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Biomedical subjects

H G Predel

Publications and source records attributed to H G Predel.

At least 19 recordsLinked to original sources
PubMed2002

[An exercise program for the hypertensive patient. Leaving hypertension behind].

Today, regular exercise is considered an important therapeutic principle in arterial hypertension. Apart from weight reduction, the positive effects of sports (moderately practiced) include a reduction in peripheral resistance, improvement of endothelial dysfunction, and an increase in insulin sensitivity of the skeletal muscles. Training programs should be tailored to the physical and mental status of the patient, in particular to the severity of the hypertension, where indicated, with consideration being given to the hypertensive drugs used. In the case of marked hypertension or already existing secondary complications, training should be started only when the patient's blood pressure has been brought under pharmacological control. Ideally, training should be applied as 20-60 minute sessions at least twice weekly, with exercise keeping within aerobic capacity.

Antihypertensive Agents↗
PubMed2001

Integrated effects of the vasodilating beta-blocker nebivolol on exercise performance, energy metabolism, cardiovascular and neurohormonal parameters in physically active patients with arterial hypertension.

OBJECTIVE: The present study was designed to investigate the integrated effects of the beta-1-selective blocker with vasodilator properties, nebivolol, on systemic haemodynamics, neurohormones and energy metabolism as well as oxygen uptake and exercise performance in physically active patients with moderate essential hypertension (EH). DESIGN AND METHODS: Eighteen physically active patients with moderate EH were included: age: 46.9 +/- 2.38 years, weight: 83.9 +/- 2.81 kg, blood pressure (BP): 155.8 +/- 3.90/102.5 +/- 1.86 mm Hg, heart rate: 73.6 +/- 2.98 min(-1). After a 14-day wash-out period a bicycle spiroergometry until exhaustion (WHO) was performed followed by a 45-min submaximal exercise test on the 2.5 mmol/l lactate-level 48 h later. Before, during and directly after exercise testing blood samples were taken. An identical protocol was repeated after a 6-week treatment period with 5 mg nebivolol/day. RESULTS: Nebivolol treatment resulted in a significant (P < 0.01) decrease in systolic and diastolic BP and heart rate at rest and during maximal and submaximal exercise. Maximal physical work performance, blood lactate and rel. oxygen uptake (rel. VO(2)) before and after nebivolol treatment at rest and during maximal and submaximal exercise remained unaltered. Free fatty acid, free glycerol, plasma catecholamines, beta-endorphines and atrial natriuretic peptide (ANP) increased before and after treatment during maximal and submaximal exercise but remained unaltered by nebivolol treatment. In contrast, plasma ANP levels at rest were significantly higher in the presence of nebivolol, endothelin-1 levels were unchanged. CONCLUSIONS: Nebivolol was effective in the control of BP at rest and during exercise in patients with EH. Furthermore, nebivolol did not negatively affect lipid and carbohydrate metabolism and substrate flow. The explanation for the effects on ANP at rest remain elusive. This pharmacodynamic profile of nebivolol is potentially suitable in physically active patients with EH.

Adrenergic beta-Antagonists↗
PubMed2001

ACE and angiotensinogen gene genotypes and left ventricular mass in athletes.

BACKGROUND: Genetic factors may be important in modifying heart size due to long-term athletic training. The significance of polymorphisms of genes of the renin-angiotensin system in myocardial mass in a population of athletes participating in different disciplines is not known. METHODS: The angiotensin I-converting enzyme gene insertion/deletion (I/D) polymorphism, angiotensinogen gene M235T polymorphism and angiotensin II type 1 receptor gene A1166C polymorphism were determined in 83 male Caucasian endurance athletes and associated with left ventricular mass. RESULTS: No association with left ventricular mass was found for the polymorphisms of angiotensin I-converting enzyme gene I/D, angiotensinogen gene M235T and angiotensin II type 1 gene A1166C when studied separately. However, combined analysis of the angiotensin I-converting enzyme gene I/D polymorphism and angiotensinogen gene M235T polymorphism genotypes suggested an association with left ventricular mass (g m(-2)) (P = 0.023). Athletes with the angiotensin I-converting enzyme gene DD/angiotensinogen gene TT genotype combination had greater left ventricular mass compared with all other genotype combinations (179.8 +/- 26.1 g m(-2) vs. 145.2 +/- 27.3 g m(-2), P = 0.003). CONCLUSIONS: These results suggest an association of combined angiotensin I-converting enzyme gene I/D polymorphism genotypes, and angiotensinogen gene M235T polymorphism genotypes with left ventricular hypertrophy due to long-term athletic training. A synergistic effect of angiotensin I-converting enzyme gene DD genotype and angiotensinogen gene TT genotype on left ventricular mass in endurance athletes appears to occur.

Adolescent↗
PubMed2000

[Phase II ambulatory cardiac rehabilitation (Cologne model). 3 year results after conclusion of the intervention].

