BACKGROUND & AIMS: Rabbits predominantly rearrange the most 3'VH gene (VH1); thus combinatorial diversity is very limited. In man and mouse, the most 3'DH gene, DQ52, is preferentially rearranged early in B-cell development. To test whether this preference for rearranging a DH gene segment based on 3' end proximity exists in rabbit, we cloned and sequenced the rabbit DQ52 gene. The 11 base pair coding region sequence is identical to a published mouse DQ52, and 81.8% similar to the human sequence. It is localized approximately 805 bp upstream of the JH1 gene. However, the 3' recombination signal sequence has an atypical nonamer. We prepared mRNA from 15- to 28-day fetal rabbits and amplified expressed VDJ sequences of mu mRNA by RT-PCR. The PCR products with VDJ rearrangements were cloned and sequenced. As expected, 44 of 45 VDJ sequences reflected use of the 3' VH1a2 gene, but the DQ52 gene was utilized very infrequently, if at all. We found only one VDJ sequence from 28-day fetal liver B-cells with 8 bp that matched the germline DQ52 sequence. Instead of expressing DQ52, another DH gene, Df was frequently expressed. We cloned the genomic Df gene and localized it about 32 kb upstream of the JH region. Thus, in contrast to man and mouse, rabbits preferentially express a DH gene located in the middle of the DH region early in B cell ontogeny. This may correlate with more frequent initial rearrangement of VH to DH in rabbit B cells.

背景与目标： 兔子主要重排最3'VH基因 (VH1); 因此组合多样性非常有限。在人和小鼠中，最3'DH基因DQ52在b细胞发育的早期优先重排。为了测试兔子中是否存在基于3' 末端邻近度重新排列DH基因片段的偏好，我们克隆并测序了兔子DQ52基因。11个碱基对编码区序列与已发表的小鼠DQ52相同，并且81.8% 类似于人序列。它位于JH1基因上游约805 bp。但是，3' 重组信号序列具有非典型的非amer。我们从15至28天的胎兔中制备了mRNA，并通过rt-pcr扩增了mu mRNA的VDJ表达序列。克隆并测序具有VDJ重排的PCR产物。正如预期的那样，在45个VDJ序列中，有44个反映了3'vh1a2基因的使用，但是DQ52基因很少被使用 (如果有的话)。我们从28天的胎儿肝b细胞中发现只有一个VDJ序列，其8 bp与种系DQ52序列匹配。Df不表达另一个DH基因DQ52，而是经常表达。我们克隆了基因组Df基因，并将其定位在JH区域上游约32 kb。因此，与人和小鼠相比，兔子在b细胞个体发育早期优先表达位于DH区域中部的DH基因。这可能与兔b细胞中VH到DH的更频繁的初始重排有关。

BACKGROUND & AIMS: :Cyclic AMP levels in rabbit carotid bodies incubated under control conditions, 100% O2- or 95% O2/5% CO2- equilibrated medium, are close to 1 pmol/mg wet tissue (range 0.4-2.43 pmol/mg). Isobutylmethylxanthine (0.5 mM) increases cyclic AMP levels by a factor of 14 and 8 in HEPES- and CO2/CH3O(-)-buffered medium, respectively. Forskolin (0.5-10 microM) applied during 30 min increases cyclic AMP levels in a dose-dependent manner. Incubation of carotid bodies at low O2 tensions resulted in an elevation of cyclic AMP levels both in the absence and in the presence of isobutymethylxanthine. In the latter conditions cyclic AMP increase was maximum at an O2 tension of 46 mm Hg and tended to decrease at extremely low PO2. In isobutylmethylxanthine-containing Ca2(+)-free medium, cyclic AMP increased linearly with decreasing PO2 from 66 to 13 mm Hg; the absolute cyclic AMP levels attained in Ca2(+)-free medium were smaller than those observed in Ca2(+)-containing medium at any PO2. The differences between Ca2(+)-free and Ca2(+)-containing media appear to be due to the action of released neurotransmitters in the latter conditions, because dopamine and norepinephrine, which are known to be released by hypoxia in a Ca2(+)-dependent manner, increase cyclic AMP in the carotid body. Low pH/high PCO2 and high [K+]e increase cyclic AMP levels only in Ca2(+)-containing medium. Forskolin potentiates the release of catecholamines induced by low PO2. These results suggest that cyclic AMP plays an important role in the modulation of the chemoreception process.

