排序方式： 共有35条查询结果，搜索用时 546 毫秒
1.
Lucia T Corrêa MN Deschamps JC Bianchi I Donin MA Machado AC Meincke W Matheus JE 《Preventive veterinary medicine》2002,53(4):57-292
We evaluated stillbirth risk factors in two commercial swine farms of the Rio Grande do Sul State (south of Brazil). The study was conducted during 1 month in Farm A and during 2 months in Farm B, both during 1999. Data for all farrowings that occurred during the study period were recorded (101 for Farm A and 373 for Farm B), without interference in the farm management. In Farm A, 39% of all litters born during the period of interest had stillborn piglets and the stillborn risk for piglets was 12%. In Farm B, 25% of all litters had stillborn piglets whereas the stillborn risk was 2%. Variables considered as potential risk factors for stillbirths were: parity (1, 2–3, 4+); breed (purebred or crossbred); sow body-condition (normal or fat); use of oxytocin during parturition (yes or no); obstetric intervention through vaginal palpation (yes or no); farrowing duration (<4 or ≥4 h); mummified fetuses (yes or no); total litter size (<12 or ≥12 piglets); and litter birth weight (<11 or ≥11 kg). All stillborn piglets had their classification validated by necropsy. In multivariable logistic-regressions, the cases were the litters having at least one stillborn piglet. In Farm A, litters having at least 12 pigs and in which oxytocin was used during the parturition had 20.8-times-higher odds of stillborn occurrence. In Farm B, litters from sows having parity ≥4 had 2.2-times-higher odds of stillborn occurrence than litters from parity 2 to 3 females, litters having ≥12 pigs had 2.0-times-higher odds of a stillborn piglet than smaller litters and farrowings in which vaginal palpation was performed had 8.0-times-higher odds. Farrowing room management to minimize stillborn risk should target higher-parity females, large litters and optimization of practices of obstetric interventions. 相似文献
2.
Kazumasa HONDA Ayako SUDO Kentaro IKEDA 《The Journal of reproduction and development》2013,59(6):569-574
The present experiments were undertaken to examine whether oxytocin cells in the
supraoptic nucleus receive synaptic inputs from the contralateral supraoptic nucleus
or paraventricular nucleus. Using urethane-anesthetized lactating rats, extracellular
action potentials were recorded from single oxytocin or vasopressin cells in the
supraoptic nucleus. Electrical stimulation was applied to the contralateral
supraoptic nucleus or paraventricular nucleus, and responses of oxytocin or
vasopressin cells were analyzed by peri-stimulus time histogram or by change in
firing rate of oxytocin or vasopressin cells. Electrical stimulation of the
contralateral supraoptic nucleus or paraventricular nucleus did not cause antidromic
excitation in oxytocin or vasopressin cells but caused orthodromic responses.
Although analysis by peri-stimulus time histogram showed that electrical stimulation
of the contralateral supraoptic nucleus or paraventricular nucleus caused orthodromic
excitation in both oxytocin and vasopressin cells, the proportion of excited oxytocin
cells was greater than that of vasopressin cells. Train stimulation applied to the
contralateral supraoptic nucleus or paraventricular nucleus at 10 Hz increased firing
rates of oxytocin cells and decreased those of vasopressin cells. The results of the
present experiments suggest that oxytocin cells in the supraoptic nucleus receive
mainly excitatory synaptic inputs from the contralateral supraoptic nucleus and
paraventricular nucleus. Receipt these synaptic inputs to oxytocin cells may
contribute to the synchronized activation of oxytocin cells during the milk ejection
reflex. 相似文献
3.
综述了催产素(OT)、精氨酸加压素(AVP)、性激素(包括雌激素、孕酮、雄性激素)这些神经激素与啮齿类动物的社会识别关系的研究进展。 相似文献
4.
