Spatial association of renin-containing cells and nerve fibers in developing rat kidney

The development of renin-containing cells and nerve fibers was studied in Sprague-Dawley rat kidneys during the last third of gestation and the first 15 days of postnatal life. Kidney tissue sections were stained for nerve fibers or double stained employing an anti-rat renin polyclonal antibody and a monoclonal antibody (TUJ1) directed against a neuron-specific class III beta-tubulin isotype. Renin-containing cells and nerve fibers were detected at 17 days of gestation, in close spatial relationship along the main branches of the renal artery. During fetal life, renin-containing cells and nerve fibers were spatially associated along arcuate and interlobular arteries, renincontaining cells being also present throughout the entire length of afferent arterioles supplying juxtamedullary glomeruli. During postnatal life the distribution of renincontaining cells progressively shifted to a restricted juxtaglomerular position in afferent arterioles. Simultaneously, density and organization of nerve fibers increased with age along the arterial vascular tree. Our results suggest that innervation of renin-containing cells is present in fetal life and follows the centrifugal pattern of renin distribution and nephrovascular development.     

Influence of repeated cocaine exposure on the endocrine and behavioral responses to stress in rats

Previous studies have determined that chronic cocaine exposure inhibits the serotonergic stimulation of hormone secretion. The present experiments were conducted to determine whether the endocrine responses to stress could be a useful approach to assess the influence of cocaine exposure on neuronal function. Male rats received twice daily injections of cocaine (1–15 mg/kg, IP) for 7 days. Animals were subsequently exposed to different stressors, i.e. conditioned emotional stress utilizing a low (0.5 mA) or high (1.5 mA) intensity footshock during training, or to immobilization stress. Immediately after the stress procedures, blood samples were collected for radioimmunoassay of plasma corticosterone, prolactin, and renin concentrations. Repeated cocaine exposure attenuated the stress-induced elevations of corticosterone and prolactin secretion, and attenuated some of the behavioral effects of the low intensity conditioned emotional stress. When exposed to the high intensity conditioned emotional stress, cocaine did not alter the endocrine or behavioral effects of stress. Finally, repeated cocaine exposure modified the immobilization stress-induced elevation of renin secretion; low doses of cocaine (1 or 5 mg/kg) attenuated, while higher doses (10 mg/kg) potentiated the renin response to immobilization stress. Thus, the influence of repeated cocaine exposure on the endocrine and behavioral responses to stress appears to depend upon the type and intensity of the stressor. Compared with previous studies which found altered neuroendocrine responses to serotonin releasers and agonists following cocaine exposure, the hormonal responses to stress are less consistently modified by cocaine.     

经导管选择性静脉采血技术对肾血管性及异体肾移植术后高血压的应用

采用选择性静脉导管分段取血对10例肾血管性和3例异体肾移植术后高血压病人测定肾素活性水平,比较左右肾静脉和下腔静脉肾素活性的比值,判定肾动脉狭窄取得了满意的结果。异体肾移植术后高血压患者行分测移植肾和自体病肾静脉血肾素活性,发现自体病肾静脉血肾素活性明显高于移植肾,动脉造影证明移植肾动脉无狭窄。为病肾肾素依赖性高血压。用无水乙醇枪塞自体病肾动脉,结果有效。     

Multiple risk factor clustering and risk of hypertension in the Mongolian ethnic population of China

Objective To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension (EH) and the accumulation of risk factors influences the blood pressure level in normotensives. Methods On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity (243 hypertensives and 258 normotensives) who were not related to each other were selected to conduct a case-control study. All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion (I/D) polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis. Results Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH (P<0.05). The odds ratios (OR) for the number of risk factors were 2.39 (95%CI: 0.98-6.74) for one risk factor, 5.03 (95%CI: 2.06-14.18) for two, and 6.09 (95%CI: 1.85-22.38) for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors. However, there were no significant differences among the different blood pressure levels according to the number of risk factors (P>0.05). Conclusion Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.     

Activity of Erythropoietin and Renin in Renal Venous Blood of Hypertensive Patients

Plasma activities of renin and erythropoietin were determined in the renal veins of the right and left kidneys of hypertensive patients. The patients were divided into the following groups either according to the origin of the hypertension (group 1: control or essential hypertension, group 2: renovascular hypertension) or according to the hormone levels (group 3: renin activity exceeding 10 ng/litre in at least one of the renal veins and group 4: erythropoietin activity higher than 4% 5 9Fe incorporation in at least one of the renal veins). In groups 1, 2 and 3 a statistically significant difference in renin activity was found between the kidney with the higher renin activity and that with the lower activity However, in group 4, the side, which showed elevated erythropoietin values also had higher renin activity as compared to the essential hypertensive group. Erythropoietin activity probably does not parallel the increased renin activity found in renovascular hypertension or in some cases of non-renovascular hypertension. However, in several cases of renal vascular alterations, both systems can be activated simultaneously.     

