Growth hormone suppresses the expression of IGFBP-5, and promotes the IGF-I-induced phosphorylation of Akt in bovine mammary epithelial cells     

Sakamoto K  Yano T  Kobayashi T  Hagino A  Aso H  Obara Y 《Domestic animal endocrinology》2007,32(4):260-272

Growth hormone (GH) plays a specific role to inhibit apoptosis in the bovine mammary gland through the insulin-like growth factor (IGF)-I system, however, the mechanism of GH action is poorly understood. In this study, we show that GH dramatically inhibits the expression of IGFBP-5, and GH along with IGF-I enhanced the phosphorylation of Akt through the reduction of IGF binding protein (IGFBP)-5. To determine how GH affects Akt through IGF-I in bovine mammary epithelial cells (BMECs), we examined the phosphorylation of Akt in GH treated BMECs and found that IGF-I induced phosphorylation of Akt was significantly enhanced by the treatment with GH. We demonstrated that GH reduces mRNA and protein expression of IGFBP-5 in BMECs, but it does not affect the expression of IGFBP-3. To determine that the enhanced effect of the Akt phosphorylation by the treatment of GH is due to the inhibition of the expression of IGFBP-5, we examined the effect of IGFBP-3 and -5 on the phosphorylation of Akt through IGF-I in the GH-treated BMECs. The phosphorylation of Akt was inhibited in a dose-dependent manner when IGFBP-5 was added at varying concentrations and was also inhibited in the presence of IGFBP-3. The results of this study suggest that GH plays an important role on mammary gland involution in bovine mammary epithelial cells.  相似文献   

Post-molt processes of cuticle formation and calcification in the Japanese mitten crab <Emphasis Type="Italic">Eriocheir japonicus</Emphasis>     

Konomi Sakamoto  Wataru Honto  Masaharu Iguchi  Nobuhiro Ogawa  Kazuhiro Ura  Yasuaki Takagi 《Fisheries Science》2009,75(1):91-98

This study examines the following in the Japanese mitten crab: (1) the structure of the exoskeleton with special reference to its calcification; (2) the progression of post-molt cuticle formation and calcification. In the crab, the structure and calcification state of the exoskeleton at the molt and during the inter-molt stage were similar to those of other crustaceans. During the inter-molt, the exoskeleton consisted of four cuticle layers; the outermost epicuticle, the exocuticle, the endocuticle and the innermost membrane layer. Intense calcification was observed in the exo- and endocuticle. At the molt, the synthesis of the epi- and exocuticle was already complete, and the addition of the endocuticle began after the molt. Calcification of the exocuticle initiated soon after the molt, but there was a delay between endocuticle matrix synthesis and calcification. Histology showed that the process of calcification was similar to that in other crustaceans. However, calcium concentrations within the exoskeleton continued to increase and never reached the levels of the inter-molt stage at the end of the experiment. This suggests that the Japanese mitten crab is relatively slow to calcify compared to other crustaceans.  相似文献   

Turnover time of microbial biomass carbon in Japanese upland soils with different textures     

Kazunori Sakamoto  Naoko Hodono 《Soil Science and Plant Nutrition》2013,59(2):483-490

We investigated the turnover time of microbial biomass-C in Japanese upland soils with various textures and examined the soil physicochemical properties influencing their turnover time. Samples from five different soil types (sand-dune regosol, light-colored Andosol, humic Andosol, brown forest soil, and dark red soil) were taken from upland concrete-frame plots in the experimental field of Chiba University. Each soil amended with [U -¹³C] glucose was incubated for 80 d at 25°C. Microbial biomass-C and -¹³C in soil were periodically determined by the fumigation-extraction method. The longest turnover time of microbial biomass-C was observed in the dark red soil (215 d) followed by the humic Andosol (134 d), brown forest soil (97 d), and light-colored Andosol (83 d) and the shortest in the sand-dune regosol (45 d). The turnover time of microbial biomass-C was significantly correlated with the value of soil clay (R: 0.917*), CEC (R: 0.921*), and macroaggregate (R: 0.907*) contents, but not with the total-C content. The amount of microbial biomass-C showed a close correlation with the turnover time of microbial biomass-C, suggesting that the turnover time of microbial biomass-C is an important factor influencing the accumulation of microbial biomass-C in soil.  相似文献   

Plant species identification using fecal DNAs from red-eared slider and Reeves’ pond turtle in agricultural canals for rural ecosystem conservation     

