Inefficiency of intracerebroventricular ANP to alter haemodynamic,plasma vasopressin and renin responses to haemorrhage in sheep

Whether intracerebroventricular (i.e.v.) infusion of atrial natriuretic peptide (human-ANP, 1–28) 25 pmol min^-1 influences the tolerance to blood loss and haemorrhage induced cardiovascular, vasopressin and renin responses were studied in five conscious sheep. The i.e. v. infusion was started 60 min prior to a slow (0.7 ml kg^-1 min^-1) venous haemorrhage, was run concurrently with bleeding, and for 90 min thereafter. Venous blood was removed until the mean systemic arterial pressure suddenly fell to about 50 mmHg. There were no statistically significant differences in either the bleeding volume necessary to induce the sudden decrease in blood pressure, or in cardiovascular parameters measured by venous heart thermodilution catheterization, compared with control experiments with i.e.v. infusion of artificial CSF. The plasma protein and vasopressin concentrations and renin activity were unaffected by the i.c.v. infusion of ANP as were the changes in these parameters occurring during the subsequent haemorrhage. The same negative findings were obtained with a three times higher dose of ANP(l-28) (75 pmol min^-1), tested in three of the animals. Thus the i.c.v. infusion of ANP(l-28), in amounts expected to elevate the CSF concentration far above basal levels does apparently not influence normal blood pressure regulation or alter haemodynamic, vasopressin and renin responses to haemorrhage in conscious sheep.     

窒息新生儿心钠素及肌酸激酶、同工酶MB的动态观察及其临床意义

目的：探讨心钠素（ＡＮＰ）在新生儿窒息中的作用及同时检测肌酸激酶同工酶ＭＢ（ＣＫ－ＭＢ）的临床意义。方法：应用放射免疫法检测４８例窒息新生儿生后２天、７天血浆ＡＮＰ的含量,同进检测ＣＫ－ＭＢ的含量,并与２０例足月健康儿对照。结果：（１）ＡＮＰ水平轻度窒息组高于正常对照组,重度窒息组高于轻度窒息组,均有显著性差异;随着窒息与缺氧的好转,ＡＮＰ逐渐下降;（２）ＣＫ－ＭＢ与窒息程度呈正相关,各组间差异显著;（３）ＡＮＰ与ＣＫ－ＭＢ二者关系。在轻度窒息组正相关无意义,在重度窒息组正相关意义显著。结论：ＡＮＰ参与了窒息时生理病理调节,同时测定ＡＮＰ及ＣＫ－ＭＢ是估计病情及预后的客观指标。并有利于治疗,改善预后。     

Plasma immunoreactive atrial natriuretic peptide and vasopressin after ethanol intake in man

To study the mechanisms of alcohol-induced diuresis, the plasma concentration of immunoreactive atrial natriuretic peptide and arginine vasopressin, serum sodium and osmolality, plasma renin activity and aldosterone, urinary sodium and volume, free water clearance, blood pressure and heart rate were measured in seven healthy men after oral intake of ethanol (1.5 g kg^-1 in 6 h). Serum ethanol levels increased to 27 ± 4 mmol 1^-l (mean ± SD) in 30 min and remained detectable for 14 h. Serum osmolality rose from 280±10 to 340 ± 4 mosm kg^-1 in 2 hours (P < 0.01) and was 300 ± 4 at 14 h (P < 0.01). Formation of hypotonic urine began after the alcohol intake and resulted in a net loss of 0.9 ± 0.1 kg water in 2 h. Free water clearance increased from -3.4 ± 1.4 to 2.8 ± 1.5ml min^-l in 2 h (P < 0.01). Plasma immunoreactive arginine vasopressin decreased from 5.7 ± 2.1 to 3.3 ± 1.3 ng 1^-1 (P = 0.05) in 30 min and increased to 17 ± 25 and 12±10 ng 1^-1 at 6 and 12 h, respectively (P < 0.05 for both). Plasma immunoreactive atrial natriuretic peptide levels decreased from 17 ± 9 to the minimum of 11 ± 3 ng 1^-1 in 2 h (P < 0.01) and returned to the initial levels in 6 h. Serum sodium, plasma renin activity and plasma aldosterone increased maximally by 4 ± 2 , 165 ± 153 and 143 ± 101 % (P < 0.01 each) during 1–6 h. No changes in blood pressure were observed during the ingestion period, but the heart rate rose significantly from 70 min^-1 at 6 p.m. to 95 min^-1 at 12 p.m. We conclude that ethanol intake in relation to serum ethanol levels caused in the first phase a rapid increase in osmolality which was associated with a decrease in plasma immunoreactive arginine vasopressin. This caused hypotonic diuresis and increased free water clearance followed by volume contraction which evidently led to decreased plasma immunoreactive atrial natriuretic peptide. Serum osmolality was significantly elevated during the whole experiment and serum sodium 1–2 h after the ethanol intake. This was associated with the return of plasma immunoreactive atrial natriuretic peptide to initial levels after 6 h, the increase in plasma immunoreactive arginine vasopressin levels and reduced diuresis after 2 h. Our results suggest that ANP is not responsible for the diuresis seen after the alcohol intake.     

