Effect of tri-o-cresyl phosphate and methamidophos on Ca uptake by brain synaptosomes in hens

The effect of tri-o-cresyl phosphate (TOCP) and methamidophos (MET) on potassium-stimulated ⁴⁵Ca uptake by brain synaptosomes in hens was studied. An in vivo test showed that TOCP increased potassium-stimulated calcium uptake 2 h after its administration, but that verapamil suppressed the enhancement of this calcium uptake. An in vitro test showed that lower concentrations of TOCP stimulated calcium uptake by synaptosomes, but that higher concentrations inhibited the uptake. In contrast, all tested concentrations of MET obviously inhibited calcium uptake; however, since calcium uptake was decreased by the administration of verapamil plus either TOCP or MET, the mechanism by which TOCP affects the voltage-operated calcium channel may be different from that of MET. The disruption of calcium homeostasis may be involved in organophosphate-induced delayed neurotoxicity (OPIDN). Calcium channel blocker may ameliorate OPIDN by maintaining calcium homeostasis in nerve cells.     

Effects of three kinds of calcium activator on the proliferation of cultured vascular smooth muscle cells in rats

AIM: To investigate the effects of intracellular free calcium ([Ca²⁺]i) from different resources on the proliferation mediated by mitogen activated protein kinase (MAPK) in vascular smooth muscle cells (VSMCs). METHODS: Cultured VSMCs were used in all experiments. Calcium influx was stimulated by angiotension Ⅱ(Ang Ⅱ). The release of intracellular calcium stores was induced by inositol trisphosphate (IP₃) and ryanodine (RY). MAPK activity was measured by [γ-³²P]-ATP incorporation MAPK protein expression by western blot, VSMCs proliferation by [³H]-Leucine ([³H]-Leu) and [³H]-Thymidine ([³H]-TdR) incorporation. RESULTS: Compared to the control VSMCs, Ang Ⅱ, IP₃ and RY significantly increased [Ca²⁺]i concentration activity of MAPK and its protein content in VSMCs. The promotion of [³H]-Leu and [³H]-TdR incorporation in VSMCs was also observed (P<0.01). CONCLUSION: The study indicated that calcium activator-induced increase in the activity and protein content of MAPK was involved in the proliferation of VSMCs, which was closely related to the [Ca²⁺]i concentration but independent to its origin.     

Effect of compound salvae-dropping-pill on intracellular free calcium concentration of cultured rat myocardial cells in case of hypoxia and reoxygenation

AIM:To examine the effect of compound salvae-dropping-pill (CSDP) on intracellular free calcium in cultured rat myocardial cells subjected to hypoxia and reoxygenation.METHODS:The Fluo- 3/AM was applied to probe intracellular calcium concentration and the fluorescent intensity was detected using laser confocal microscopy technique.RESULTS:Fluorescent intensity in hypoxia plus CSDP group was significantly lower (1 217.78±312.07) than that of hypoxia group (1 509±508.48), and the Fluorescent intensity of hypoxia/reoxygenation plus CSDP group was also markedly lower (1 567.91±577.61) than that of hypoxia/reoxygenation group (1 617.60±477.53).CONCLUSION:The cultured rat myocardial cells could be effectively protected by administration of CSDP in case of hypoxia and reoxygenation through decreasing the intracellular calcium concentration.     

日粮钙、锌对京白鸡增重、体况及组织矿物元素含量的影响

本研究选用72只6周龄京白鸡,随机分为A、B、C、D、E和F六组,分别饲喂钙、锌水平不同的日粮(各组锌、钙分别为:21.5ppm,0.95％;21.5ppm,1.95％;21.5ppm,2.95％;49ppm,0.95％;49ppm,1.95％;49ppm,2.95％),进行为期30天的饲养试验。试验中观察增重和临床变化;饲养结束时,取全血、羽毛、胫骨、肝和肾等组织的样本,测定其锌、钙、铁、铜、锰等元素的含量。试验结果是,D组增重和发育良好;A组稍次于D组;其他各组出现程度不同的临床症状,并且这些组所测组织锌含量明显低于D、A组,且其羽毛铁、骨铜、羽毛锰含量明显升高,而羽毛铜、肾铜及肾锰则显著降低。     

Effect of Seed Pre-sowing Hardening on Physiological Behaviour and Seed Yield of Berseem (Trifolium alexandrinum L.) Crop

A field experiment was conducted at Central Research Farm, Indian Grassland and Fodder Research Institute, Jhansi to study the effect of seed pre-sowing hardening on seed emergence, physiological behaviour — and seed yield of berseem ( Trifolium alexandrinum L. Var. S-99-1) crop. For this purpose, seed pre-sowing hardening were made by soaking of seeds in tap water for 24 and 36 hours separately and later dried back to their original weight or left undried. These seeds were sown at two depths (5 and 3 cm) and judged against control (no soaking). Results demonstrated that augmented effect of seed hardening on seed emergence and physiological process responsible for seed yield was recorded in descending order of harden seeds (of 24 hours soaking) > non harden seeds (of 24 hours soaking) > harden seeds (of 36 hours soaking); while non-harden seeds of 36 hours soaking adversely affect the plant growth because of leaching of sugar during excess soaking — an element for reduced seed vigour potential. Seed hardening system developed the strength of seed emergence on account of efficient catabolic process releasing high water soluble sugars needed for efficient germination process. Further this process augmented the absorption mechanism of mineral nutrients (particularly phosphorus and nitrogen with marginal variation in calcium) was quite evident at bloom stage — indicating a high metabolic activity during this period. Performance of seed hardening was effective at 5 cm deep sowing.     