背景与目标： : 在100% O2-或95% O2/5% CO2平衡的培养基的对照条件下孵育的兔颈动脉体中的循环AMP水平接近1 pmol/mg湿组织 (范围0.4-2.43 pmol/mg)。在HEPES-和CO2/CH3O(-) 缓冲介质中，异丁基甲基黄嘌呤 (0.5 mM) 使环状AMP水平分别增加14和8倍。在30分钟期间施加的福司可林 (0.5-10微米) 以剂量依赖性方式增加循环AMP水平。在低O2张力下孵育颈动脉体会在不存在和存在异丁甲基黄嘌呤的情况下导致环状AMP水平升高。在后一种条件下，循环AMP的增加在46毫米Hg的O2张力下最大，并在极低的po2下趋于降低。在含异丁基甲基黄嘌呤的无Ca2 () 的培养基中，环状AMP随着PO2从66 Hg降低到13毫米Hg而线性增加; 在无Ca2 () 的培养基中获得的绝对环状AMP水平小于在任何PO2下在含Ca2 () 的培养基中观察到的绝对环状AMP水平。不含Ca2(+) 和含Ca2(+) 的培养基之间的差异似乎是由于在后一种情况下释放的神经递质的作用，因为多巴胺和去甲肾上腺素，已知它们是由缺氧以Ca2(+) 依赖性方式释放的，增加颈动脉体中的循环AMP。低pH/高PCO2和高 [K] e仅在含Ca2 () 的培养基中增加循环AMP水平。Forskolin可增强低po2诱导的儿茶酚胺的释放。这些结果表明，循环AMP在化学感受过程的调制中起着重要作用。

BACKGROUND & AIMS: :The effect of ketamine on myocardial contractile force was examined in rabbit papillary muscles in order to determine the underlying mechanism of action of the anesthetic. Ketamine HCl (20 and 40 mg/L) inhibited rested-state contractions that are dependent on the transsarcolemmal influx of Ca2+ for activation and reduced the upstroke velocity of the slow action potential, which reflects Ca2+ influx through the slow Ca2+ channel. On the other hand, ketamine had a relatively small effect on potentiated-state contractions and no effect on rapid cooling induced contractures, both of which are activated by the release of Ca2+ stored in the sarcoplasmic reticulum. These results suggest that ketamine inhibition of transsarcolemmal Ca2+ influx plays a major role in the negative inotropic action of the anesthetic.

背景与目标： : 在兔乳头肌中检查了氯胺酮对心肌收缩力的影响，以确定麻醉剂作用的潜在机制。氯胺酮HCl (20和40 mg/L) 抑制了依赖于Ca2的跨膜内流激活的静息状态收缩，并降低了慢动作电位的上行速度，这反映了通过慢速Ca2通道的Ca2内流。另一方面，氯胺酮对增强态收缩的影响相对较小，而对快速冷却引起的挛缩没有影响，这两者均被存储在肌浆网中的Ca2释放激活。这些结果表明，氯胺酮对跨肌膜Ca2内流的抑制在麻醉剂的负性肌力作用中起主要作用。

BACKGROUND & AIMS: :1. Intravital microscopy of rabbit tenuissimus muscle microvasculature was used for in vivo studies of the role of endogenous nitric oxide (NO) in local vascular control. Derivatives of arginine were applied topically in order to modulate the formation of NO from L-arginine. 2. L-NG-monomethylarginine (L-NMMA) (10-100 microM), but not D-NG-monomethylarginine (D-NMMA), dose-dependently reduced microvascular diameters. The vasoconstriction induced by L-NMMA (100 microM) was prevented by pretreatment with L-arginine (1 mM) but not with D-arginine (1 mM). Intravenous infusions of L-arginine (300 mg kg-1) reversed the effect of L-NMMA (100 microM). L-Arginine or D-arginine applied topically at 1 mM per se had no effect on microvascular diameters. 3. Vasodilatation by acetylcholine (0.03-3 microM) was significantly inhibited by L-NMMA (100 microM), whereas vasodilatation by adenosine (0.1-100 microM) or sodium nitroprusside (100 nM) was not affected. 4. The hyperaemic response after tenuissimus muscle contractions induced by motor nerve stimulation was unaffected by the presence of L-NMMA (100 microM). 5. Aggregates of platelets and white blood cells were seen in venules during superfusion with L-NMMA (100 microM), but not with D-NMMA (100 microM). 6. Our results suggest that endogenous NO formed from L-arginine is a modulator of microvascular tone and platelet and white cell-vessel wall interaction in vivo. Nitric oxide does not, however, appear to play a role in the mediation of functional hyperaemia in this tissue.

