the aim of this study was to evaluate the interfering effect of small interference RNA (siRNA) on expression of cyclooxygenase-2 (Cox-2) mRNA and prostagrandin F(2alpha) (PGF(2alpha)) production in bovine cumulus-granulosa (CG) cells. Bovine CG cells were collected from aspirated follicles and cultured. After reaching confluency, two experiments were conducted. In experiment 1, to investigate the effective concentration of siRNA, 0, 100, 250 and 500 pM of Cox-2 siRNA was introduced into the CG cells, respectively. After 24 h, the amount of Cox-2 mRNA expression was measured by RT-PCR and real-time PCR. In experiment 2, to investigate the time required for effective interference of siRNA and Cox-2 activity, 250 pM siRNA was introduced for 0, 3, 6, 12 and 24 h. After culture, the amount of Cox-2 mRNA expression was measured and the culture medium was collected to determine the PGF(2alpha) concentration by enzyme immunoassay. The Cox-2 mRNA expression was not affected by introduction of 100 pM siRNA into CG cells for 24 h, but 250 and 500 pM Cox-2 siRNA significantly reduced the Cox-2 mRNA expression. Moreover, the significant suppressive effect of 250 pM siRNA was observed 6 h after introduction, and the reduction of mRNA expression by RNAi became more obvious over 12 h. On the other hand, the PGF(2alpha) concentration in the culture medium was not significantly different 12 h after siRNA introduction; however, the PGF(2alpha) concentration 24 h after siRNA introduction was significantly decreased compared with the control at the same time point. These results suggest that gene silencing of Cox-2 with siRNA is capable of analyzing the function and expression of specific genes in bovine CG cells.  相似文献   

Frequency of and risk factors for epistaxis associated with exercise-induced pulmonary hemorrhage in horses: 251,609 race starts (1992-1997)     

Takahashi T  Hiraga A  Ohmura H  Kai M  Jones JH 《Journal of the American Veterinary Medical Association》2001,218(9):1462-1464

OBJECTIVE: To determine the frequency of epistaxis during or after racing among racehorses and identify factors associated with development of epistaxis. DESIGN: Retrospective study. SAMPLE POPULATION: 247,564 Thoroughbred and 4,045 Anglo-Arab race starts. PROCEDURE: Race start information (breed, age, sex, racing distance, and race type) was obtained for Thoroughbred and Anglo-Arab horses racing in Japan Racing Association-sanctioned races between 1992 and 1997. All horses that raced were examined by a veterinarian within 30 minutes of the conclusion of the race; any horse that had blood at the nostrils was examined with an endoscope. If blood was observed in the trachea, epistaxis related to exercise-induced pulmonary hemorrhage (EIPH) was diagnosed. RESULTS: Epistaxis related to EIPH was identified following 369 race starts (0.15%). Frequency of EIPH-related epistaxis was significantly associated with race type, age, distance, and sex. Epistaxis was more common following steeplechase races than following flat races, in older horses than in horses that were 2 years old, following races < or =1,600 m long than following races between 1,601 and 2,000 m long, and in females than in sexually intact males. For horses that had an episode of epistaxis, the recurrence rate was 4.64%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that frequency of EIPH-related epistaxis in racehorses is associated with the horse's age and sex, the type of race, and the distance raced. The higher frequency in shorter races suggests that higher intensity exercise of shorter duration may increase the probability of EIPH.  相似文献   

Immunohistochemical detection of apolipoprotein B-100 and immunoglobulins (IgA, IgM, IgG) in the splenic arteries of aging dogs     

Sako T  Uchida E  Kagawa Y  Hirayama K  Takahashi T  Nakade T  Niiyama M  Izumisawa Y  Taniyama H 《Veterinary pathology》2001,38(4):407-413

Accumulation of lipids and hyalinosis in the splenic arteries of aged dogs are frequently detected by routine histopathologic examinations. The purpose of this study was to pinpoint the localization of canine apolipoprotein B-100 (CApoB-100) and immunoglobulins (IgA, IgM, IgG) in the splenic arteries of aging dogs (n = 80) through the use of immunohistochemical techniques. CApoB-100 deposits were found in the subendothelial space, extracellular matrix, and atheromatous lesions in the tunica media of the arteries in dogs > or = 6 years of age. Foamy cytoplasm of the infiltrated macrophages was also CApoB-100 immunopositive. In dogs > or = 10 years of age, almost all central arteries were CApoB-100 immunopositive. Hyaline deposits within the wall were characterized by immunopositivity against canine IgA, IgM, IgG, and albumin. Lipid accumulation in splenic arteries may be an age-related lesion and a precursor of the atheromatous plaques associated with splenic hemorrhage and infarcts later in life. In addition, deposition of immunoglobulins, probably mediated by immune complexes, may play an important role in the development of canine vascular diseases similar to human disease.  相似文献   

