Bovine Posterior Pituitary Extract Stimulates Prolactin Release from the Anterior Pituitary Gland In Vitro and In Vivo in Cattle     

T Hashizume  T Sasaki  S Nonaka  T Hayashi  M Takisawa  M Horiuchi  T Hirata  E Kasuya 《Reproduction in domestic animals》2005,40(2):184-189

It has been reported that the posterior pituitary (PP) gland contains a potent, unknown prolactin (PRL)-releasing factor (PRF) in rats. PRFs are assumed to be produced in neurones located within the hypothalamus, and to be peptidergic in nature. However, little is known about PRFs in domestic animals. To characterize the PRF in the PP of domestic animals, the present study examined the PRL-releasing activity of an acidic extract from bovine PP (bPP) in vitro and in vivo in cattle. First, the PRL-releasing effect of bPP extract was compared with that of PRL-releasing peptide (PrRP), and thyrotropin-releasing hormone (TRH) from cultured bovine anterior pituitary cells. The extract significantly increased PRL concentrations in the culture medium, at doses of 0.002 and 0.02 eq./ml (one eq. is the PP extract from one animal), compared with the control (p < 0.05). PrRP failed to stimulate the release of PRL. TRH significantly increased PRL concentrations in the culture medium, at doses from 10(-9) to 10(-7) M, compared with the control (p < 0.05). The rate of increase in the PRL concentration, by 0.02 eq./ml bPP extract, was significantly greater than that in TRH (p < 0.05). Secondly, plasma PRL responses to the intravenous (i.v.) injection of bPP extract (0.5 eq./head), PrRP [3.59 mug/kg body weight (BW)], TRH (1 mug/kg BW), and a dopamine receptor antagonist (sulpiride, 0.1 mg/kg BW), were examined in calves. PrRP failed to stimulate PRL release; however, plasma PRL increased immediately following the injection of bPP extract, TRH and sulpiride. The PRL-releasing effect of i.v. injections of TRH and sulpiride was more potent than that of bPP extract. Finally, plasma PRL responses to the intra-hypothalamic injection of bPP extract were examined in calves. The intra-hypothalamic infusion (arcuate nucleus) of 0.0625 eq./head of bPP extract strongly stimulated PRL release in calves (p < 0.05). The present results show that PP contains a physiologically potent PRF in cattle.  相似文献   

Sward characteristics,nutritive value and choice by cattle of conterminous monocultures of centipedegrass (Eremochloa ophiuroides) and bahiagrass (Paspalum notatum)          下载免费PDF全文

Masahiko Hirata  Toshiro Okuma  Yuichiro Tanaka  Manabu Tobisa 《Animal Science Journal》2016,87(5):674-680

In south‐western Japan, centipedegrass (Eremochloa ophiuroides; CG) offers a novel option for a warm‐season perennial for grazing use in areas where bahiagrass (Paspalum notatum; BG) can be grown. However, the potential of CG as a forage has not been fully explored because of the short history as a forage crop. We conducted four experiments to evaluate CG (cv. TifBlair) in comparison with BG (cv. Pensacola) in terms of sward characteristics, nutritive value and choice by animals. In each experiment, four Japanese Black cows (Bos taurus) were individually allowed to graze conterminous monocultures of CG and BG (5 × 10 m each) for 30 min. Irrespective of regrowth durations and fertilizer rates, CG was consistently shorter, leafier and denser, contained lower acid detergent fiber and cellulose, and was preferred or equally selected by cows, as compared with BG. Furthermore, CG maintained sufficient levels of crude protein (80–89 g/kg DM) to ensure voluntary intake of ruminant animals under extended regrowth^? and without fertilizer, whereas BG failed to do so (65 g/kg DM). CG provided higher digestible dry matter than BG when crude protein concentration exceeded 86 g/kg DM. The results indicate advantages of CG as a forage.  相似文献   

Changes in expression and localization of GPRC5B and RARalpha in the placenta and yolk sac during middle to late gestation in mice     

Imanishi S  Sugimoto M  Morita M  Kume S  Manabe N 《The Journal of reproduction and development》2007,53(5):1131-1136