背景与目标： : 1。兔腱鞘肌微血管的活体显微镜用于体内研究内源性一氧化氮 (NO) 在局部血管控制中的作用。局部应用精氨酸衍生物，以调节L-精氨酸中NO的形成。2. L-NG-单甲基精氨酸 (l-nmma) (10-100微米)，但不是D-NG-单甲基精氨酸 (d-nmma)，剂量依赖性地减小微血管直径。通过用L-精氨酸 (1毫米) 而不是用D-精氨酸 (1毫米) 预处理来防止L-NMMA (100 microM) 诱导的血管收缩。静脉输注L-精氨酸 (300 mg kg-1) 可逆转L-NMMA (100 microM) 的作用。L-精氨酸或D-精氨酸以1毫米本身局部施用对微血管直径没有影响。3.乙酰胆碱 (0.03-3 microM) 的血管扩张被L-NMMA (100 microM) 显着抑制，而腺苷 (0.1-100 microM) 或硝普钠 (100 nM) 的血管扩张不受影响。4.运动神经刺激引起的肌腱收缩后的充血反应不受L-NMMA (100 microM) 的影响。5.在与L-NMMA (100微米) 的融合过程中，在小静脉中观察到血小板和白细胞的聚集，而与D-NMMA (100微米) 则没有。6.我们的结果表明，由L-精氨酸形成的内源性NO是体内微血管张力和血小板与白细胞-血管壁相互作用的调节剂。然而，一氧化氮似乎在该组织中功能性充血的调解中不起作用。

BACKGROUND & AIMS: :The 5' cap and 3' poly(A) tail of eukaryotic mRNAs cooperate to synergistically stimulate translation initiation in vivo. We recently described mammalian cytoplasmic extracts which, following ultracentrifugation to partially deplete them of ribosomes and associated initiation factors, reproduce cap-poly(A) synergy in vitro. Using these systems, we demonstrate that synergy requires interaction between the poly(A)-binding protein (PABP) and the eukaryotic initiation factor (eIF) 4F holoenzyme complex, which recognises the 5' cap. Here we further characterise the requirements and constraints of cap-poly(A) synergy in reticulocyte lysates by evaluating the effects of different parameters on synergy. The extent of extract depletion and the amounts of different initiation factors in depleted extracts were examined, as well as the effects of varying the concentrations of KCl, MgCl(2) and programming mRNA and of adding a cap analogue. The results presented demonstrate that maximal cap-poly(A) synergy requires: (i) limiting concentrations of ribosome-associated initiation factors; (ii) precise ratios of mRNA to translation machinery (low concentrations of ribosome-associated initiation factors and low, non-saturating mRNA concentrations); (iii) physiological concentrations of added KCl and MgCl(2). Additionally, we show that the eIF4G-PABP interaction on mRNAs which are capped and polyadenylated significantly increases the affinity of eIF4E for the 5' cap.

背景与目标： : 真核mrna的5' 帽和3' 聚 (A) 尾协同刺激体内翻译起始。我们最近描述了哺乳动物的细胞质提取物，在超速离心以部分耗尽它们的核糖体和相关的起始因子后，它们在体外复制了cap-poly(A) 协同作用。使用这些系统，我们证明协同作用需要聚 (A) 结合蛋白 (PABP) 与真核起始因子 (eIF) 4F全酶复合物之间的相互作用，该复合物识别5' 帽。在这里，我们通过评估不同参数对协同作用的影响，进一步表征了网织红细胞裂解物中cap-poly(A) 协同作用的要求和约束。检查了提取物消耗的程度和消耗的提取物中不同起始因子的量，以及改变KCl，MgCl(2) 和编程mRNA的浓度以及添加cap类似物的影响。提出的结果表明，最大的cap-poly(A) 协同作用需要 :( i) 限制核糖体相关起始因子的浓度; (ii) mRNA与翻译机制的精确比率 (低浓度的核糖体相关起始因子和低的非饱和mRNA浓度); (iii) 添加的KCl和MgCl的生理浓度 (2)。此外，我们显示在被封端和多聚腺苷酸化的mrna上的eIF4G-PABP相互作用显着增加了eIF4E对5' 帽的亲和力。