附子与干姜不同比例配伍对急性心衰大鼠神经激素释放的影响

目的考察附子干姜不同比例配伍前后对急性心衰大鼠神经激素释放的影响。方法建立戊巴比妥钠致大鼠急性心衰动物模型,用ELISA法测定急性心衰大鼠血浆氨基末端脑钠肽原(NT-pro BNP)、心钠素(ANP)、肾素活性(PRA)、血管紧张素Ⅱ(AngⅡ)、醛固酮(ALD)含量。结果附子干姜配伍后均可降低急性心衰大鼠血浆NT-pro BNP、心钠素(ANP)、肾素活性(PRA)、血管紧张素Ⅱ(AngⅡ)、醛固酮(ALD)的含量,其中附子干姜配伍后作用明显优于附子组,尤以附子干姜1∶1组作用最强。结论附子干姜配伍能够调控急性心衰大鼠部分神经激素的释放,从而延缓急性心衰的发展。     

黄芪多糖对异丙肾上腺素诱导的乳大鼠心肌细胞肥大的保护作用

目的探讨黄芪多糖(APS)对异丙肾上腺素(isoprot-erenol,Iso)诱导的乳鼠心肌细胞肥大的保护作用及机制。方法以原代培养乳鼠心肌细胞为模型,应用Iso 10μmol.L-1诱导心肌细胞肥大,观察不同浓度的黄芪多糖及L型钙通道阻滞剂维拉帕米(Verapamil,VER)对心肌肥厚的影响。用Lowry法测心肌细胞蛋白含量;消化分离法及计算机图像分析系统测细胞体积;RT-PCR法检测心肌细胞ANP的mR-NA表达;以Fluo-3/AM为荧光探针,采用激光共聚焦显微镜观察细胞内[Ca2+]i的变化。结果 APS和VER均能够有效抑制Iso诱导的心肌细胞肥大,表现为蛋白质含量降低,体积减小,ANP mRNA表达降低和细胞内钙离子浓度降低,且APS的作用呈一定的剂量依赖性。结论黄芪多糖对Iso诱导乳大鼠心肌细胞肥大有保护作用,其机制可能与降低[Ca2+]i有关。     

急性颅脑损伤后血Na+及相关激素变化的临床研究

目的：探讨血抗利尿激素（ADH）、皮质醇（Cortisol)、醛固酮（ALD）变化在急性颅脑损伤（ACI）中的意义及其对血钠的影响。方法：对2002年3－9月收治的72例ACI患者血中ADH、ANP、Cortsiol,ALD浓度及血清Na^ ，K^ ,Cl^-,Ca^2 进行同步监测。结果：ACI患者血ADH，Cortisol浓度显著高于对照组，血ANP浓度显著低于对照组，随病情进展，血ADH，Cortisol浓度增高显著高于伤后早期，血ANP的浓度显著低于伤后早期，结论：ACI导致下丘脑－垂体－肾上腺轴功能障碍，机体存在有效的调节代偿机制而不致发生严重的电解紊乱，脑外伤越重，机体调节代偿功能越差。     

对充血性心力衰竭患者血浆ANP、NO的影响

采用静脉滴注复方丹参、黄芪注射液治疗３０例充血性心力衰竭（ＣＨＦ）,另设正常对照组３０例,以观察其对ＣＨＦ患者血浆心纳素（ＡＮＰ）、一氧化氮（ＮＯ）、内皮素（ＥＴ）、降钙素相关基因肽（ＣＧＲＰ）浓度的影响。结果：治疗组治疗２周后,ＡＮＰ显著降低（Ｐ＜００１）,ＮＯ明显上升（Ｐ＜００５）,且接近正常组水平（Ｐ＞００５）,ＥＴ、ＣＧＲＰ治疗前后与正常组无显著差异（Ｐ＞００５）;心功能较治疗前普遍改善１级。提示复方丹参、黄芪注射液能改善ＣＨＦ患者血管内皮细胞功能,促进ＮＯ的释放。