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31.
传统上认为母乳能提供足量的氨基酸保证仔猪生长的生长需要,但当母乳是唯一的蛋白质来源时,哺乳仔猪的生长性能不能达到最佳。估计在7日龄的哺乳仔猪中,猪乳提供的精氨酸≤40%的每天需要量。精氨酸是哺乳仔猪的必需氨基酸,有提高仔畜生长的巨大的潜能;它在氨通过肝尿素循环降解中起重要作用,是NO合成的生理物质,因此有必要进一步阐明在母猪哺育的仔猪中缺乏精氨酸的机制,促进新生仔猪的精氨酸营养和生长。 相似文献
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AIM: To investigate the changes of the renal L-arginine /nitric oxide pathway and the relationship of L-arginine transport between kidney and erythrocytes in spontaneously hypertensive rat (SHR). METHODS: Sixteen week old SHR, 16 week old SHR with captopril (CAP) treated for four weeks and 16 week old WKY rats were used in the experiment. L-arginine transport, NO synthase(NOS) activity, nitrite and cyclic GMP (cGMP) content were measured in renal tissue or erythrocytes. RESULTS: In the renal tissue, compared with that of WKY group, the Vmax of high-or low-affinity L-arginine transporter, NOS activity, NO2- and cGMP content of SHR group were significantly decreased (P<0.01 or P<0.05). The Vmax of high-affinity L-arginine transporter and NOS activity of CAP group were significantly enhanced as compared with SHR group (+90%, P<0.01; +58.6%, P<0.05). The NOS activity had significant positive correlation with the Vmax of high-affinity L-arginine transporter (r=0.585, P<0.05). The changes of erythrocyte L-arginine transport were the same as that of kidney. The Vmax of SHR group was lower than that of WKY group (-30%, P<0.01), and the Vmax of CAP group was higher than that of SHR group (+26.5%, P<0.01). Km was not significantly changed. There is a positive correlation between the Vmax of L-arginine transport in erythrocyte and the Vmax of high- or low-affinity L-arginine transporter in renal tissue, (r=0.8434, P<0.01, high-affinity; r=0.5255, P<0.05, low-affinity). CONCLUSION: There existed a functional inhibition in L-arginine/nitric oxide pathway in the kidney of SHR. It can be recovered obviously by captopril treatment. The changes of L-arginine transport in kidney coincide with that in erythrocyte. 相似文献
34.
TANG Yu SUN Shi-lin YIN Shuang-shuang PENG Zhe-yu ZENG Xian-gang YAO Shu-ting HE Yu-ting PENG Na 《园艺学报》2019,35(3):479-484
AIM: To investigate the effects of arginine vasopressin (AVP) on the expression and phosphorylation of γ-aminobutyric acid (GABA) subtype A receptor (GABAA receptor) subunits in the preoptic area (POA) of rats. METHODS: The rats were divided into AVP group (n=10), AVP+V1a receptor blocker group (n=10), V1a receptor blocker group (n=10) and control group (n=10). After intraperitoneal injection of AVP or V1a receptor antagonist for 0.5 h, the changes of the expression and phosphorylation of POA GABAA receptor subunits (α, β and γ2) were analyzed by RT-qPCR and Western blot. RESULTS: Compared with control group, no significant change of GABAA receptor subunit expression in the rats injected with AVP or V1a receptor antagonist was observed. AVP up-regulated the phosphorylation level of POA GABAA receptor γ2 subunit (P<0.05), and significantly increased the expression and phosphorylation of protein kinase C (PKC) and calcium/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ). CONCLUSION: Exogenous AVP has no effect on expression of POA GABAA receptor subunits (α, β and γ2) and is involved in modulation of GABAergic synaptic transmission in the POA by activation of PKC and CaMKⅡ and phosphorylation of γ2 subunit via V1a receptor. 相似文献
35.
AIM: To investigate the relationship between motion sickness and the plasma levels of stress-related hormones in the rats before and after vestibular training.METHODS: Conditioned taste aversion (CTA) was induced in 72 female SD rats after rotatory stimulation. The magnitude of CTA was measured to reflect the susceptibility of rats to motion sickness. The plasma levels of corticosterone, adrenocorticotrophic hormone (ACTH), corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) were analyzed by radioimmunoassay. Hormone levels were determined before and after rotatory stimulation, and after 1 month of vestibular training when the rats obtained habituation to this rotation.RESULTS: CTA to 0.15% saccharin solution in rats after the rotatory stimulation was completely inhibited after vestibular training, suggesting that a habituation of the rats to motion sickness was obtained. The rotatory stimulation induced an elevation in the plasma levels of corticosterone, ACTH and AVP, and this response of corticosterone to rotation was greatly reduced after vestibular training. The plasma levels of all 4 hormones in the rats insusceptible to motion sickness were higher than those in susceptible group, especially the plasma levels of corticosterone and ACTH after rotation, and the basal level of CRH. In addition, after vestibular training, the basal plasma levels of corticosterone, ACTH and CRH in both groups were higher than those before training, and a slight elevation was also observed in the basal level of AVP.CONCLUSION: Vestibular training may induce a habituation to rotatory stimulation in rats, thus inhibiting the development of motion sickness. The difference of the susceptibility of rats to motion sickness may negatively relate to the basal plasma levels of stress-related hormones. 相似文献
36.