BACKGROUND & AIMS: The hazards of using optic nerve (as opposed to optic tract and more distal components of the optic system) to study axonal transport were highlighted by observing the fate of [14C]serine and [3H]glycerol injected into the rabbit eye. Despite prior blockage of axonal transport with colchicine, appreciable radioactivity rapidly appeared in the optic nerve adjacent to the injected eye. Radioactivity decreased exponentially along the entire optic chiasm. Counts were distributed among the lipid, protein, and acid-soluble fractions. Separation of optic nerve lipids revealed appreciable labeling of most lipid classes including those characteristic of myelin; a markedly different labeling pattern was observed for axonally transported lipids. The data are consistent with a mechanism involving extra-axonal diffusion of precursor into the surrounding glia followed by incorporation into lipids and proteins of those cells and ultimately myelin. The phenomenon is discussed in relation to possible errors that were made in interpreting earlier experiments.

背景与目标： 通过观察注射到兔眼中的 [14C] 丝氨酸和 [3H] 甘油的命运，突出了使用视神经 (相对于视神经系统和更多视神经系统的远端成分) 来研究轴突运输的危害。尽管先前用秋水仙碱阻断了轴突运输，明显的放射性迅速出现在与注射的眼睛相邻的视神经中。放射性沿整个视交叉呈指数下降。计数分布在脂质、蛋白质和酸溶性部分中。视神经脂质的分离揭示了大多数脂质类别的明显标记，包括髓磷脂的特征; 对于轴突运输的脂质观察到明显不同的标记模式。数据与涉及前体轴突外扩散到周围神经胶质的机制一致，然后掺入到这些细胞的脂质和蛋白质以及最终髓磷脂中。讨论了与解释早期实验中可能出现的错误有关的现象。

BACKGROUND & AIMS: :End-expiratory occlusion test (EEOT) has been proposed as a preload responsiveness test that overcomes several limitations of pulse pressure (PPV) and stroke volume (SVV) variations. We compared the ability of EEOT versus SVV and PPV to predict fluid responsiveness during the increase of the vasomotor tone in a rabbit model of hemorrhage. Ten rabbits were anesthetized, paralyzed, and mechanically ventilated during basal load (BL), after progressive blood withdrawal (BW), and after volume replacement. Other two sets of data were obtained during vasomotor increase by phenylephrine (PHE) infusion in BL and BW. We estimated the change of stroke volume (∆SVEEOT) and aortic flow (∆AoFEEOT) during the EEOT. PPV and SVV were obtained by the variation of beat-to-beat PP and SV, respectively. Baseline PPV, SVV, ∆SVEEOT, and ∆AoFEEOT increased significantly after BW, with a decrease of aortic flow (P < 0.05). PHE induced a significant decrease of PPV and SVV, but without affecting ∆SVEEOT, and ∆AoFEEOT. We conclude that ∆SV and ∆AoF during EEOT kept the ability to predict fluid responsiveness during PHE infusion in a rabbit hemorrhage model. This result may suggest the advantage of EEOT with respect to SVV and PPV in predicting fluid responsiveness during vasomotor tone increase.

背景与目标： : 呼气末阻塞测试 (EEOT) 已被提议作为一种预载响应性测试，克服了脉压 (PPV) 和中风量 (SVV) 变化的几个限制。我们比较了EEOT与SVV和PPV在兔出血模型中血管舒缩张力增加期间预测液体反应性的能力。在基础负荷 (BL)，进行性抽血 (BW) 和容量置换后，将十只兔子麻醉，瘫痪和机械通气。在BL和BW中输注去氧肾上腺素 (PHE) 增加血管舒缩期间获得了其他两组数据。我们估计了EEOT期间中风量 (∆ sveeot) 和主动脉血流 (∆ aofeeot) 的变化。PPV和SVV分别通过节拍PP和SV的变化获得。基线PPV、SVV、 ∆ sveeot和 ∆ aofeeot在BW后显著增加，主动脉血流减少 (p  <  0.05)。PHE引起PPV和SVV的显着降低，但不影响 ∆ sveeot和 ∆ aofeeot。我们得出的结论是，EEOT期间的 ∆ sv和 ∆ aof在兔出血模型中保持了预测PHE输注期间液体反应性的能力。该结果可能表明EEOT相对于SVV和PPV在预测血管舒缩张力增加期间的液体反应性方面具有优势。