Effect of Renin‐Angiotensin System Inhibitor on Residual Glomerular Filtration Rate in Hemodialysis Patients

Residual renal function preservation in patients with renal failure has been shown to be related to better outcomes not only in the pre‐dialysis phase but also after hemodialysis initiation. However, the effect of factors such as antihypertensive agents on residual renal function preservation has not been investigated adequately in prevalent hemodialysis patients. This study examined factors related to the rate of residual renal function preservation in 1‐year hemodialysis patients who had residual renal function. We enrolled 191 consecutive maintenance hemodialysis patients who underwent hemodialysis for 1 year and maintained a urine output of more than 200 mL/day, to assess residual renal function loss. The rate of residual renal function loss was 19.9%. Multivariate analysis using residual renal function as the dependent variable revealed significant independent relationships with renin‐angiotensin system inhibitor use (hazard ratio, 0.438; P = 0.027), history of cardiovascular disease (hazard ratio, 2.475; P = 0.024), and rate of weight gain between dialysis sessions (hazard ratio, 1.348; P = 0.013). No relationship was observed with calcium channel blocker use. Renin‐angiotensin system inhibitor use, rate of body weight gain between dialysis sessions, and cardiovascular diseases are independently associated with residual renal function preservation in patients with residual renal function after 1 year of hemodialysis. A further intervention study is required to investigate whether treatment with renin‐angiotensin system inhibitors and suppression of body weight gain preserves residual renal function for a longer time in hemodialysis patients.     

Basal and exercise-induced neuroendocrine activation in patients with heart failure and in normal subjects

BACKGROUND: Neuroendocrine activation is a pathophysiological response and an important prognostic marker in patients with chronic heart failure (CHF). Although chronic activation is well described, data on the responsiveness of the hormone systems are more limited. Most previous studies have looked at activation during maximal exercise, whereas we believe that activation at a submaximal level might be more pathophysiologically relevant. AIM: To compare exercise-induced neurohormonal activation between CHF patients and normal subjects using the same relative and submaximal workload. Subjects: Twenty-three newly-diagnosed CHF patients and 18 age- and gender-matched healthy subjects were exercised at two workloads, which were calculated to correspond to 50 and 75% of each individual's heart rate response. RESULTS: In CHF patients, baseline levels of ANP, BNP, AVP, PRA and ET-1 were elevated compared to healthy subjects. Exercise induced an increase in ANP, A and NA in both CHF patients and in normal subjects, however BNP was only increased in CHF patients and not in normal subjects. CONCLUSION: When CHF patients exercise at the same relative and submaximal level as age-matched healthy subjects, the relative increases in ANP, A and NA were similar, however, BNP levels only increased in the CHF group.     

心房颤动患者循环血浆肾素、血管紧张素Ⅱ和醛固酮的变化及临床意义

目的 分析心房颤动患者循环血浆肾素、血管紧张素Ⅱ(AngⅡ)、醛固酮(Ald)的水平变化,并探讨其临床意义。方法入选42例患者,男19例,女23例,年龄37-80(63.02±10.66)岁。按有无心房颤动病史分为三组:窦性心律组(SR组)14例,阵发性心房颤动组(pAF组)15例,慢性心房颤动组(cAF组)13例。应用放射免疫方法测定循环血浆肾素、AngⅡ、Ald浓度。结果cAF组患者平均左心房直径与SR组和pAF、组相比明显增大(分别增大45.3％和31.8％,P<.01),而且cAF组患者循环血浆肾素、AngⅡ、Ald浓度与SR组相比明显升高(分别升高83.3％、61.7％、34.2％,P<0.01-0.02)。三组患者左心房直径与其循环血浆肾素、AngⅡ、Ald浓度变化具有明显的正相关关系(P<0.05-0.01)。结论心房颤动时存在肾素-血管紧张素系统(RAS)和Ald的激活。RAS和Ald可能参与了心房结构重构的发生。Ald的作用靶点可能主要是心房间质。     

血栓抽吸治疗急性ST段抬高型心肌梗死前后神经内分泌因子水平的变化

目的探讨应用血栓抽吸装置GuardWire Plus^TM行血栓抽吸治疗急性sT段抬高型心肌梗死（STEMI）对神经内分泌因子水平、外周血肌钙蛋白（cTnI）、TIMI血流变化的影响及其临床价值。方法将2004年9月至2006年9月在我院行急诊PCI的72例STEMI患者分为两组，抽吸组（TA组，38例）血栓抽吸后支架置入；非抽吸组（NTA组，34例）单纯PCI。于手术当天、术后第1、2、3、5天分别测定外周血中内皮素（ET）、血浆肾素活性（PRA）、醛固酮（ALD）、血管紧张素Ⅱ（AngⅡ）、去甲肾上腺素（NE）、肾上腺素（E）的水平。于术前、术后4h、8h、12h、16h、24h、2d、3d、5d分别测定外周血中cTnI的水平。支架置入后常规行冠状动脉造影，观察心肌血流灌注情况，测定支架置入后两组患者的TIMI血流。比较术后2h心电图ST段回落。术后1周及3个月应用彩色超声心动图测定左室射血分数（LVEF），评价心功能。结果两组病例均成功置入支架，术前两组患者的神经内分泌因子水平均显著升高，两组间差异无统计学意义。浓度-时间曲线显示术后神经内分泌因子水平均迅速下降，TA组较NTA组ET、PRA、AngⅡ、ALD、NE、E等神经内分泌因子水平于术后第1天或第2天下降明显[ET：术前152．37ng／L比153．63ng／L（P：0．858），术后第1天128．11ng／L比147．07ng／L（P=0．037），术后第2天122．22ng／L比139．64ng／L（P=0．040）；PRA：术前2．87μL／（L·h）比2．87μL／（L·h）（P=0．998），术后第1天1．74μL／（L·h）比2．54μL／（L·h）（P=0．036），术后第2天1．70μL／（L·h）比2．29μL／（L·h）（P=0．032）；ALD：术前200．14pmol／L比181．19pmol／L（P=0．508），术第1天156．06pmol／L比172．19pmol／L（P=0．001）；AngⅡ：术前199．11ng／L比。212．32ng／L（P=0．539），术后第1天149．26ng／L比188．37ng／L（P=0．040），术后第2天135．57