The mRNA expression of GPRC5B, an orphan G protein-coupled receptor, is induced by retinoic acid (RA). Because RA plays critical roles in embryonic development, reproductive functions, metabolism and homeostasis, GPRC5B is also considered crucial in these physiological events. We investigated the changes in expression of GPRC5B and RA receptor (RAR) alpha mRNAs and immunohistochemical localization of their proteins in the murine placenta and yolk sac at 13.5, 15.5 and 17.5 days post coitus. Stable levels of GPRC5B and RARalpha mRNAs were detected in the placenta and yolk sac. In the placenta, GPRC5B was present in maternal and fetal vascular endothelial cells, stromal cells, fibroblast-like cells and glycogen cells. A strong reaction to RARalpha was detected in maternal and fetal vascular endothelial cells and stromal cells. The levels of GPRC5B and RARalpha proteins in maternal and fetal vascular endothelial cells decreased with gestation. In the yolk sac, GPRC5B and RARalpha proteins were detected in vascular endothelial cells, but their levels did not change during the gestation period. These findings indicate that GPRC5B is involved in RA-dependent morphogenesis/angiogenesis and regulation of extracellular matrix synthesis in the murine placenta and yolk sac.  相似文献   

Matrix-metalloproteinases-2 and -9 production in bovine endometrial cell culture   总被引：1，自引：0，他引：1  

Hashizume K  Takahashi T  Shimizu M  Todoroki J  Shimada A  Hirata M  Sato T  Ito A 《The Journal of reproduction and development》2003,49(1):45-53

In vitro cell culture is a convenient tool for studying cellular mechanisms. In the present study, production of matrix-metalloproteinases (MMPs) in bovine endometrial (containing both epithelial and stromal cells) monolayer cells was examined. Blastocysts attached to the endometrial cells in a monolayer culture were examined for their effects on MMP-2 production. Initial attachment of blastocysts to the monolayer inhibited MMP-2 production by endometrial cells. But once trophoblast cells began to migrate into the endometrial cell layer, MMP-2 production increased, and at the same time MMP-9 production also became evident in the medium. In order to understand how blastocysts affected MMP-2 production, we examined the effect of progesterone, estradiol, insulin-like growth factors (IGFs), tumor necrosis factors (TNFs), and interferon-tau (IFN-tau) supplementation. It was IFN-tau that inhibited the production of MMP-2. In addition, progesterone at a lower dose appeared to inhibit MMP-2 production. Both TNF-alpha and TNF-beta strongly stimulated the production of MMP-2 and MMP-9, whereas IGFs had no effect. Based on these findings, it appears that conceptus has the capacity to inhibit MMP activity.  相似文献   

Effects of 6-hydroxydopamine on the development of the immune system in chickens     

Motobu M  El-Abasy M  Na KJ  Vainio O  Toivanen P  Hirota Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(1):35-42

It has been suggested that the sympathetic nervous system communicates with lymphocytes expressing cell surface receptors for neurotransmitters such as norepinephrine (NE), on the basis of the finding that neurotransmitters modify immune responses in mammalian species. We confirmed that chicken lymphocytes in the brusa of Fabricius, thymus and spleen expressed beta-adrenergic receptor (beta-AR) mRNA from embryonic day (E) 10 and that intracellular cAMP level was elevated by NE, suggesting that lymphocytes express functional beta-AR on their surface at an early embryonal stage. To clarify whether the nervous system is involved in the development of the immune system, the effects of 6-hydroxydopamine (6-OHDA), one of sympathectomizing agents, on chicken lymphocytes was investigated. A single injection of 6-OHDA at a dose of 400 microg into a chicken embryo was carried out at E7 or 14 (as referred to E7 group and E14 group, respectively). NE level and the relative proportion of Bu-1a(+), CD4(+) and CD8(+) cells in the spleen of 3-week-old chickens were not altered by 6-OHDA treatment. However, the proliferative responses and expression of IL-2 mRNA in spleen cells cultured with pokeweed mitogen were reduced in E7 group compared with those of control. Furthermore, in CD8(+) spleen cells of E14 group of 3-week-old chickens, the expression of beta-AR mRNA and the relative increase of intracellular cAMP stimulated with NE were significantly decreased. These results suggest that the sympathetic nervous system affects the development of the immune system.  相似文献   

