Effects of insulin on plasma renin activity, plasma atrial natriuretic peptide and body fluid volume in diabetes mellitus

The effects of insulin treatment on plasma renin activity (PRA), plasma atrial natriuretic peptide (ANP) and body fluid volume were studied in 16 hospitalized patients with insulin-independent diabetes mellitus. Parameters were recorded for 2 days during treatment by diet alone and for 3 weeks after starting insulin. Blood samples were obtained weekly from 9 patients for the measurement of fasting plasma glucose, hematocrit, PRA and plasma ANP. A 24-hr urine sample was collected to determine the urinary excretion of glucose and sodium. In a separate group of 7 patients, plasma volume and extracellular fluid volume were determined by the Evans blue and sodium thiocyanate dilution tests, respectively. In the group of 9 diabetic patients, significant (p less than 0.05) reductions in fasting plasma glucose, hematocrit and the urinary excretion of sodium and glucose were seen with insulin treatment. PRA fell significantly (p less than 0.05) from 5.2 +/- 1.2 ng/ml/hr (mean +/- SEM) on the control days to 2.3 +/- 0.5 on the 21st day after starting treatment. Plasma levels of ANP averaged 35 +/- 5 pg/ml on the control days and these did not change significantly. In the other group of 7 patients, both plasma volume and extracellular fluid volume increased significantly (p less than 0.05) with insulin treatment. A sodium-retaining effect of insulin and a decrease in osmotic diuresis may have increased the body fluid volume and caused the fall in PRA. Thus, a vasodilatory action of insulin may assist in compensation for the increase in body fluid volume, preventing a rise in plasma ANP levels.     

The interaction of plasma renin activity and plasma atrial natriuretic peptide in 21-hydroxylase deficiency patients

Plasma renin activity (PRA) determination is the main index used to evaluate the mineralocorticoid control in 21-hydroxylase deficiency (21-OHD). PRA values within or at the upper limit of the age-appropriate range, or values <5 or 10 ng/ml/h have been regarded as adequate control. Atrial natriuretic peptide (ANP) has opposite actions to those of angiotensin II/aldosterone, and could help to understand the hydrosaline homeostasis in 21-OHD. We studied the interaction between PRA and ANP levels in 10 controls and 26 patients with 21-OHD under corticoid treatment. Patients were divided into two groups according to PRA levels, < or > or = 5 ng/ml/h, irrespective of the clinical form of 21-OHD. Blood samples for determination of PRA and ANP levels were taken after 30 min in the sitting position (basal), after 30 min in the recumbent position and after 15 min of 20 degrees head-down tilting. ANP levels (pg/ml) in the basal, supine and after head-down tilting position were 25.9 +/- 1.6, 42.7 +/- 7.4 and 54.3 +/- 5.5 in controls; 28.5 +/- 2.1, 38.3 +/- 2.1 and 48.8 +/- 4.1 in the group with PRA levels <5 ng/ml/h, and 20.9 +/- 1.9, 26.6 +/- 2.5 and 34.6 +/- 3.1 in the group with PRA levels > or = 5 ng/ml/h, respectively. Basal and after head-down tilting ANP plasma levels were similar between the controls and the group with PRA levels <5 ng/ml/h. However, the group of patients with PRA levels > or = 5 ng/ml/h showed lower basal and stimulated ANP levels compared to the control group (p<0.05). The decreased plasma ANP levels in the basal condition and after head-down tilting indicate a chronic contraction of the extracellular volume in 21-OHD patients with increased PRA levels. Therefore, mineralocorticoid deficiency is counteracted by decreased ANP secretion in order to preserve fluid and electrolyte homeostasis.     

Atrial natriuretic peptide and plasma renin activity in patients with stable chronic obstructive pulmonary disease]

The relationship between plasma atrial natriuretic peptide (ANP) and plasma renin activity (PRA) was examined in patients with stable chronic obstructive pulmonary disease (COPD, n = 17). The plasma ANP level in patients was approximately twice that in normal subjects. A reciprocal relationship between ANP and PRA was shown in normal subjects; however, this relationship was not observed in COPD. Plasma ANP levels inversely correlated with PaO2, and tended to inversely correlate with angiotensin converting enzyme activity in serum. These results demonstrate that patients with COPD have higher plasma ANP concentration, and that ANP and PRA are not reciprocally related in stable COPD.     