青年奶山羊下丘脑催产素神经元分布特点 总被引：14，自引：1，他引：13
为了研究奶山羊不同生殖周期中催产素的表达特点,本实验采用超敏免疫组化链霉素抗生物蛋白－过氧化物酶法研究催产素免疫反应物在8~10月龄青年龄奶山羊下丘脑的分布。结果显示：分泌催产素的神经元主要分布在室旁核和视上核,在穹窿周核、腹内侧核、腹外侧核、交叉上核和乳头体上核较多,有少量分布在弓状核、室周核、背内侧核、环核、前连核、下丘脑前核、下丘脑外侧区、乳头体上核、乳头体内侧核。阳性细胞的形态有圆形、卵圆形、多角形;有的阳性细胞突起明显。根据细胞中阳性物质的多少和核团中阳性细胞数量,可分为强阳性、中等阳性、弱阳性核团。提示：催产素广泛存在于青年奶山羊下丘脑中20多个核团,核团之间可能有协同作用。 相似文献
5.
Non-genomic actions of progesterone and estrogens in regulating reproductive events in domestic animals 总被引：1，自引：1，他引：0
It has been established that nuclear receptors mediate the action of estrogens and progestins in regulating gene expression in the hypothalamic-hypophyseal-gonadal axis of domestic animals during various reproductive states. Results of recent in vitro studies suggest that estradiol-17beta and progesterone can act non-genomically to affect signal transduction responses in target cells by binding to receptors in the plasma membrane. The genomic action of steroids is generally detectable in hours to days whereas non-genomic responses of cells occur in seconds to minutes. The nature of the plasma membrane receptors for estrogens and progesterone has been explored but has not been conclusively established for all cell types studied. In the ewe, estradiol-17beta or estradiol-bovine serum albumin conjugate has been shown by in vitro and in vivo approaches to act non-genomically to suppress luteinizing hormone secretion by gonadotropes and stimulate production of nitric oxide by uterine arterial endothelial cells. Progesterone has been shown to inhibit oxytocin (OT) binding to its receptor in isolated ovine endometrial plasma membranes. This non-genomic action of progesterone blocks OT activation of the phosphoinositide cascade and production of prostaglandin F(2alpha) by ovine and bovine endometrium. The acrosome reaction of caprine and porcine spermatozoa is activated by the non-genomic action of progesterone. Further research is required to define the biological significances of the non-genomic actions of estrogens and progestins. 相似文献
6.
从催产素的作用机理入手,总结了催产素在奶牛助产、预防和治疗胎衣不下、治疗子宫迟缓、治疗子宫内膜炎和子宫积脓、催乳、治疗持久性黄体不孕症、提高受胎率等方面的应用情况和注意事项。 相似文献
7.
Mares give birth under high parasympathetic tone as indicated by increased heart rate variability (HRV) and atrioventricular blocks. These changes might be induced by oxytocin released at foaling. In this short communication, the cardiac (n = 4) and cortisol response (n = 3) of mares treated with oxytocin infusions because of fetal membrane retention are reported. A marked cortisol release occurred during oxytocin infusion in two mares but not in a third mare which was infused for 6 minutes only. Oxytocin-induced cortisol release was neither accompanied by an increase in heart rate nor a decrease in HRV, and heart rate even decreased during oxytocin infusions. Preliminary data indicate that cortisol release in oxytocin-treated mares is not a stress response. Treatment of retained membranes in mares with oxytocin does not induce cardiovascular side effects. 相似文献
8.
9.
由《园艺学报》编辑部和中国农业科学院蔬菜花卉研究所生物技术研究室共同发起和主办的“信息园艺学论坛”于2007年5月28～29日在成都举行。 相似文献
10.
催产素对家蚕产卵性能的影响 总被引：1，自引：0，他引：1
本试验以中国系统种夏芳为材料,用医用催产素对雌蛹、母蛾进行喷雾法和雌蛹瞬时浸渍法处理。调查了母蛾产卵速度、产卵数、产出卵率及不受精卵率,探讨了催产素对母蛾产卵的作用效果。结果表明催产素处理雌蛹或母蛾对产出卵率有降低的趋势,对不受精卵率影响不显著,但能显著提高产卵速度。 相似文献