Protective effects of sugar cane extracts (SCE) on Eimeria tenella infection in chickens     

El-Abasy M  Motobu M  Na KJ  Shimura K  Nakamura K  Koge K  Onodera T  Hirota Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(8):865-871

The effects of oral administration of sugar cane extracts (SCE) on Eimeria tenella oocysts infection in chickens were studied with 2 different experiments. In Experiment 1, 3-week-old inbred chickens (MHC; H.B15) were inoculated into the crop with SCE (500 mg/kg/day) for 1 day or 3 consecutive days, and then challenged with E. tenella sporulated oocysts (2 x 10(4) cells/chicken). In Experiment 2, 1-week-old chickens were orally administered SCE at the same dose for 3 consecutive days, and then initially infected with E. tenella sporulated oocysts (2 x 10(3) cells/chicken). At 2 and 3 weeks of age, these chickens were immunized intravenously with the mixed antigens of sheep red blood cells (SRBC) and Brucella abortus (BA). At 4 weeks of age, chickens were challenged with E. tenella sporulated oocysts (1 x 10(5)/chicken). Challenged chickens with E. tenella oocysts showed markedly decreased body weight gain/day, severe hemorrhage and great number of shedding oocysts in feces and high lesion scores. Oral administration of SCE and initial infection with oocysts (2 x 10 (3)/chicken) resulted in a remarkable improvement in body weight gain/day, hemorrhage, the number of shedding oocysts and lesion score, compare to other infected groups. In addition, SCE-inoculated chickens with the initial infection showed a significant increase in antibody responses against SRBC and BA and also improvement in decreased relative proportions of Bu-1a(+) and CD4( )cells in cecal tonsil lymphocytes of E. tenella-challenged chickens. Cecal tissues of chickens administered SCE and initially infected with E. tenella oocysts showed lower numbers of schizonts, gametocytes and oocysts than those of infected control chickens. These results suggest that SCE have immunostimulating and protective effects against E. tenella infection in chickens.  相似文献   

Effects of a high-protein diet versus dietary supplementation with ammonium chloride on struvite crystal formation in urine of clinically normal cats     

Funaba M  Yamate T  Hashida Y  Maki K  Gotoh K  Kaneko M  Yamamoto H  Iriki T  Hatano Y  Abe M 《American journal of veterinary research》2003,64(8):1059-1064

OBJECTIVE: To evaluate the effects of a high-protein diet versus dietary supplementation with ammonium chloride (NH4Cl) on struvite crystal formation in the urine of clinically normal cats by measuring the urine concentration of hydrochloric acid (HCl)-insoluble sediment, urine pH, struvite activity product (SAP), number of struvite crystals in urine, and urine volume. ANIMALS: 23 healthy adult cats. PROCEDURE: Urine was fractionated by centrifugation with subsequent extraction of the sediment with 1 N HCl (study 1). Diets containing either 29% crude protein or 55% crude protein were fed to cats in a crossover trial of 3 weeks/period (study 2). Diets supplemented with either sodium chloride (NaCl) or NH4Cl were fed, by use of a 3 x 3 Latin-square design with 3 wk/period (study 3). In studies 2 and 3, urine samples were collected for the last 7 days of each period. RESULTS: The HCl-insoluble sediment contained Tamm-Horsfall glycoprotein (THP; study 1). The high-protein diet (study 2) and dietary supplementation with NH4Cl (study 3) resulted in a decrease in urine pH, SAP, and the number of struvite crystals in urine. However, the high-protein diet decreased urine concentrations of HCl-insoluble sediment containing THP (study 2), in contrast to the NH4Cl supplementation that increased urine volume without a significant effect on the urine concentration of the HCl-insoluble sediment (study 3). CONCLUSIONS AND CLINICAL RELEVANCE: Our results indicate that compared with dietary supplementation with NH4Cl, the high-protein diet is preferable as a urine acidifier for the prevention of struvite crystal formation in clinically normal cats.  相似文献   

Is AZT/3TC therapy effective against FIV infection or immunopathogenesis?     