闭式腹水回收32次分析

自1990年3月以来，对经强化透析超滤不能消除腹水，并在透析过程中不断出现低血压的3例慢性维抟性血透患者，成功地进行了32人闪的静脉腹水回收，其特点是将回收腹水同传统的血透相结合，治疗中腹水被间断或边疆地通过管道泵入透析器或血滤器，在其中同血液一起进行透析，并按腹水回收容量同步地超滤，治疗后患者体力不减，食欲有所增进，血心管功能趋于稳定，因而允许体重下降远远超出了在一般血透情况下的最大值，回收后血浆白蛋白浓度均显著增加。     

Reciprocal changes in atrial natriuretic peptide levels and plasma renin activity during treatment of pulmonary embolism

We followed atrial natriuretic peptide (ANP) levels in 12 patients during anticoagulant treatment of pulmonary embolism. In each patient with this disorder ANP decreased during treatment. Concomitantly, plasma renin activity (PRA) markedly rose. The decrease in ANP was significantly related to the rise in PRA. No consistent changes in ANP or in PRA were observed in five patients with peripheral venous thrombosis receiving the same anticoagulant treatment. Plasma aldosterone levels did not change in either group.     

Effect of aging on circadian rhythm of atrial natriuretic peptide, plasma renin activity, and plasma aldosterone.

Atrial natriuretic peptide (ANP) shows a nychtohemeral fluctuation and an age-related trend. The aim of this study was to explore the circadian rhythm of ANP as a function of age. Circadian rhythms of plasma renin activity (PRA), aldosterone (PA), and cortisol (PC) were explored as well. Twenty clinically healthy subjects, 10 young (20-25 yrs) and 10 elderly (65-75 yrs), were investigated, while recumbent, after synchronization to light-dark regimen and meal timing. Blood samples for RIA tests were collected six times during the 24-hr span. The chronobiologic analysis in young subjects demonstrated a significant circadian rhythm for all the investigated variables with an acrophase-timing located at 16.48 for ANP, 4.44 for PRA, 5.32 for PA, and 7.12 for PC. In elderly subjects we documented an important increase of 24-hr mean plasma levels but not a statistically significant circadian rhythm for ANP, and a decrease in mean value of PRA which maintained, however, a significant periodic 24-hr oscillation in parallel with PA and PC. The results in young subjects reinforce the concept that ANP plays physiologically an inhibitory role on the phasic secretion of renin. The lack of the circadian rhythm for ANP along with the divergent changes in ANP and PRA 24-hr mean concentration of elderly subjects both suggest that ANP exerts with advancing age only a counterregulatory role on the tonic rather than the phasic release of renin.     

慢性心力衰竭患者外周血中血浆肾素活性和利钠肽水平的变化及卡维地洛对其影响

目的　观察慢性心力衰竭 (心衰 )患者外周血中血浆肾素活性 (PRA)、心钠肽 (ANP)及脑钠肽 (N BNP)水平的变化及卡维地洛对其影响。方法　 6 0例慢性心衰患者随机分为常规治疗组 (血管紧张素转换酶抑制 +利尿剂 +地高辛 )和卡维地洛组 (常治疗药物 +卡维地洛 ) ,随访 12w ,采用放射免疫法测定二组治疗前后和 30例健康体检者 (正常对照组 )外周血中PRA、ANP、及N BNP水平。同时使用核素心室显像测定心衰患者左心室射血分数 (LVEF)。结果　心衰患者外周血中PRA、ANP及N BNP水平较正常对照组显著升高 ,其中ANP及N BNP水平在卡维地洛治疗前与LVEF负相关 ,在卡维地洛治疗后与LVEF密切相关 ,但PRA水平与LVEF无关。治疗后卡维地洛组外周血中PRA、ANP及N BNP水平较常规治疗组下降更明显。结论　外周血中ANP及N BNP水平在慢性心衰的病理生理机制中起着重要作用 ,甚至在 β受体阻滞剂治疗后仍可用于指导心衰患者的治疗。β受体阻滞剂能抑制心衰患者神经内分泌的过度激活。     