Changes in serum thyroid hormone levels in newborn calves as a diagnostic index of endemic goiter     

Takahashi K  Takahashi E  Ducusin RJ  Tanabe S  Uzuka Y  Sarashina T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(2):175-178

Maximum serum thyroxine (T4) and triiodothyronine (T3) levels of healthy calves were seen at 1 day after birth, and thereafter rapidly decreased until 5 days after birth. They stabilized until 2 weeks after birth, then gradually decreased until 4 weeks after birth. Serum T4 levels of calves with endemic goiter tended to be lower than those of healthy ones, but showed similar levels to those of adult cows. T3 levels of calves with goiter were similar to those of healthy ones, but showed higher variation. T4/T3 ratio of calves with goiter were significantly lower than those of healthy ones and adult cows. While individual levels of serum T4 and T3 at just after birth could not be considered as a diagnostic index, the T4/T3 ratio could be adopted as a diagnostic index of endemic goiter.  相似文献   

Mitotic disruption by a novel pyrimidine herbicide, NS-245852, in oat (Avena sativa L.) roots     

Akihiro Takahashi  Shigeo Yamada  Hirokazu Yamada  Takashi Kawana 《Weed Biology and Management》2001,1(3):182-188

The effects of a novel pyrimidine herbicide, NS-245852 [2-chloro-6-fluorophenyl-4-(trifluoromethyl)thieno[2,3-d]pyrimidine-2-yl-ketone], on mitosis in oat ( Avena sativa L. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10⁻⁷ mol L⁻¹ of NS-245852, and swollen root tips were induced at 5 × 10⁻⁸ mol L⁻¹. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS-245852 is the inhibition of polymerization of tubulin into microtubules.  相似文献   

Structural changes in intramuscular connective tissue during the fattening of Japanese black cattle: effect of marbling on beef tenderization   总被引：2，自引：0，他引：2  

Nishimura T  Hattori A  Takahashi K 《Journal of animal science》1999,77(1):93-104

We investigated changes in structures and mechanical properties of the intramuscular connective tissue during the fattening of Japanese Black steers, using the cell maceration method for scanning electron microscopy. During the early fattening period, from 9 to 20 mo of age, collagen fibrils of the endomysium in longissimus muscle associated more closely with each other, and collagen fibers in the perimysium increased in thickness and their wavy pattern became more regular. These changes were closely related to the increase in mechanical strength of the intramuscular connective tissue and resulted in a toughening of the beef during the period. The shear force value of longissimus muscle decreased after 20 mo of age, concomitantly with the rapid increase in the crude fat content. Scanning electron micrographs of the longissimus muscle dissected from 32-mo-old steers clearly showed that the adipose tissues were formed between muscle fiber bundles, that the honeycomb structure of endomysia was partially broken, and that the perimysium separated into thinner collagen fibers. In semitendinosus muscle, in which the crude fat content was lower (P<.05) than that in longissimus muscle, the structure of the intramuscular connective tissue remained rigid at 32 mo of age. The shear force value of the muscle increased even in the late fattening period, from 20 to 32 mo of age. Thus, the development of adipose tissues in longissimus muscle appears to disorganize the structure of the intramuscular connective tissue and contributes to tenderization of highly marbled beef from Japanese Black cattle during the late fattening period.  相似文献   

Evaluation of high sensitive DNA probe for the detection of Theileria sergenti infection in cattle.   总被引：2，自引：0，他引：2  

A Hirano  R Kirisawa  T Matsuba  R Komatsu  M Tanaka  K Takahashi  Y Kawakami  M Onuma 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(5):933-935

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Morphology and size of embryos recovered from superovulated cows.     

A Nakagawa  T Suzuki  T Suga  T Inoue  Y Takahashi  H Kanagawa 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(2):287-290

A total of 691 normal embryos were recovered from 183 superovulated donor cows on the 5th and 6th days after the first insemination, and were examined for their morphology and size in relation to their developmental stage. There was no significant difference in the thickness of the zona pellucida, the diameter of the cell mass, and the overall diameter of the embryos among zygotes, 2-, 4-, 8- and 16-cell embryos, and morulae. In the blastocyst stage, however, the diameter of the cell mass and the overall embryo diameter were significantly greater and the zona pellucida was significantly thinner than in the earlier-stage embryos. The volume of the blastomere significantly decreased from zygote to morula in proportion to the increase in the number of blastomeres. The volume of the cell mass of 2-cell embryos was decreased by about 30% compared with that of zygotes and no increase in the volume of the cell mass was observed during the progression from 2-cell stage to morula. The diameter of the cell mass and the overall diameter of morulae recovered on the 6th day after the first insemination were significantly greater than those of morulae recovered on the 5th day.  相似文献