BACKGROUND & AIMS: :Anandamide (AEA) presents the four double bonds in the cis configuration, deriving from the arachidonic acid moiety. In the context of an antisense strategy based on the double bond configuration, all-trans AEA (t-AEA) was synthesized in high yield starting from all-trans methyl arachidonate and ethanolamine in the presence of KCN. t-AEA was assayed on rabbit platelet aggregation, obtaining effect only at high concentrations (>10(-4) M) after an also concentration-dependent lag phase. At lower concentrations it inhibited PAF-induced rabbit platelet aggregation with an IC(50)=4.6 x 10(-6) M. In contrast to anandamide, the activation of platelets was not due to the conversion of t-AEA to trans arachidonic acid, as ascertained by negative results with FAAH inhibitors. However, t-AEA was found to be a substrate for fatty acid amide hydrolase (FAAH), the enzyme that cleaves anandamide and regulates in vivo the magnitude and duration of the signaling induced by this lipid messenger.

背景与目标： : Anandamide (AEA) 在顺式构型中呈现四个双键，源自花生四烯酸部分。在基于双键构型的反义策略的背景下，在KCN存在下，从全反式甲基花生四烯酸和乙醇胺开始，高产率合成了全反式AEA (t-aea)。t-AEA对兔血小板聚集进行了测定，仅在浓度依赖性滞后阶段后才在高浓度 (>10(-4) M) 下获得效果。在较低的浓度下，它以IC(50)= 4.6 × 10(-6) M抑制PAF诱导的兔血小板聚集。与anandamide相反，血小板的活化不是由于t-AEA转化为反式花生四烯酸，这是由FAAH抑制剂的阴性结果确定的。然而，发现t-AEA是脂肪酸酰胺水解酶 (FAAH) 的底物，该酶可裂解anandamide并在体内调节由该脂质信使诱导的信号传导的幅度和持续时间。

BACKGROUND & AIMS: UNLABELLED:Several lines of evidence have demonstrated that C-reactive protein (CRP) is associated with oxidative stress; however, the precise co-localization between CRP and oxidative stress markers in atherosclerotic lesions is not fully established. In this study, we focused on two oxidative stress markers, dityrosine (DY) and N(epsilon)-(hexanoyl)lysine (HEL), which had not previously been investigated in relation to CRP in atherosclerotic lesions. AIM:We investigated the production and localization of DY, HEL, and CRP in early-stage and moderately progressed fatty lesions of cholesterol-fed rabbits by immunohistochemistry using specific monoclonal antibodies to examine the co-localization between CRP and oxidative stress in atherosclerotic lesions. METHODS:Rabbit atherosclerotic specimens were obtained from New Zealand White rabbits fed a diet containing 1.0% cholesterol for 12 weeks. All specimens were fixed in formalin for histological examinations. RESULTS:CRP-positive cells in rabbit early-stage and moderately progressed fatty lesions were detected mostly in the macrophage-derived foam cell-rich areas. Both DY and HEL were also detected in foam cell-rich areas in both lesions, where they were primarily co-localized with CRP-positive cells. CONCLUSION:Our results suggest that the generation of oxidative stress markers, DY and HEL, may be mediated by CRP in atherosclerotic lesions, and that CRP may be associated with oxidative stress in rabbit atherosclerotic lesions.