Effects of repeated atrial natriuretic peptide bolus injections in cirrhotic patients with refractory ascites

The renal and hormonal effects of repeated atrial natriuretic peptide (ANP) boli (1 microgram/kg of body weight) were studied in eight cirrhotic patients with refractory ascites. Under basal conditions the patients showed a striking activation of the renin-angiotensin-aldosterone system (plasma renin activity 19.3 +/- 3.0 ng/ml.h, plasma aldosterone concentration 3.87 +/- 0.58 ng/ml) and a tenfold elevation in plasma ANP levels compared to healthy subjects (131.7, range 47.0-288.6, vs. 9.8, range 5.0-15.0, fmol/ml, p less than 0.001). The first ANP injection was followed by a remarkable increase in plasma ANP levels and by a slight increase in urinary cyclic guanosine-monophosphate excretion (from 1050.8 +/- 454.8 to 1446.6 +/- 822.2 pmol/min). A significant reduction of mean blood pressure (MBP) occurred 5 min after the first injection (from 86.7 +/- 7.2 to 79.9 +/- 5.8 mmHg, p less than 0.05), but values gradually returned to the baseline after 30 min. Heart rate (HR) increased 10 min after the first bolus injection (from 83.75 +/- 4.7 to 88.1 +/- 4.6 beats/min) and reached baseline values after 30 min. Similar behaviour of MBP and HR was observed after the second, third and fourth bolus injections. Urinary sodium excretion, urinary flow, glomerular filtration rate, plasma renin activity, and plasma aldosterone concentration did not show any significant modification during ANP administration, nor did these parameters change in the following 12-h recovery period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute effects of peritoneovenous shunting on plasma atrial natriuretic peptide in cirrhotic patients with massive refractory ascites

Plasma immunoreactive alpha-human atrial natriuretic peptide (ANP) was measured in six cirrhotic patients with massive refractory ascites, under strict metabolic conditions, while they were receiving a 20-meq sodium diet, both before and at two-hour intervals for eight hours following peritoneovenous shunting (PVS). The mean preoperative level of ANP was 75 +/- 18 pg/ml, which was found to be significantly higher than the normal range for this laboratory (8 to 24 pg/ml) (p less than 0.05). This value was also significantly higher than the value of 21 +/- 5 pg/ml (p less than 0.05) obtained in six patients with cirrhosis but without ascites. Following shunt insertion, an immediate natriuresis and diuresis were observed in five of the six cirrhotic patients with refractory ascites. In these five, right atrial pressure and ANP rose immediately, followed by a rise in the level of urinary cyclic guanosine monophosphate. The sixth subject had a delayed rise in right atrial pressure, and correspondingly the rise in ANP, the diuresis, and natriuresis were delayed. The changes in ANP following PVS were positively correlated with changes in right atrial pressure (p less than 0.05), urinary cyclic guanosine monophosphate (p less than 0.05), urinary sodium excretion (p less than 0.05), and urine volume (p less than 0.01). These results suggest that ANP may be important in mediating the acute response to PVS.     

心房颤动患者血浆心房钠尿肽与C型钠尿肽浓度的变化

目的观察心房颤动(简称房颤)患者血浆心房钠尿肽(ANP)和C型钠尿肽(CNP)水平的变化,及其与心脏结构改变的相关性,从而进一步分析ANP、CNP在房颤心房结构重构中的作用。方法入选左心功能正常的房颤患者及无房颤对照组。房颤患者又根据房颤持续时间不同分为阵发性房颤(Paf)组及持续性房颤(Peaf)组。采用酶联免疫吸附法检测血浆ANP和CNP水平,并采用超声心动图测量舒张期左房内径、左室内径、室间隔厚度及左室后壁厚度,并计算左室质量指数。结果入选对照组57例,和房颤组62例(其中Paf组35例,Peaf组27例)。年龄、性别等临床背景资料均无差异,具有可比性。房颤组的血浆ANP和CNP水平明显高于对照组[ANP:(728.1±336.9)pg/ml vs(524.6±165.3)pg/ml,P=0.000;CNP:(114.2±28.6)pg/ml vs(97.1±22.4)pg/ml,P=0.000],且与左房内径明显正相关(ANP:r=0.389,P=0.001;CNP:r=0.344,P=0.004)。此外,ANP与CNP之间呈明显的相关性(r=0.799,P=0.000),CNP与室间隔厚度(r=0.343,P=0.006)、左室后壁厚度(r=0.308,P=0.013)、左室质量指数(r=0.275,P=0.030)相关。结论 ANP和CNP与左房扩大明显相关,可能参与心脏重构的过程。     