Noriyuki Koizumi  Atsushi Mori  Takuya Mineta  Eiji Sawada  Keiji Watabe  Takeshi Takemura 《Paddy and Water Environment》2017,15(4):723-730

Fecal DNA samples from the red-eared slider and Reeves’ pond turtle, suspected pests of lotus root paddies, were used to identify the plant species eaten by these turtles in order to develop a strategy for rural ecosystem conservation. The fecal samples were obtained from young and adult individuals (mostly female) of both species living in agricultural canals surrounding lotus root paddies in Tokushima Prefecture, Japan. The samples were screened for the presence or absence of DNA from nine plant species using PCR and plant species-specific primers for the rbcL gene of chloroplast DNA. In the red-eared slider, our analysis identified seven plant species in the fecal DNA samples of adults and three plant species in those of young individuals. In Reeves’ pond turtle, our analysis identified two plant species from adult fecal samples and one species from those of young individuals. Thus, adult red-eared sliders consume a greater range of plants than young red-eared sliders or Reeves’ pond turtles. Both turtle species, independently of age, consumed lotus plants and were likely to cause feeding damage to lotus roots. Considering the plant species detected in adult red-eared sliders and these plant habitats, we suggest that this adult turtle is likely to travel between the agricultural canals and the lotus root paddies. These findings will help the development of strategies for preventing damage to lotus roots by these turtles; furthermore, they indicate that fecal DNA analysis will be applicable to investigation of the feeding habits of other animal species.  相似文献   

Blood chemistry values of juvenile red pacu (Piaractus brachypomus)     

Sakamoto K  Lewbart GA  Smith TM 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2001,30(2):50-52

Abstract: Blood samples were collected from 29 juvenile red pacu ( Piaractus brachypomus ), ornamental freshwater fish, to establish baseline blood chemistry values. Mean (minimum-maximum) values, obtained by automated bichromatic analysis and ion selective electrode analysis, were as follows: sodium, 150.4 (146–159) mmol/L; potassium, 3.93 (2.7–5.0) mmol/L; chloride, 138.7 (128–150) mmol/L; total CO₂, 7.5 (6–10) mmol/L; albumin, 0.86 (0.5–1.0) g/dL; lactate dehydrogenase, 237.8 (65–692) IU/L; aspartate aminotransferase, 49.1 (0–125) IU/L; creatinine, 0.31 (0.2–0.4) mg/dL; calcium, 10.80 (9.5–12.5) mg/dL; anion gap, 6.89 (1.2–12.5) mmol/L; and phosphorus, 7.29 (4.1–8.9) mg/dL.  相似文献   

Changes in sexual behavior and fecal steroid hormone concentrations during the breeding season in female Hokkaido brown bears (Ursus arctos yesoensis) under captive condition     

Ishikawa A  Sakamoto H  Katagiri S  Takahashi Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(1):99-102

The longitudinal changes in fecal steroid hormone concentrations and sexual behavior in 2 mated/pregnant and 3 non-mated female Hokkaido brown bears were investigated during the breeding season. Behavioral estrus (standing) lasted for 14 and 32 days in the mated females and for 25 to 36 days in the non-mated females. In non-mated females, sexual behavior, such as female-female mounting and masturbation, was observed for several days before and after the estrous period. In mated females, mean fecal estradiol-17beta concentrations were higher in the estrous period than in the post-estrous period, while fecal progesterone concentrations were higher in the post-estrous period than in the estrous period. The similar trends of steroid hormone changes were observed in the non-mated females.  相似文献   

Effects of propofol-sevoflurane anesthesia on the maternal and fetal hemodynamics blood gases, and uterine activity in pregnant goats   总被引：2，自引：0，他引：2  

Setoyama K  Shinzato T  Misumi K  Fujiki M  Sakamoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(10):1075-1081

To determine the effects of propofol and sevoflurane on hemodynamics, acid-base balance and uterine activity in pregnant animals, a prospective experimental study was designed by use of ten pregnant goats. Propofol was intravenously administered at a bolus dose of 5 mg/kg and then infused a rate of 0.3 mg/kg/min for 5 min. Following the induction, the animals were incrementally inhaled 2.7 and 4.1% of end-tidal concentration of sevoflurane each for 30 min, and then recovered. The maternal and fetal heart rate (HR), arterial blood pressure (BP) and acid-base balance, the intrauterine pressure (IUP), and the uterine blood flow (UBF) were measured. Following the pre-anesthetic data, the parameters were measured 7 times throughout the anesthetic and recovering periods. The propofol infusion induced 1.37 times of HR increase and produced decrease in PO(2) and a relevant metabolic acidemia in the mother, with no effect in the fetus. Sevoflurane reduced BP in the fetus from 30 (2.7%) to 60 (4.1%) min of inhalation. The uterine contractions disappeared throughout sevoflurane inhalation, and then recurred within 15 min after the cessation of sevoflurane. Propofol injection increases HR, and induces a moderate hypoxemia and metabolic acidemia associated with the suppressed ventilation for pregnant goats, with less effect on the fetal hemodinamics. Sevoflurane causes minimal change in maternal hemodynamics, but induces significant hypotension in the fetus and reduction of uterine activity. These data may be useful in making anesthetic choices combined with analgesia for Caesarian section in goats.  相似文献   