AIM:To determine the effect of different ambient temperatures on arginine vasopressin (AVP)-induced hypothermia in rats and its relationship with the change of heat loss from the tail, and to assess if peripheral AVP administration increases heat loss from the tail. METHODS:The core temperature and tail skin temperature in adult male Sprague-Dawley rats at three different ambient temperatures (12 ℃, 22 ℃ and 32 ℃) were monitored by wireless telemetry. The rats were intraperitoneally injected with AVP (10 μg/kg) or vasopressin V1a receptor antagonist (30 μg/kg) at 10:00 AM. The diameters of microvessels in the spinotrapezius muscle and the grooming behavior in the rats were also observed after treatment with AVP or vasopressin V1a receptor antagonist. RESULTS:AVP-induced hypothermia in the rats at three ambient temperatures was accompanied by a decrease in tail skin temperature. V1a receptor antagonist attenuated the hypothermia and the decrease in tail skin temperature induced by AVP (10 μg/kg). AVP induced significant constriction of the microvessels in the spinotrapezius muscle. AVP also enhanced the grooming behavior (salivary grooming) in the rats and this effect was inhibited by peripheral administration of vasopressin V1a receptor antagonist. Endogenous AVP did not mediate the heat loss from the tail in normal rats. CONCLUSION:Peripheral AVP induces hypothermia in rats. It does not lower the set point of body temperature, and its hypothermic effect may attribute to the suppression of thermoregulatory heat production and the increase in salivary grooming (saliva spreading for evaporative heat loss). 相似文献
37.
Camilo Pohlenz Alejandro Buentello Stå le J Helland Delbert M Gatlin III 《Aquaculture Research》2014,45(3):491-500
Juvenile channel catfish Ictalurus punctatus were fed casein–gelatin‐based semi‐purified test diets with graded amounts of arginine (ARG, 0.5%, 1%, 2% and 4% of dry diet) for a 6‐week period, to evaluate the effects of dietary ARG supplementation on performance indicators, levels of plasma ARG, ornithine, citrulline, glutamine and glutamate, as well as selected innate immune parameters. Incremental dietary ARG resulted in significant improvements in weight gain, feed efficiency and protein efficiency ratios, protein retention, protein deposition and arginine deposition. Fish fed the 4% ARG diet had significantly higher values for all performance indicators, although these values were not different from those of fish fed the 2% ARG diet with the exception of protein retention, protein deposition and arginine deposition. Conversely, fish fed the 0.5% ARG diet had significantly lower values for all analysed plasma amino acids. Similarly, both phagocyte superoxide anion production and neutrophil respiratory burst were significantly decreased in fish fed the 0.5% ARG diet. These results demonstrate that the indispensability of dietary ARG is not only related to optimized protein utilization for growth but also its supplementation to fish diets may significantly impact several aspects of the immune system, including phagocyte function and thus improve overall fish health. 相似文献
38.
Fish have limited ability in endogenous biosynthesis of arginine. Arginine is an indispensable amino acid for fish, and the arginine requirement varies with fish species and fish size. Recent studies on fish have demonstrated that arginine influences nutrient metabolism, stimulates insulin release, is involved in nonspecific immune responses and antioxidant responses, and elevates disease resistance. Specifically, arginine can regulate energy homeostasis via modulating the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway, and also regulate protein synthesis via activating the target of rapamycin (TOR) signaling pathway. The present article reviews pertinent knowledge of arginine in fish, including dietary quantitative requirements, endogenous anabolism and catabolism, regulation of the endocrine and metabolic systems, and immune-regulatory functions under pathogenic challenge. Our findings showed that further data about the distribution of arginine after intake into specific cells, its sub-cellular sensor to initiate downstream signaling pathways, and its effects on fish mucosal immunity, especially the adaptive immune response against pathogenic infection in different species, are urgently needed. 相似文献
39.
40.
R. J. Haynes 《Biology and Fertility of Soils》1999,30(3):210-216
The effects of 5 years of continuous grass/clover (Cont grass/clover) or grass (Cont grass) pasture or 5 years of annual
grass under conventional (Ann grass CT) or zero tillage (Ann grass ZT) were compared with that of 5 years of continuous barley
(LT arable) on a site which had previously been under arable crops for 11 years. For added comparison, a long-term grass/clover
pasture site (LT past) nearby was also sampled. Soil organic C (Corg) content followed the order LT arable=Ann grass CT<Ann grass ZT<Cont grass=Cont grass/clover<LTpast. Trends with treatment
for microbial biomass C (Cmic), basal respiration, flourescein diacetate (FDA) hydrolytic activity, arginine ammonification rate and the activities of
dehydrogenase, protease, histidase, acid phosphatase and arylsulphatase enzymes were broadly similar to those for Corg. For Cmic, FDA hydrolysis, arginine ammonification and the activities of histidase, acid phosphatase and arylsulphatase, the percentage
increase caused by 5 years of continuous pasture (in comparison with LT arable) was 100–180%, which was considerably greater
than that for organic C (i.e. 60%). The microbial metabolic quotient (qCO2) was higher for the two treatments which were mouldboard ploughed annually (LT arable and Ann grass CT) than for the undisturbed
sites. At the undisturbed sites, Corg declined markedly with depth (0–15 cm) and there was a similar stratification in the size and activity of Cmic and enzyme activity. The microbial quotient (Cmic/Corg) declined with depth whilst qCO2 tended to increase, reflecting a decrease in the proportion of readily available substrate with depth.
Received: 7 July 1998 相似文献