Arai M  Earl DD  Yamamoto JK 《Veterinary immunology and immunopathology》2002,85(3-4):189-204

In vitro and in vivo prophylactic and therapeutic efficacy of AZT/3TC treatment was evaluated against feline immunodeficiency virus (FIV) infection. In vitro studies utilized FIV-infected peripheral blood mononuclear cells (PBMCs) or FIV-infected T-cell lines treated with AZT (azidothymidine) alone, 3TC alone, or AZT/3TC combination and tested for anti-FIV activity and drug toxicity. AZT/3TC combination had additive to synergistic anti-FIV activities in primary PBMC but not in chronically infected cell lines. In vivo studies consisted of four treatment groups (n=15) of SPF cats receiving AZT/3TC combination (5-75 mg/kg/drug PO BID for 8 or 11 weeks) and one control group (n=9) receiving oral placebo. Group I (n=6, 150 mg/kg/drug/day) was treated starting 3 days pre-FIV inoculation, whereas Group II (n=3, 150 mg/kg/drug/day) and Group III (n=3, 100 mg/kg/drug/day) treatments were simultaneous with FIV inoculation. Group IV treatment (n=3, 100 mg/kg/drug/day) was initiated 2 weeks post-FIV inoculation. All cats were monitored for drug toxicity and FIV infection. Eighty-three percent of cats in Group I and 33% of cats in Groups II and III were completely protected from FIV infection. A significant delay in infection and antibody seroconversion was observed in all unprotected cats from Groups I, II and III. Group IV cats had only a slight delay in FIV antibody seroconversion. Adverse drug reactions (anemia and neutropenia) were observed at high doses (100-150 mg/kg/drug/day) were reversible upon lowering the dose (20 mg/kg/drug/day). In contrast, AZT/3TC treatment had no anti-FIV activity in chronically infected cats. Furthermore, severe clinical symptoms caused by adverse drug reactions were observed in some of these cats. Overall, AZT/3TC treatment is effective for prophylaxis but not for therapeutic use in chronically FIV-infected cats.  相似文献   

Detection of mitogen-induced lymphocyte proliferation by bromodeoxyuridine (BrdU) incorporation in the chicken   总被引：2，自引：0，他引：2  

Motobu M  El-Abasy M  Na KJ  Hirota Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):377-379

3H-thymidine (3H-TdR) incorporation assay has been generally used to measure lymphocyte proliferation in the chicken. Disadvantages of this assay are that radioisotope is biological hazard to the person and environment and that it can not measure which subset of lymphocytes proliferates. In this study, bromodeoxyuridine (BrdU) incorporation assay by flow cytometry was compared with 3H-TdR incorporation assay. As a result, BrdU incorporation assay showed a strong correlation with 3H-TdR incorporation assay, and it could be applied simultaneously to detect BrdU incorporation and expression of cell surface marker antigens. These results suggest that the BrdU incorporation assay by flow cytometry is useful to analyze lymphocyte proliferation in detail.  相似文献   

Immunostimulating and growth-promoting effects of sugar cane extract (SCE) in chickens     

El-Abasy M  Motobu M  Shimura K  Na KJ  Kang CB  Koge K  Onodera T  Hirota Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(11):1061-1063

Polymorphonuclear cells of the peripheral blood in the chicken significantly increased their phagocytosis when cultured with sugar cane extract (SCE; 250-1,000 microg/ml) for 24 hr. Chickens orally administered SCE (500 mg/kg/day) for 3 or 6 consecutive days at 1 week of age showed significantly higher body weight and gain in body weight/day and a lower food conversion ratio within the growing period of 6 weeks than physiological saline-administered control chickens. Furthermore, oral administration of SCE also resulted in significantly higher immune responses against sheep red blood cells and Brucella abortus. These results suggest that SCE has immunostimulating and growth promoting effects in chickens.  相似文献