Bactericidal and opsonic activity of ascitic fluid from cirrhotic and noncirrhotic patients

Cirrhotic patients with ascites are highly susceptible to spontaneous bacterial peritonitis. Patients with ascites due to causes other than cirrhosis very seldom develop peritonitis. The antibacterial activity of these ascitic fluids is not known. The present study was undertaken to evaluate the bactericidal and opsonic activity in ascitic fluid from patients with and without cirrhosis and in normal (nonascitic) peritoneal fluid. Normal peritoneal fluids of 20 control subjects and ascitic fluids of 22 patients with noncirrhotic ascites all had normal bactericidal activity. The bactericidal activity of ascitic fluid was diminished in all 25 patients with cirrhosis (P less than 0.00005 by Fisher's exact test). Similar results were found when opsonic activity was evaluated. Complement and immunoglobulin concentrations in cirrhotic ascites were significantly lower than those in the other two groups. The present study demonstrates that noncirrhotic ascitic fluid has antibacterial activity similar to normal peritoneal fluid, whereas cirrhotic ascitic fluid has a marked reduction of both bactericidal and opsonic activities. These defects may explain the high incidence of peritonitis in cirrhotic patients.     

Effects of licorice on plasma atrial natriuretic peptide in healthy volunteers

Ingestion of licorice, 100 g daily for 8 weeks, caused a rise in 81% in plasma atrial natriuretic peptide (ANP) concentration in 12 healthy subjects. Mean body weight increment (1.6 kg) correlated with the increase in plasma ANP (r = 0.59; P less than 0.01). The plasma concentrations of antidiuretic hormone, aldosterone, and plasma renin activity decreased. All these hormonal effects, reflecting retention of sodium and fluid volume, were probably due to the known mineralocorticoid properties of licorice. Blood pressure increased transiently and two subjects developed reversible hypertension. The rise in plasma ANP concentration during ingestion of licorice may be considered a physiological response to prevent fluid retention and development of hypertension.     

Variability of atrial natriuretic peptide plasma levels in ascitic cirrhotics: pathophysiological and clinical implications.

Ascitic cirrhotic patients are a heterogenous population with respect to factors that may affect plasma human atrial natriuretic peptide levels (such as degree of plasma volume and plasma levels of angiotensin II, vasopressin and norepinephrine). Thus the proven variability of plasma human atrial natriuretic peptide values in ascitic cirrhotic patients may be due also to the selection of patients, not only to the study conditions. The response to standardized stepped-care medical treatment of ascites makes it possible to characterize ascitic cirrhotic patients with different patterns of renal sodium excretion, intrarenal sodium handling, plasma renin activity, plasma aldosterone and thus, probably, effective circulating volume. Consequently, we evaluated human atrial natriuretic peptide plasma levels in controls (n = 23), in ascitic cirrhotic patients who underwent spontaneous diuresis (group A, n = 7) and in cirrhotic patients who required diuretic treatment (group B, n = 44). The last group was then divided into two subgroups. Subgroup B-R (n = 25) included patients who responded to spironolactone alone, whereas subgroup B-NR (n = 19) included patients who did not respond to 500 mg/day spironolactone. All patients were maintained on identical normocaloric restricted sodium intake (80 mEq/day) throughout the study. Ascitic cirrhotic patients, as a whole, had higher values of human atrial natriuretic peptide than did controls (70.8 +/- 46.6 pg/ml vs. 41.7 +/- 16.3 pg/ml, p < 0.025). No difference was found in human atrial natriuretic peptide/plasma renin activity between the two groups (87 +/- 160 pg/ng/hr vs. 44 +/- 73 pg/ng/hr, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma atrial natriuretic peptide, aldosterone, and plasma renin activity responses to gradual changes in dietary sodium intake

