长期给予不同钙拮抗剂对大鼠胰岛功能和胰岛素敏感性的影响

目的观察不同钙拮抗剂对SD大鼠B细胞功能、胰岛素敏感性的作用。方法实验分为对照组、维拉帕米组、地尔硫卓组以及尼卡地平组。每组腹腔注射不同药物,4周后利用静脉糖耐量实验技术(IVGTT)观察各组大鼠胰岛B细胞分泌功能的变化;给药期间记录各组大鼠体质量的变化;并通过给药前后空腹血糖、空腹血清胰岛素水平的变化,计算胰岛素敏感指数(ISI)和胰岛素抵抗指数(HOMA-IR)以反应钙拮抗剂改善胰岛素敏感性的作用。结果与对照组相比,钙拮抗剂维拉帕米、地尔硫卓和尼卡地平可以降低SD大鼠的体质量,增加ISI,降低HOMA-IR,其中以地尔硫卓最明显。结论长期应用钙拮抗剂对大鼠具有降低体质量和改善胰岛素敏感性的作用,但对胰岛功能无明显影响。     

A Comparative Study on Several Models of Experimental Renal Calcium Oxalate Stones Formation in Rats

In order to compare the effects of several experimental renal calcium oxalate stones formation models in rats and to find a simple and convenient model with significant effect of calcium oxalate crystals deposition in the kidney, several rat models of renal calcium oxalate stones formation were induced by some crystal-inducing drugs (CID) including ethylene glycol (EG), ammonium chloride (AC), vitamin D3 [1α(OH)VitD3, alfacalcidol], calcium gluconate, ammonium oxalate, gen-tamicin sulfate, L-hydroxyproline. The rats were fed with drugs given singly or unitedly. At the end of experiment, 24-h urines were collected and the serum creatinine (Cr), blood urea nitrogen (BUN), the extents of calcium oxalate crystal deposition in the renal tissue, urinary calcium and oxalate ex-cretion were measured. The serum Cr levels in the stone-forming groups were significantly higher than those in the control group except for the group EG L-hydroxyproline, group calcium gluconate and group oxalate. Blood BUN concentration was significantly higher in rats fed with CID than that in control group except for group EG L-hydroxyproline and group ammonium oxalate plus calcium gluconate. In the group of rats administered with EG plus Vitamin D3, the deposition of calcium ox-alate crystal in the renal tissue and urinary calcium excretion were significantly greater than other model groups. The effect of the model induced by EG plus AC was similar to that in the group in-duced by EG plus Vitamin D3. EG plus Vitamin D3 or EG plus AC could stably and significantly in-duced the rat model of renal calcium oxalate stones formation.     

血清钙邻-甲酚酞络合酮测定中试剂加入方法的评价

目的:评价血清钙邻-甲酚酞络合酮(OCPC)测定中试剂两种不同的加入方法。方法:第1种试剂加入方法,按说明书操作,试剂乙醇胺缓冲液(R1)与试剂OCPC(R2)预先混合成工作液,然后再加入样品管中;第2种试剂加入方法:R1与R2试剂按顺序直接加入样品管中,混合后测定。对第2种试剂加入方法测定结果同全自动生化分析仪比较并对该法的精密度和准确度作了实验观察。结果:按说明书操作,我室的室间质评血清钙VIS在0~289之间,而采用第2种试剂加入方法,我室连续3a血清钙PT得分全部为100,30份标本分别用该法及全自动生化分析仪测定,两组结果相比较差异无显著性,具有良好的相关性(r=0.986,P<0.01)。平均回收率99.5%,批内CV为4.03%,批间CV为5.6%%。结论:第2种试剂加法简便、快速、准确且克服干扰,适合临床实验室推广应用。     

茅莓总皂苷对大鼠海马神经元细胞缺氧损伤后胞内钙超载的影响

目的研究茅莓总皂苷对原代培养大鼠海马神经元缺血损伤后胞内钙超载的影响。方法大鼠海马神经元培养后,用Fluo-2/AM负载培养的神经细胞,氧糖剥夺30min,在激光共聚焦显微镜下监测加入茅莓总皂苷后海马神经元的[Ca2+]i的变化。结果茅莓总皂苷10-5,10-4,10-3g·L-1和Nim10-5mol·L-1组能不同程度地降低大鼠海马神经元细胞内[Ca2+]i。结论茅莓总皂苷可通过减轻细胞内的钙超载来对缺血神经元进行保护。     