背景与目标：

BACKGROUND & AIMS: :Cell-based tendon therapies with tenocytes as a cell source need effective tenocyte in vitro expansion before application for tendinopathies and tendon injuries. Supplementation of tenocyte culture with biomolecules that can boost proliferation and matrix synthesis is one viable option for supporting cell expansion. In this in vitro study, the impacts of ascorbic acid or PDGF-BB supplementation on rabbit Achilles tenocyte culture were studied. Namely, cell proliferation, changes in gene expression of several ECM and tendon markers (collagen I, collagen III, fibronectin, aggrecan, biglycan, decorin, ki67, tenascin-C, tenomodulin, Mohawk, α-SMA, MMP-2, MMP-9, TIMP1, and TIMP2) and ECM deposition (collagen I and fibronectin) were assessed. Ascorbic acid and PDGF-BB enhanced tenocyte proliferation, while ascorbic acid significantly accelerated the deposition of collagen I. Both biomolecules led to different changes in the gene expression profile of the cultured tenocytes, where upregulation of collagen I, Mohawk, decorin, MMP-2, and TIMP-2 was observed with ascorbic acid, while these markers were downregulated by PDGF-BB supplementation. Vice versa, there was an upregulation of fibronectin, biglycan and tenascin-C by PDGF-BB supplementation, while ascorbic acid led to a downregulation of these markers. However, both biomolecules are promising candidates for improving and accelerating the in vitro expansion of tenocytes, which is vital for various tendon tissue engineering approaches or cell-based tendon therapy.

背景与目标： : 以肌腱细胞为细胞来源的基于细胞的肌腱疗法在用于肌腱病和肌腱损伤之前需要有效的肌腱细胞体外扩增。用可以促进增殖和基质合成的生物分子补充tenocyte培养物是支持细胞扩增的一种可行选择。在这项体外研究中，研究了抗坏血酸或pdgf-bb补充剂对兔跟腱细胞培养的影响。即细胞增殖，几种ECM和肌腱标记物 (胶原蛋白I，胶原蛋白III，纤连蛋白，聚集蛋白聚糖，双聚糖，decorin，ki67，tenascin-C，tenomodulin，Mohawk，α-SMA，MMP-2，MMP-9，TIMP1，和TIMP2) 和ECM沉积 (胶原蛋白I和纤连蛋白) 进行了评估。抗坏血酸和pdgf-bb增强了腱细胞的增殖，而抗坏血酸则显着加速了胶原蛋白I的沉积。两种生物分子导致培养的肌腱细胞的基因表达谱的不同变化，其中抗坏血酸观察到胶原蛋白I，莫霍克，decorin，MMP-2和TIMP-2的上调，而这些标记物通过补充pdgf-bb下调。反之亦然，通过补充pdgf-bb，纤连蛋白，双聚糖和腱生蛋白C上调，而抗坏血酸导致这些标记物下调。然而，这两种生物分子都是改善和加速肌腱细胞体外扩增的有希望的候选者，这对于各种肌腱组织工程方法或基于细胞的肌腱治疗至关重要。

BACKGROUND & AIMS: :cDNAs for hyaluronic acid synthases (HAS2 and HAS3) were cloned from a cDNA library of cultured rabbit synovial membrane cells. The cDNA encoding the open reading frame of rabbit HAS2 and HAS3 was 1659 nucleotides in length with a predicted molecular mass of about 63 kDa. The amino acid sequence showed that the rabbit HAS2 was 98.7 and 98.4%, and HAS3 was 98.2 and 97.5% identical with human and mouse forms of the proteins, respectively. The predicted sequences for hyaluronic acid (HA) binding motifs and the catalytic domains related to beta 1-4 and beta 1-3 linkages, essential for HA synthesis, were almost conserved in both rabbit HAS2 and HAS3, similarly to human and mouse HASs. RT-PCR analysis and in situ hybridization revealed that the mRNA of HAS2 was highly expressed in the synovial membrane and articular cartilage, whereas the expression of HAS3 mRNA was slightest in these tissues. Thus, it is demonstrated that rabbit HASs are highly conserved in sequence content as compared to the human and mouse homologues described previously, and that HAS2 is predominantly expressed in the synovial membrane and articular cartilage, but HAS3 is not.

背景与目标： : 从培养的兔滑膜细胞的cDNA文库中克隆了透明质酸合酶 (HAS2和HAS3) 的cDNA。编码兔HAS2和HAS3的开放阅读框的cDNA长度为1659个核苷酸，预测分子量约为63 kDa。氨基酸序列显示兔HAS2为98.7和98.4%，HAS3分别与人和小鼠形式的蛋白质98.2和97.5% 相同。透明质酸 (HA) 结合基序的预测序列以及与HA合成必不可少的 β1-4和 β1-3键相关的催化结构域，在兔HAS2和HAS3中几乎都是保守的，类似于人和小鼠HASs。Rt-pcr分析和原位杂交显示，HAS2的mRNA在滑膜和关节软骨中高表达，而HAS3 mRNA在这些组织中的表达最小。因此，已证明与先前描述的人和小鼠同源物相比，兔HASs的序列含量高度保守，并且HAS2主要在滑膜和关节软骨中表达，而HAS3则不表达。

