Atrial natriuretic peptide and verapamil can prevent gentamicin induced acute renal failure in the rat

Summary: Calcium channel blockers are able to improve renal function in acute renal failure (ARF) and natriuretic peptides can also exert beneficial effects. At present it is unknown whether administration of atrial natriuretic peptide (ANP) and a calcium channel blocker given before a toxic lesion can prevent gentamicin induced ARF. the mechanisms of action of natriuretic peptides and calcium channel blockers are different and, as yet, it has not been clarified if combined administration can augment the effects on renal function. After a basal period we investigated the effects of verapamil (VER, 0.66 mg/kg), ANP, (30 μg/kg) and a combination of both (identical doses as described individually). the drugs were given intravenously for a period of 40 min (infusion period) before gentamicin (15 mg/kg, i.v.) was administered for induction of ARF. Basal values for glomerular filtration rate (GFR, mL/min) were around 1.8 with no differences between the groups. At the end of the infusion period (before application of gentamicin) GFR was significantly elevated with VER + ANP (3.13 ± 0.51), ANP (2.70 ± 0.59) and VER (2.34 ± 0.47) compared to controls (saline, 1.7 ± 0.48). After application of gentamicin GFR significantly dropped in the control group (0.77 ± 0.21, 0.75 ± 0.19, respectively), indicating development of ARF. In contrast with VER + ANP, ANP and VER GFR could be maintained for 30 min (2.47 ± 0.39, 2.28 ± 0.33, 2.22 ± 0.43, respectively) and 130 min (2.11 ± 0.32, 1.86 ± 0.29, 2.11 ± 0.28, respectively) after gentamicin. Moreover ANP and VER revealed natriuretic activity and, due to their vasorelaxing potency, also influenced arterial blood pressure. We conclude that both VER and ANP are able to prevent early gentamicin induced ARF when given before the toxic lesion. Both drugs induce hyperfiltration while infused, in particular when administered in combination.     

高效液相色谱法测定硫酸奈替米星注射液的含量

目的采用高效液相色谱法测定硫酸奈替米星及注射液的含量。方法以μ-Diamonsil—C18为分析柱，流动相为1．5％的磷酸二氢钾-乙睛，流速为1．0ml／min，检测渡长为205nm。含量测定用峰面积外标法。结果硫酸奈替米星在0．1—1．6mg／ml浓度范围内呈现良好线性关系，r=0．9998．平均回收率为99．5％，RSD=0．4％（n=9）。结论本方法操作简便、快速，结果准确可靠，重现性好，均能很好地满足质量控制的要求，为开辟氨基糖苷类抗生素含量测定的仪器提供了一定借鉴。     

ALTERATION OF CHOLESTEROL SULFATE IN HUMAN SERA DURING THE COURSE OF PREGNANCY

Objective To determine the concentrations of cholesterol sulfate ( CS) in human sera and pla-cental villi during the course of pregnancy. And to analyze its inhibitory activity on thrombin and further characterize the functional significance of CS. Methods The concentrations of CS were determined by thin-layer chromatog-raphy (TLC) on 60 cases of normal pregnant women and 30 cases of normal placental villi. The effect of CS in human sera on the activity of thrombin was analyzed. Results The concentrations of CS in human sera gradually increased from the first to third trimester of gestation with a correlation coefficient of 0. 69, and a correlation between the concentration of CS and weeks of gestation (P <0. 01). CS was also contained in the placental villi, and its concentrations at the second and third trimester of gestations were 4. 7 and 6. 2-fold of that at the first trimester of gestation. CS inhibited the activity of thrombin. Conclusion Placental CS is one of the sources of CS in the serum , pr     

医用硫酸钙在家兔腰椎融合模型中的成骨能力

[目的]通过与自体髂骨进行比较,评价医用硫酸钙单独应用的成骨能力,并探讨其可能的成骨机理。[方法]建立家兔腰椎后外侧融合模型,以自身作为对照,双侧横突间植骨,左侧植入硫酸钙颗粒,右侧植入自体髂骨。于术后3、6、12周行X线、CT及组织学检查。[结果]术后3周,硫酸钙尚可见残留颗粒,自体骨完全降解;植骨区域内均可见到大量的破骨细胞,并有血管纤维组织长入。术后6周,硫酸钙完全降解,影像学检查两者之间没有明显的差异,表现为局部骨密度增高,新骨成形;组织学检查两侧植骨区内均为大量的透明软骨形成,自体髂骨植骨区内可见散在的骨小梁结构。术后12周,组织学及影像学上二者没有任何的差别,两侧形成的骨组织与家兔的椎体骨组织结构相同。[结论]医用硫酸钙作为骨移植替代材料,除了具有良好的骨传导性外,硫酸钙可能还具有骨诱导性,其成骨能力与自体髂骨相当,医用硫酸钙单独应用可以取得良好的融合效果。     

线性变温法研究硫酸链霉素粉针剂的稳定性

用线性变温法对硫酸链霉素粉针的稳定性进行了测定,得出25℃时的降解反应速度常数 k_(25)为1.744×10~(-6)h~(-1)、化学反应的表观活化能为107.9kJ/mol,25℃时贮存的 t_(0.9)为6.9年。     