A Discordant Movement in Urine Calcium Excretion in Relation to Serum Calcium and Parathyroid Function Occurring Immediately after Birth

ABSTRACT. We studied the relationship between serum calcium and urinary calcium excretion in association with the parathyroid function in 28 neonates at birth and at five days of age. At birth, the urine calcium was low in spite of high cord serum calcium and a low parathyroid hormone level. On the fifth day of birth, urinary calcium excretion increased despite the reduction in serum calcium and an increase in the parathyroid hormone. These results suggest that the large increase in renal blood flow and the consequent increase in calcium load on the immature renal tubule occurring after birth may be the main cause for the change in this serum calcium-urinary calcium relationship. This finding can in part explain the temporary hypocalcemia during this period.     

对虾中的钙在大鼠体内的吸收利用

以对虾加工后废弃的虾头、壳为原料制成三种对虾钙。用三种对虾钙、脱脂奶粉、活性离子钙配制的饲料及基础低钙饲料,喂养6组大鼠30天,并做3天代谢试验。结果是:奶粉、对虾钙、活性离子钙组鼠体重净增值分别为(g):91.15、57.17、28.04;钙吸收率(％);81.5、79.8、60.7;钙储留率(％):98.1、81.6、67.3;股骨钙存留率(％):5.37、3.36、2.91;钙利用率(％):84.0、53.0、36.8。结果表明:对虾钙在大鼠体内吸收、利用、储留效果和促进生长发育等比活性离子钙好,次于脱脂奶粉,可作为补充机体钙的良好来源。     

Smooth muscle relaxant activities of compounds isolated from malaysian medicinal plants on rat aorta and guinea-pig ileum

Muscle relaxant activities of six compounds isolated from Malaysian medicinal plants were investigated on the smooth muscles of the rat aorta and longitudinal muscle of the guinea-pig ileum. Except for goniothalamin, the other five compounds exhibited varying degrees of muscle relaxant activities on the two smooth muscles. Dicentrine, isocorydine, altholactone and usnic acid reduced the contractions to KCI and phenylephrine in the rat aorta, whilst atranorin slightly reduced the contractions to phenylephrine but not KCI. In addition, dicentrine and isocorydine markedly reduced the contractile response to phenylephrine in Ca²⁺-free Krebs solution. In the longitudinal muscle of the guinea-pig ileum, altholactone, atranorin, dicentrine and isocorydine inhibited to a greater extent the phasic than the tonic responses to KCI. All four compounds similarly inhibited the contractions induced by ACh. The results suggest that the relaxant activities of the compounds are attributed mainly to inhibition of Ca²⁺ influx via the calcium channels in the membrane of the smooth muscles. Furthermore, the greater sensitivity of dicentrine, isocorydine and altholactone against phenylephrine-induced contractions or KCI-induced phasic contractions are due to their abilities to inhibit intracellular Ca²⁺ release in these muscles.     

激光扫描共聚焦显微镜的原理与生物学应用

激光扫描共聚焦显微镜在光学显微镜基础上结合了激光和计算机图象处理技术，把光学显微镜的分辨率提高了３０－４０％，其光学切片性能使观察组织、细胞的三维结构成为可能。本文简要介绍了共聚焦显微镜的历史和成象原理，着重介绍了其在生物学领域的应用，如样品的三维定量测量及活细胞的动态信号监测，并结合新兴的光生物学技术，如光镊、笼锁化合物的解笼锁、细胞分选、光漂白后的荧光恢复，探讨了激光共聚焦显微镜在激光细胞生物学的应用前景     

Phosphorus Deficiency Syndrome in Two Very Low Birthweight Infants

Biochemical and radiographic abnormalities linked with phosphorus deficiency syndrome (PDS) developed in two very low birthweight (VLBW) infants fed exclusively with human milk. By increasing phosphorus (P) and calcium (Ca) intakes with the introduction of a specialized premature formula, osteopenia or rickets, as well as hypophosphatemia, hypo-phosphaturia and increased serum alkaline phosphatase levels improved in both patients. We speculated that all VLBW infants who are being fed exclusively with human milk should be monitored for PDS and that if PDS develops, supplementation of human milk with both P and Ca appears to be necessary for its treatment.