Effects of milrinone on hemodynamics and regional blood flow in the hypoxic dog   总被引：2，自引：0，他引：2  

Setoyama K  Ota H  Miura N  Fujiki M  Misumi K  Sakamoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(6):499-503

Milrinone, a therapeutic agent for acute congestive heart failure, has both inotropic and vasodilatory effects, but investigations of these effects of milrinone were almost all conducted under normoxia, and few reports have investigated how milrinone affects the hemodynamics and redistribution of regional blood flow under severe hypoxia. By using colored microspheres, we investigated how milrinone affects hemodynamics and the redistribution of regional blood flow under severe hypoxia. Twelve healthy mongrel dogs were divided into 2 groups. The milrinone group was infused with milrinone cumulatively at 25, 75 and 250 microg/kg for 5 min each. The intact group was infused with saline instead of milrinone. We measured the hemodynamics and cerebrum, cerebellum and kidney blood flow in both groups. Both groups were inspired with 10% oxygen. Milrinone induced significant decrease in mean pulmonary artery and pulmonary vascular resistance, compared with the intact group. In both groups slight decreases in mean arterial pressure, systemic vascular resistance and double-product were seen. In regional blood flow, milrinone-induced increases in blood flow were seen in the cerebrum, cerebellum, and especially in the kidneys. Milrinone's vasodilatory effects were sufficient even under hypoxia. And milrinone increased regional blood flow slightly in the cerebrum and cerebellum, and significantly in the kidneys. These results suggested that milrinone protects against hypoxia-induced organ damage especially in the kidneys. In addition, milrinone is very potent in improving severe congested hemodynamics which complicates hypoxic pulmonary vasoconstriction.  相似文献   

Age-related changes of genital systems in the female Crj:CD (SD) IGS rats during sexual maturation     

Noda S  Sawaki M  Shiraishi K  Yamasaki K  Yamaguchi R 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):315-319

The age-related changes of vaginal opening, body weight, the weights of the uterus and ovary, together with histological examination, serum 17beta-estradiol (E2) and progesterone levels were examined in intact female Crj:CD (SD) IGS rats between 21 and 36 days of age to understand the basic biological profile of changes of the female genital system during sexual maturation in the rat for female pubertal assays. With the beginning of the elevation of serum E2 level from 28 days of age, all parameters except body weight started to show drastic change until 31 days of age. The highest incidence of vaginal opening was recorded at 34 days of age. On macroscopic examinations, a number of rats showed uterine imbibition but vaginal opening. Immediately after the confirmation of the vaginal opening, the genital systems of three rats were observed microscopically. Both ovaries already had multiple corpora lutea, and degeneration of endometrial epithelial cells was observed. In conclusion, we obtained essential data on genital tract development of female Crj:CD (SD) IGS rats for in vivo screening assays that will contribute to detect potential endocrine active chemicals. In addition, it is assumed that the first ovulation precedes or occurs simultaneously with vaginal opening.  相似文献   

Serum activities of tartrate-resistant acid phosphatase and bone specific alkaline phosphatase as indices of bone metabolism in the cow     

Sato J  Okada K  Fukuda S  Sato R  Yasuda J  Naito Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(7):653-655

The correlation between the serum hydroxyproline concentration and serum activity levels of TRAP and BALP was examined in 41 cows. The correlated coefficient (r) was 0.6391 for TRAP and 0.3147 for BALP, respectively. Judging from the significant correlation to the serum hydroxyproline concentration, serum TRAP activity is an index for bone metabolism in cows. Serum TRAP activity was therefore measured in 205 healthy cows (2-9 years old) in order to observe the changes in bone resorption with aging and milk production. TRAP levels differed slightly between group A (< or =4 yrs) and B (5 yrs< or =) at the same stage of lactation. The activity levels rose slightly at the height of lactation stage and during the dry stage.  相似文献