UNLABELLED: BASELINE: Of a total of 101 patients with CAD who participated in an ambulatory cardiac rehabilitation program (ACR) ("Cologne model") between 1992 and 1994, 76 (75.2%) were examined 36 months after concluding ACR. RESULTS: The significant improvement in exercise tolerance from 118.4 +/- 30.1 to 131.9 +/- 34.1 W achieved with the ACR was maintained at the 3-year examination. ACR also significantly decreased plasma cholesterol levels from 228.9 +/- 48.3 to 211.7 +/- 37.0 mg%; 3 years after ACR the corresponding figures were 219.1 +/- 39.3 mg%. In the high-risk group the significant reduction in plasma cholesterol levels from 265 +/- 43.6 to 231.9 +/- 35.4 mg% observed immediately after ACR was maintained over the three-year period (234.6 +/- 37.7 mg%). Similar patterns were observed for other parameters of lipid metabolism. Before the cardiac event 63.2% of the patients smoked; at the 3-year examination the percentage was 30.3%. Before ACR, 73.7% of the patients were gainfully employed. Within the first 6 months after ACR, 71.4% returned to work, and this percentage increased to 73.2% after one year. Three years later, 64.3% were still working. DISCUSSION: The results demonstrate that the lifestyle changes achieved with 4-weeks of ACR may, at least in part, be maintained over a period of 36 months.

Adult↗
PubMed1999

[Ambulatory cardiac phase II rehabilitation--"the Cologne model"--including 3-year-outcome after termination of rehabilitation].

From January 1992 until December 1994 the Cologne model of ambulant cardiac rehabilitation (ACR) in the greater area of Cologne, Germany, was performed and is still in progress. In Germany until 1992 the cardiac rehabilitation was exclusively performed stationary. The objective of the "Cologne model" was to evaluate, whether the transfer of the stationary cardiac rehabilitation programs into the ambulatory setting is achievable without deficits in efficiency, safety and overall quality. The results obtained are intended to serve for standardization and quality control of future ambulatory cardiac rehabilitation programs in Germany. From 1992 to 1994 108 patients (94 men, 14 women; 52.3 +/- 8.0 years old) with coronary artery disease (CAD) which were compatible with the criteria of the "Cologne model" (Table 1) participated in the 4-week ACR. The indications for inclusion into the ACR were in 74 cases a myocardial infarction (MI), in 34 cases CAD without MI, but with PTCA/stent-procedure (Table 3). Seven patients discontinued the ACR prematurely, 2 patients because of cardiovascular reasons. Reasons for the preference of the ambulatory over a stationary cardiac rehabilitation program were in 40.6% of the patients refusal of "hospital ambience", in 43.6% familiar or in 12.9% professional reasons. During the 4-week ACR patients participated in a mean of 72.9 +/- 6.7 hours of therapy (Table 4). As a result of the ACR exercise tolerance increased highly significantly (**) from 116.4 +/- 28.8 to 129.9 +/- 34.6 watt). This improvement was maintained at the 1- and 3-year control (128.7 +/- 35.8**) examinations (Tables 5 and 7). One year after ACR 77% of the patients stated to be physically active in ambulatory heart groups (AHG) (27.6%) or on their own (49.4%). Three years after ACR the rate of regularly physically active patients still was 59.2%. Furthermore, as a result of ACR the dietary behavior was changed significantly. There was a reduction in the consumption of lipids by 20.8%, saturated fatty acids by 30.7% and of cholesterol by 30.5%. The plasma concentrations of cholesterol decreased from 231 +/- 49.8 to 213.2 +/- 35.9 mg%**. Six (and 12) months after ACR they increased again to 225.6 +/- 39.4 mg%. Three years after ACR the mean cholesterol level was 219.1 +/- 39.3 mg%. In the high risk group (cholesterol at the initial visit > 220 mg%) cholesterol levels were reduced from 266 +/- 44 to 232 +/- 31.9 mg%**. Six and 12 months after ACR they were 239.7 +/- 35.8 mg% and 245.8 +/- 32.6 mg%, respectively, (Tables 6 and 7) and still significantly lower than before ACR, though only 19% of the patients were treated with lipid lowering agents. Three years after ACR cholesterol were 234.6 +/- 37.7 mg%** in the high-risk group. 34.2% of the patients received lipid lowering agents. Mean body weight remained unaltered over the 3-year period. Smoking behavior was not altered significantly during the 4-week ACR. However, before the cardiovascular event 67.3% of the patients had smoked cigarettes. At the beginning and at the end of ACR 20.8% of the patients still smoked. During the ACR the number of smoked cigarettes was reduced significantly from 32.4 +/- 15.2 to 6.9 +/- 5.2 cigarettes per day. One year after ACR 23% of the patients were smokers, 3 years after ACR the percentage of smokers increased to 30.3%. Before ACR 73.3% of the patients were still working. During the first 6 months after ACR 68.2% returned to work and the percentage increased to 73% in the following 6 months. The results demonstrate that it is achievable to transfer the contents of the established stationary cardiac rehabilitation programs into the ambulatory setting without loss of efficiency, safety and overall quality. It is further confirmed, that it is necessary to continuously evaluate the results of the cardiac rehabilitation program on a long-term basis. (ABSTRACT TRUNCATED)

Adult↗
PubMed1999

[Clinical follow-up 6 months after ambulatory/partial inpatient after-care rehabilitation. Further results of the Cologne model of ambulatory cardiac phase II rehabilitation].