The present study examines the responses of plasma atrial natriuretic peptide (ANP), aldosterone and plasma renin activity to small alterations in dietary sodium intake. Six normotensive subjects were equilibrated on a low sodium intake of 10 mmol/day for 4 days. Dietary sodium intake was then increased gradually by 50 mmol/day to a maximum of 350 mmol/day over a 7 day period. With the gradual increase in sodium intake there were progressive increases in urinary sodium and cumulative sodium balance. These were associated with gradual increases in plasma ANP and reductions in both plasma aldosterone and plasma renin activity. During the study there were no significant changes in blood pressure, urinary potassium and creatinine clearance. This study demonstrates a marked sensitivity of the responses of both the ANP and the renin-aldosterone system to small changes in sodium intake and points to their importance in the renal adaptations to small alterations in dietary sodium intake.     

Rebound increase in plasma renin and vasopressin following graded infusions of atrial natriuretic peptide in man

The effects of graded infusions of atrial natriuretic peptide (ANP) on hemodynamics, renal function, plasma renin activity (PRA) and plasma arginine vasopressin (AVP) were investigated in a two part study in 6 volunteers. Three 30-min iv infusions of either saline control or ANP at graded rates of 4, 10 and 40 pmol kg-1 min-1 were given. ANP infusions were associated with a significant increase in sodium clearance from 1.08 +/- 0.21 to 2.83 +/- 0.50 ml/min, an increase in hematocrit and a net fluid loss. Plasma AVP remained constant during ANP infusions but increased significantly afterwards when plasma ANP concentrations were falling rapidly, and this was accompanied by marked antidiuresis. PRA fell by 23% during the saline control infusions and by 50% during ANP infusions. Following cessation of ANP infusions there was a significant rebound increase in PRA. No changes were observed in blood pressure, heart rate, glomerular filtration rate or renal plasma flow. These results suggest an interaction in man between ANP and the hormones renin and AVP.     

Effects of prolonged strenuous exercise on plasma levels of atrial natriuretic peptide and brain natriuretic peptide in healthy men

BACKGROUND: Now that marathon racing is growing in popularity, many thousands of enthusiastic athletes are participating in various ultramarathons all over the world each year. However, it remains controversial whether such a sport contributes to the promotion of health. The occurrence of transient cardiac dysfunction and irreversible myocardial injury has been reported in association with such exercise in healthy individuals. Brain natriuretic peptide (BNP) is a cardiac hormone, as is atrial natriuretic peptide (ANP), and its measurement has been widely used for clinical evaluation of cardiac dysfunction. However, little is known about the response of plasma BNP to prolonged strenuous exercise. We hypothesized that confirmation of minimal cardiac dysfunction or myocardial injury may be made by measurements of plasma BNP. METHODS: Levels of plasma ANP, BNP, catecholamines, blood lactate, and serum cardiac troponin T (cTnT) were determined before and after a 100-km ultramarathon in 10 healthy men to examine the effects of the exercise on levels of ANP and BNP and correlations between the natriuretic peptides and cTnT as a marker for myocardial damage. RESULTS: Whereas all variables significantly increased after the race, increased levels of ANP and BNP were most strongly correlated with increases in cTnT levels. The cTnT level after the race was greater than the upper reference limit in 9 of 10 men. CONCLUSIONS: Such exercise significantly increased ANP and BNP levels in healthy men, and the increases could be partially attributed to myocardial damage during the race.     

Low plasma concentrations of atrial natriuretic peptide in untreated hypothyroid patients

A group of patients with primary hypothyroidism has been studied, and it is reported that low serum levels of thyroid hormones are accompanied by low plasma atrial natriuretic peptide (ANP) concentrations. While the correlation between ANP and thyroid hormone levels is strong, no correlation was found between ANP and heart rate or arterial blood pressure. It is suggested that thyroid hormones directly stimulate the release of ANP from atrial cardiocytes.