BACKGROUND & AIMS: :Separation of fractions enriched in hypertrophic cells and proliferative cells has been achieved by density gradient centrifugation of cells from collagenase digests of rabbit epiphyseal cartilage. Concentrated suspensions of cells are centrifuged on a continuous Percoll density gradient. Hypertrophic cells remain in the upper part of the gradient and proliferative zone cells move to the lower regions. The resultant fractions show differences in mean cell diameter, alkaline phosphatase activity, morphology and synthetic activity in culture. Fractions rich in hypertrophic cells contain larger cells and more alkaline phosphatase activity than those enriched in proliferative cells. In culture the hypertrophic cells flatten as large irregular polygonal cells, whereas proliferative fractions form smaller spindle-shaped cells. In micromass culture hypertrophic fractions incorporate less 35S-sulphate and 14C-proline, and less tritiated thymidine than do proliferative fractions. These results suggest a general reduction in matrix and DNA synthesis with the attainment of the fully differentiated hypertrophic state, coincident with the expression of alkaline phosphatase activity and mineralisation of the cartilage matrix.

背景与目标： : 通过从兔epi骨软骨的胶原酶消化物中分离细胞的密度梯度离心，可以分离富含肥厚细胞和增殖细胞的级分。在连续的Percoll密度梯度上离心细胞的浓缩悬浮液。肥厚细胞保留在梯度的上部，增殖区细胞移动到下部区域。所得组分在培养物中显示出平均细胞直径，碱性磷酸酶活性，形态和合成活性的差异。富含肥厚细胞的组分比富含增殖细胞的组分含有更大的细胞和更多的碱性磷酸酶活性。在培养物中，肥厚细胞变平为大型不规则多边形细胞，而增殖部分形成较小的纺锤形细胞。在微质量培养中，肥厚级分与增殖级分相比，含有更少的35s硫酸盐和14c-脯氨酸，以及更少的tristiate胸苷。这些结果表明，随着完全分化的肥厚状态的实现，基质和DNA合成普遍减少，与碱性磷酸酶活性的表达和软骨基质的矿化相吻合。

BACKGROUND & AIMS: :The migration and spreading of the corneal epithelial cells adjacent to a wound is the first step in successful epithelial resurfacing. To understand the role of actin filaments and microtubules of the cytoskeletal system in the spreading of corneal epithelial cells, we plated rabbit corneal epithelial cells on a fibronectin matrix and studied the effects of cytochalasin B, which inhibits actin filaments assembly, and colchicine, which inhibits microtubules assembly, on the ability of individual cells to spread. Changes in the morphology of actin filaments and microtubules were also studied using immunofluorescent microscopy. The area of spread epithelial cells depended on the concentration of fibronectin used to coat the surface. In spread cells, stress fibers of actin filaments were evenly distributed throughout the cytoplasm, whereas microtubules were observed only at the perinuclear region. The presence of cytochalasin B during the cell attachment and spreading decreased the area of the spread cells more than did colchicine. However, once the epithelial cells were spread on a fibronectin matrix, cytochalasin B and colchicine each decreased the cell area only slightly, and to the same extent. These results indicate that formation of actin filaments is more important than formation of microtubules to the spreading of corneal epithelial cells.

背景与目标： : 与伤口相邻的角膜上皮细胞的迁移和扩散是成功进行上皮表面置换的第一步。为了了解肌动蛋白丝和细胞骨架系统微管在角膜上皮细胞扩散中的作用，我们将兔角膜上皮细胞铺在纤连蛋白基质上，研究了抑制肌动蛋白丝组装的细胞松弛素B和抑制微管组装的秋水仙碱的作用，单个细胞扩散的能力。还使用免疫荧光显微镜研究了肌动蛋白丝和微管形态的变化。扩散的上皮细胞的面积取决于用于覆盖表面的纤连蛋白的浓度。在扩散细胞中，肌动蛋白丝的应力纤维均匀分布在整个细胞质中，而微管仅在核周区域观察到。细胞附着和扩散过程中细胞松弛素B的存在比秋水仙碱减少了扩散细胞的面积。然而，一旦上皮细胞散布在纤连蛋白基质上，细胞松弛素B和秋水仙碱分别仅略微降低细胞面积，并达到相同程度。这些结果表明，肌动蛋白丝的形成比微管的形成对角膜上皮细胞的扩散更为重要。

