Post-molt processes of cuticle formation and calcification in the Japanese mitten crab <Emphasis Type="Italic">Eriocheir japonicus</Emphasis>

This study examines the following in the Japanese mitten crab: (1) the structure of the exoskeleton with special reference to its calcification; (2) the progression of post-molt cuticle formation and calcification. In the crab, the structure and calcification state of the exoskeleton at the molt and during the inter-molt stage were similar to those of other crustaceans. During the inter-molt, the exoskeleton consisted of four cuticle layers; the outermost epicuticle, the exocuticle, the endocuticle and the innermost membrane layer. Intense calcification was observed in the exo- and endocuticle. At the molt, the synthesis of the epi- and exocuticle was already complete, and the addition of the endocuticle began after the molt. Calcification of the exocuticle initiated soon after the molt, but there was a delay between endocuticle matrix synthesis and calcification. Histology showed that the process of calcification was similar to that in other crustaceans. However, calcium concentrations within the exoskeleton continued to increase and never reached the levels of the inter-molt stage at the end of the experiment. This suggests that the Japanese mitten crab is relatively slow to calcify compared to other crustaceans.     

Alterations of nitric oxide synthase in cardiac sarcoplasmic reticulum from rats with myocardial calcification

AIM: To study alterations of nitric oxide synthase (NOS) in cardiac sarcoplasmic reticulum from rats with myocardial calcification, and to explore the mechanism of inhibition of SR function in the rats with myocardial calcification. METHODS: Compared with control, myocardial calcium content in the 6 weeks increased by 408%（Ｐ＜0.01）, the NO production, NOS activity and NOS protein expression in the SR with myocardial calcification increased versus control（Ｐ＜0.01）.Myocardial calcium content was not alterations significantly, but the NOS/NO pathway in the SR was up-regulated slightly in the 2 weeks. RESULTS: Compared with control, myocardial calcium content in the 6 weeks increased by 408%(P＜0.01), the NO production, NOS activity and NOS protein expression in the SR with myocardial calcification increased versus control(P＜0.01).Myocardial calcium content was not alterations significantly, but the NOS/NO pathway in the SR was up-regulated slightly in the 2 weeks. CONCLUSION: The up-regulated NOS/NO system in the SR with myocardial calcification is the important mechanism of function inhibition of the SR.     

Effects of angiotensin-(1-7) on calcification in vascular smooth muscle cells and its signal transduction pathway

AIM: To clarify the effects of angiotensin-(1-7) on the calcification in rat vascular smooth muscle cells(VSMCs) and its signal transduction.METHODS: Calcification of cultured rat VSMCs was prepared by incubation of VSMCs with β-glycerophosphate.Calcification was confirmed by Von Kossa staining.The cells were treated with angiotensin-(1-7).The calcium content,alkaline phosphatases activity,osteocalcin and Cbfa1 mRNA expression were also measured.RESULTS: Angiotensin-(1-7) inhibited the increases of calcium content,alkaline phosphatases activity（P>0.05）,osteocalcin concentration and Cbfa1 mRNA expression in calcified VSMCs（P<0.05）,and the effects of angiotensin II on calcium content,alkaline phosphatases activity,osteocalcin concentration and Cbfa1 mRNA expression in calcified VSMCs were also inhibited （P<0.05）.Angiotensin-(1-7) increased cAMP concentration in calcified VSMCs（P<0.05）and selective PKA inhibitor blocked the effects of angiotensin-(1-7) on calcium content,alkaline phosphatases activity,osteocalcin concentration and Cbfa1 mRNA expression（P<0.05）.CONCLUSION: Angiotensin-(1-7) can inhibit beta-glycerophosphate-induced calcification in VSMCs through cAMP-PKA-Cbfa1 pathway and antagonize the effect of angiotensin II on calcification in VSMCs.     

Abnormal melanization and microstructural distortions of the shell of great scallop living in shallow water

Modifications of great scallop (Pecten moximus) shells have been noticed in many sites of scallop fisheries in Brittany, especially in shallow waters. These calcification abnormalities are linked to the appearance of a brown colouration of the internal calcified shell layer, due to the presence of a eumelanin associated with the insoluble organic matrix of the biocrystals. The appearance of this pigment generates many disturbances of the calcified foliated microstructure of the scallop internal shell layer. The mantle structure is not modified in brown shells as compared with white ones. No pathogenic signs such as hyperplasia or haemocytic infiltration have been observed. According to this observation, we hypothesize that the brown colour phenomenon is more a result of environmental disturbance rather than a symptom of a pathogenic disease.The colour abnormalities of the internal shell layer can be detected by a spectral analysis of its reflectance before it can be detected with the naked eye. This method, correlated to microstructural observations, gives a rapid and precise analysis of the appearance of the pigmentation on adult or juvenile scallops. It may be a useful method for the evaluation of the influence of environmental parameters, for example, on calcification and its abnormalities.     