施用"氰铵化钙"对紫花苜蓿生长效应的试验

对来自国内外的4个紫花苜蓿Medicago sativa品种进行了“氰铵化钙”苗前除草剂的使用效果试验,主要对杂草的抑制率和增产效果进行了测定。结果表明,施用“氰铵化钙”对杂草有显著的抑制作用,尤其是对禾本科杂草抑制率均达69.7%以上;对各品种的增产效果也很显著,增产幅度达10.2%~28.2%,品种中以飞马的增产效果最明显。初步分析,“氰铵化钙”作为苗前除草剂用于苜蓿草生产,对苜蓿还有增产效果,因此值得推广应用。     

稀土对山定子、红富士苹果树体与果实钙含量影响的研究

水培试验表明,稀土有平衡树体钙素营养的作用,在钙浓度低时,稀土能促进果树对钙的吸收,在钙浓度高时,可在一定程度上抑制果树对钙的吸收。田间喷钙可促进果树对氮、钙、锌的吸收,并增加果实中钙的浓度。稀土、钙混合液浸果可使果实中钙浓度增加0.165%,保鲜率比对照增加26%。     

白藜芦醇对HA-VSMC细胞膜电位和钙离子的影响

[目的]研究白藜芦醇对人主动脉血管平滑肌细胞(T/G HA-VSMC)膜电位和游离钙浓度的影响。[方法]用荧光染料DiBAC4(3)和Fluo-3-AM分别标记细胞,在流式细胞仪上分别测定细胞膜电位及胞内游离钙浓度的变化。[结果]给予Res后,HA-VSMC膜电位去极化,胞内游离钙浓度升高。[结论]Res可去极化HA-VSMC细胞膜电位,促进钙内流。     

Effects of Dryk1A,ASF and alternative splicing of CaMKⅡδ on myocardial hypertrophy in renovascular hypertensive rats

AIM: To investigate the role of dual-specificity tyrosine phosporylation-regulated kinase 1A (Dyrk1A)-alternative splicing factor (ASF)-calcium/calmodulin-dependent protein kinase Ⅱδ (CaMK Ⅱδ) pathway in the progression of myocardial hypertrophy in renovascular hypertensive rats. METHODS: The renovascular hypertension was induced by two-kidney one-clip (2K1C) method. The changes of blood pressure and myocardial hypertrophy were measured. The techniques of RT-PCR and Western blotting were used to detect CaMKⅡδ alternative splicing and the protein expression of Dyrk1A and ASF, respectively. RESULTS: Eight weeks after operation, systolic blood pressure (SBP) and diastolic blood pressure (DBP) in 2K1C rats increased (P<0.05). The increases in left ventricular weight (LVW), the ratio of LVW to body weight (BW) and the area of myocardial cells indicated that the hypertensive rats developed significant cardiac hypertrophy. The protein expression of Dyrk1A and mRNA expression of CaMKⅡδA and δB were significantly increased, while the protein expression of ASF and mRNA expression of CaMKⅡδC were decreased compared with sham-operated control rats (P<0.05). Treatment with Dryk1A inhibitor epigallocatechin gallate (EGCG) or harmine effectively attenuated cardiac hypertrophy and reversed the changes in the protein expression of Dyrk1A, ASF and alternative splicing of CaMKⅡδ (all P<0.05). CONCLUSION: Dyrk1A-ASF-CaMKⅡδ pathway plays a role in the development of myocardial hypertrophy in renovascular hypertensive rats.     

钙对茉莉酸甲酯诱导番茄抗灰霉病及防御酶活性的调控作用

以番茄品种L402幼苗为试材,通过外源施钙和缺钙处理,探讨钙对茉莉酸甲酯（MeJA）诱导番茄抗灰霉病的作用及其生理机制。结果表明：（1）外源MeJA显著诱导番茄抗灰霉病|外源钙离子进一步增强MeJA诱导的抗病程度|而钙螯合剂EGTA和质膜钙通道抑制剂LaCl3则不同程度抑制MeJA诱导番茄的抗病性。（2）MeJA单独处理后2～5 d内PAL、PPO和POD活性显著高于对照,外源钙离子进一步增强MeJA诱导的上述防御酶活性,两种缺钙处理则不同程度降低防御酶活性。（3）外源施钙及不同缺钙处理,对MeJA诱导的CAT和SOD活性没有规律性影响。由此认为,钙增强MeJA诱导番茄抗灰霉病的程度,可能与其对MeJA诱导番茄叶片中PAL、PPO和POD等防御酶活性的调控有关。