BACKGROUND & AIMS: :To define the mechanism of regulation of the protein kinase that is activated in heme deficiency and that inhibits initiation of protein synthesis, we have isolated and purified the heme-reversible form of the protein kinase from rabbit reticulocytes. The inhibitory activity is found in a single band after polyacrylamide gel electrophoresis under nondenaturing conditions. It migrates as a 95,000-dalton polypeptide in 15% sodium dodecyl sulfate/polyacrylamide gels. This purified inhibitor becomes self-phosphorylated in the presence of ATP; the phosphorylated protein and the inhibitory activity copurify. The inhibitor produces characteristic biphasic kinetics of inhibition in reticulocyte lysates and phosphorylates the 38,000-dalton subunit of eukaryotic initiation factor 2 (eIF-2); the inhibition is reversed by added eIF-2. In contrast to the heme-irreversible inhibitor, this heme-reversible inhibitor is no longer inhibitory after incubation with 20 micron hemin. Incubation with hemin also inhibits self-phosphorylation. Preincubation of the heme-reversible inhibitor in the presence of ATP potentiates the inhibition of protein synthesis in the subsequent incubation, as does treatment with N-ethylmaleimide. Phosphorylation of the heme-reversible inhibitor and inhibition of protein synthesis in the lysate due to phosphorylation of eIF-2 appear to be related. These findings suggest that hemin acts directly on the heme-reversible inhibitor.

背景与目标： : 为了确定在血红素缺乏中被激活并抑制蛋白质合成起始的蛋白激酶的调节机制，我们从兔网织红细胞中分离并纯化了血红素可逆形式的蛋白激酶。在非变性条件下，聚丙烯酰胺凝胶电泳后，在单个条带中发现了抑制活性。它作为95,000-道尔顿多肽在15% 十二烷基硫酸钠/聚丙烯酰胺凝胶中迁移。在存在ATP的情况下，这种纯化的抑制剂会自我磷酸化; 磷酸化的蛋白质和抑制活性共聚。抑制剂在网织红细胞裂解物中产生抑制的特征性双相动力学，并使真核起始因子2 (eIF-2) 的38,000-道尔顿亚基磷酸化; 通过添加的eIF-2来逆转抑制。与血红素不可逆抑制剂相反，该血红素可逆抑制剂与20微米血红素孵育后不再具有抑制作用。与血红素一起孵育也抑制自磷酸化。与N-乙基马来酰亚胺处理一样，在ATP存在下对血红素可逆抑制剂的预孵育可增强随后孵育中蛋白质合成的抑制作用。血红素可逆抑制剂的磷酸化和由于eIF-2的磷酸化引起的裂解物中蛋白质合成的抑制似乎是相关的。这些发现表明，血红素直接作用于血红素可逆抑制剂。

BACKGROUND & AIMS: :In cumulative dose-response studies, strips from bladder neck of rabbit were significantly more sensitive to stimulation with noradrenaline, phenylephrine, and methoxamine than were strips from detrusor. There was no difference between the two regions in sensitivity to isoprenaline or carbachol. From the known characteristics of these agents, it seemed unlikely that metabolic destruction or uptake could account for the different sensitivities seen. Also, neither normetanephrine nor desmethylimipramine could alter significantly the potency of noradrenaline in either area of the bladder. It seems likely that the difference in sensitivity to alpha-adrenoceptor stimulation in the bladder neck and detrusor is due to factors at the receptor level.

背景与目标： : 在累积剂量反应研究中，兔膀胱颈条对去甲肾上腺素，去氧肾上腺素和甲氧明的刺激比逼尿肌条的刺激要敏感得多。两个区域对异丙肾上腺素或卡巴胆碱的敏感性没有差异。从这些药物的已知特征来看，代谢破坏或摄取似乎不太可能解释所看到的不同敏感性。而且，去甲肾上腺素和去甲基丙咪嗪都不能显着改变膀胱任一区域中去甲肾上腺素的效力。膀胱颈和逼尿肌对 α-肾上腺素受体刺激的敏感性差异似乎是由于受体水平的因素所致。