海洋酸化对栉孔扇贝钙化、呼吸以及能量代谢的影响

通过Alkalinity anomaly technique测定了栉孔扇贝Chlamys farreri在不同酸度条件下的钙化率和呼吸率,发现栉孔扇贝的钙化和呼吸活动受酸化影响显著,均随着酸化的加剧出现了明显下降。当pH降低到7.9时,栉孔扇贝的钙化率将会下降33%左右;当pH降到7.3左右时,栉孔扇贝的钙化率将趋近于0,栉孔扇贝无法产生贝壳,而此时栉孔扇贝碳呼吸率(RC)与耗氧率(RO)也分别下降了14%和11%。随着酸化的加剧,栉孔扇贝的能量代谢方式也会发生改变。这些变化都可能影响到栉孔扇贝的生存。     

Taurine attenuated β-glycerophosphate-stimulated calcification in cultured rat vascular smooth muscle cells

AIM: To investigate the effect of taurine on calcification of vascular smooth muscle cells (VSMCs).METHODS: Calcified VSMCs of rat in vitro were induced by β-glycerophosphate. Cellular calcium content, alkaline phosphatase(ALP) activities and [⁴⁵Ca]accumulation were measured. DNA synthesis were evaluated by [³H]-thymidine ( [³H]-TdR) incorporation. RESULTS: Calcium content, ALP activities and [⁴⁵Ca]uptake of calcified VSMCs stimulated by taurine (5-20 mmol/L) were greatly decreased in a concentration-dependent manner as compared with calcified group (P＜0.01). Taurine also inhibited the proliferation of calcified cells in a concentration-dependent manner. Cell countingz, [³H]-TdR incorporation of calcified cells stimulated by taurine were greatly decreased as compared with calcified VSMCs (P＜0.01). CONCLUSION: It was demonstrated that calcification of VSMCs may be alleviated by taurine.     

热处理对冷藏板栗石灰化的影响

以河南确山红油栗为试材,经清水漂洗除去嫩粒后通风晾干,按随机方法分成105份样品,用食品保鲜袋(25cm×30cm)包装。然后分别以20℃、30℃和35℃温度处理4、8和12d后于0℃下贮藏,研究贮前热处理对板栗果实石灰化的影响。结果表明,贮前处理的温度愈高、时间愈长,板栗果实失水愈多、石灰化发生的比例愈大,冷藏期间石灰化发生程度愈严重。热处理后的板栗比对照果实更容易出现丙二醛(MDA)的积累。板栗石灰化指数与各指标的相关性分析表明,板栗石灰化与果实的水分损失和细胞膜的破坏关系最密切,2者是引起板栗石灰化的主要原因。     

活血化瘀中药对鸡实验性骨折愈合过程血清碱性磷酸酶及骨痂钙盐沉积的影响

为了给中药治疗骨折愈合提供动物实验依据, 将32只6月龄新罗曼母鸡, 体重1 75kg左右, 随机分为数目相等的两组, 中药组和对照组, 无菌手术条件下制备右肱骨中部一致性骨折模型, 骨折后中药组于饲料中添加1 5%复方中药(当归、川芎、桃仁、红花、血竭、土元、黄芪、川续断、骨碎补、乳香、没药、丹参、自然铜、大黄等量混合), 对照组常规喂料。骨折后3d、5d、10d和15d心脏采血检测血清碱性磷酸酶, 以骨折局部3d、5d、10d和15d的组织材料制作组织切片, 利用VonKossa氏法进行钙质染色检测骨痂钙盐沉积情况。结果: 中药组血清碱性磷酸酶活性骨折后6d、10d明显高于对照组, 差异极显著(P<0 01), 切片显示中药组骨折后10d和15d中药组钙盐沉积情况优于对照组。结论: 中药对鸡实验性骨折愈合有明显促进作用; 中药对鸡血清碱性磷酸酶活性, 骨痂钙盐沉积有促进作用。     

Role of endogenous angiotensin II in the pathogenesis of aortic calcification in rats

AIM: To explore the effects of angiotensin II on aortic calcification in the rat. METHODS: Arterial calcification of Sprague-Dawley rats was induced by vitamin D₃ plus nicotine. Calcification was confirmed by Von Kossa staining, measurement of calcium content, [⁴⁵Ca²⁺]accumulation and alkaline phosphatase (ALP) activity of vascular tissue. RESULTS: The results showed that calcium content, [⁴⁵Ca²⁺]accumulation and ALP activity in calcified arteries increased significantly compared with those of control. Ang Ⅱ levels in plasma and aortic tissues and the amount of angiotensinogen mRNA in calcified aorta were also increased as compared with control. Captopril (inhibitor of ACE) and losartan (Ang Ⅱ receptor inhibitor) decreased significantly the content of calcium, [⁴⁵Ca²⁺] uptake and ALP activity in calcified aorta. Ang Ⅱ levels in plasma and aortic tissues and the amount of angiotensinogen mRNA in aortic tissue were down-regulated by captopril. The amount of angiotensinogen mRNA and the content of Ang Ⅱ in the calcified aorta were also decreased by losartan. CONCLUSION: The captopril and losartan significantly alleviate the vascular calcification.