Morphine-3-glucuronide: hyperglycemic and neuroendocrine potentiating effects

The greater potency of morphine-6-glucuronide (M6G) as well as the inactivity of morphine-3-glucuronide (M3G) with respect to the antinociceptive effects of the parent molecule, morphine (MOR), have been well established. It has been suggested that M3G is an antagonist of MOR's antinociceptive and respiratory depressive effects. The present study addressed the central nervous system (CNS) interaction of these opiate metabolites on their metabolic and hormonal effects. Whole body glucose kinetics were assessed on conscious, chronically catheterized, unrestrained rats. M3G (5 μg) or H₂O (5 μl) was injected intracerebroventricularly (i.c.v.) 15 min prior to the bolus administration of H₂O (5 μl), M6G (1 μg), or MOR (80 μg). i.c.v. M3G (5 μg) resulted in behavioral excitation, hyperglycemia (+50%), stimulation of glucose rate of appearance (R_a; +100%), glucose rate of disappeaance (R_d; +70%), and metabolic clearance rate (MCR; +33%) within 30 min after injection with no alterations in hormone concentrations. i.c.v. M6G and MOR produced progressive hyperglycemia with significantly high catecholamine and corticosterone levels. M3G pretreatment resulted in enhanced elevations in plasma glucose levels (+52% and +18%), plasma lactate (+138% and +108%), norepinephrine (+96% and +30%), and epinephrine (+62% and +67%) in response to both i.c.v. MOR and M6G administration. These findings suggest a non-opiate and non-hormonal mechanism for M3G-induced hyperglycemia. In contrast, the metabolic and hormonal responses to i.c.v. M6G and MOR are associated with elevations in catecholamine and corticosterone levels, which are remarkably enhanced by M3G pretreatment, most likely through accelerated catecholamine release. Our findings suggest a modulatory role for MOR glucuronidation, not only by rendering it inactive, as in the case of M3G, but by an interplay of the metabolic effects of the parent molecule and its metabolite     

Patch testing with beryllium alloy samples in guinea pigs

An experimental study was conducted in guinea pigs for the predictive assessment of the beryllium alloy hazard in occupational exposure of the skin to beryllium compounds. Guinea pigs were sensitized to beryllium sulfate according to the maximized Magnusson and Kligman test, and challenged with beryllium alloys and metallic copper, beryllium and aluminum samples. Results showed a delayed skin hypersensitivity reaction in 30 to 60% of pre-sensitized guinea pigs challenged with copper-beryllium alloys and aluminum-beryllium alloy. An inflammatory follicular reaction was induced by copper in both controls and pre-sensitized guinea pigs.     

Colonic Drug Delivery: Enhanced Release of Indomethacin from Cross-Linked Chondroitin Matrix in Rat Cecal Content

Pharmaceutical Research -     

硫酸镁联合亚低温治疗对大鼠局灶性脑缺血的保护作用

目的　探讨硫酸镁对SD大鼠局灶性脑缺血损伤的保护作用。方法　将 4 0只大鼠随机分成模型对照组、硫酸镁治疗组、亚低温治疗组、硫酸镁联合亚低温治疗组。采用线栓法建立大鼠局灶性脑缺血模型。通过计算大鼠神经功能缺陷评分 ,测量脑梗死体积 ,观察神经元超微结构改变 ,评定硫酸镁联合亚低温治疗作用。结果各治疗组大鼠神经功能评分及脑梗死体积均显著低于对照组 (P <0 0 5 ) ,联合治疗组大鼠明显低于对照组 (P<0 0 1) ;联合治疗组神经元超微结构改变轻微。结论　硫酸镁联合亚低温治疗对大鼠局灶脑缺血有明显保护作用     

爱大霉素和庆大霉素对肾皮质线粒体~(45)Ca~(2+)摄取的影响

目的研究爱大霉素和庆大霉素对大鼠肾皮质线粒体钙摄取的影响。方法应用４５Ｃａ２＋示踪技术。结果两药在１ｍｍｏｌ·Ｌ－１时显著促进线粒体钙摄取（分别由每３０ｍｉｎ（１１３．５±７．５）μｍｏｌ·ｇ－１Ｐｒｏ上升到（１４８．０±２４．０）μｍｏｌ·ｇ－１Ｐｒｏ，（１１１．９±１３．０）μｍｏｌ·ｇ－１Ｐｒｏ上升到（１４０．１±１６．６）μｍｏｌ·ｇ－１Ｐｒｏ，Ｐ＜０．０５）；在１０μｍｏｌ·Ｌ－１时显著抑制线粒体钙摄取（分别由每３０ｍｉｎ（１１３．５±７．５）μｍｏｌ·ｇ－１Ｐｒｏ下降到（９２．３±５．７）μｍｏｌ·ｇ－１Ｐｒｏ，（１１１．９±１３．０）μｍｏｌ·ｇ－１Ｐｒｏ下降到（１４０．０±５．３）μｍｏｌ·ｇ－１Ｐｒｏ，Ｐ＜０．０５或Ｐ＜０．０１）。结论两药对线粒体钙摄取的这种双相变化可能与它们肾毒性有关