Three hundred and thirty patients with coronary artery disease (CAD) (288 men, 42 women, age of 55.5 +/- 10.0 years) participated in a 4-week ambulatory cardiac rehabilitation program (ACR) (Table 1). The cardiovascular indication for ACR was in 229 cases a myocardial infarction. In 101 patients a CAD with invasive revascularization but without a history of MI was present. In 92 patients with myocardial infarction additionally an invasive revascularization was performed. Eighty-three patients were included after a CABG-procedure (Tables 2 to 5). Six months after the ACR 290 (87.9%) patients presented for clinical reevaluation. In 235 (81.0%) of the 290 examined patients the cardiovascular diagnosis was unaltered. In the first 6 months after ACR in 76 (26.2%) patients a coronarography was performed, in 44 patients a restenosis was diagnosed. In 36 patients an additional invasive procedure (in 28 patients a PTCA, in 5 patients with additional stent-implantation, in 1 case with rotablation, in 8 patients CABG) was performed. In 1 patients a pace-maker was implanted. Since the ACR 1 patient experienced a myocardial infarction and 2 a recurrent myocardial infarction. In 1 patient myocardial fibrillation occurred. Totally, 70 patients (24.1%) required stationary-hospital treatment during the first 6 months after ACR (Table 6). In 11 cases an acute admission to hospital treatment because of cardiovascular reasons was documented. The majority of the hospital admission was elective, because of diagnostic or therapeutic procedures. In 6 patients a CABG-surgery was performed. In approximately 80% of the patients the cardiovascular status was stable during the first 6 months after ACR. Though 24.1% of the patients required stationary hospital treatment, the majority of the admissions was elective of interest, there was a high rate of hospital admissions in the PTCA-group in combination with recoronarographies and revascularization because of early reocclusion.

Adult↗
PubMed1999

[Improvement of physical performance and aerobic capacity mediated by a novel 4--week ambulatory cardiac rehabilitation program].

During a 4-week ambulatory cardiac rehabilitation program, 262 patients with coronary artery disease (CAD), 235 men and 27 women, 53.6 +/- 10.2 years, performed 30.5 +/- 2.9 exercise units. Before and after the rehabilitation program exercise, capacity was assessed by bicycle ergometry. There was a significant (p < 0.001) increase in the maximum exercise capacity at the end of the program (105.3 +/- 32.3 vs. 121.9 +/- 37.3 W). Physical work capacity on the 2.0 mmol lactate level improved (p < 0.001) from 72.2 +/- 23.5 to 86.4 +/- 25.8 W, on the 2.5 mmol/l level (p < 0.001) from 83.5 +/- 23.2 to 97.4 +/- 26.4 W, and on the 3.0 mmol/l level (p < 0.001) from 93.1 +/- 23.0 to 106.6 +/- 26.1 W. Despite enhanced performance, heart rate remained unaltered on the 2.0, 2.5, and 3.0 mmol/l lactate level. Furthermore, ergometric performance on predefined heart rate levels was significantly (p < 0.001) increased: 85/min: from 56.0 +/- 24.1 to 65.8 +/- 24.5 W, 90/min: from 62.0 +/- 27.3 to 71.2 +/- 26 W; 95/min: from 67.2 +/- 26.4 to 77.5 +/- 27.6 W; 100/min: from 71.1 +/- 29.6 to 80.6 +/- 28.1 W; 105/min: from 69.8 +/- 26.2 to 81.9 +/- 28.2 W and 110/min: from 73.6 +/- 28.9 to 90.4 +/- 29.4 W. The results demonstrate that physical performance in patients with CAD was improved by our novel ambulatory cardiac rehabilitation program. This improvement included an increase in maximum as well as endurance work capacity; furthermore, this increase was accompanied by a decrease in resting and exercise heart rates. The results demonstrate an absolute increase of physical performance, more importantly an increase of physical performance at defined lactate levels in the presence of unchanged heart rates mediated by the rehabilitation program. Thus, this increase was independent of motivational factors in the patients and/or the investigators during the re-exercise test. On the contrary, our data demonstrate that it is based on an improvement of aerobic endurance capacity associated with a therapeutically beneficial significant decrease of heart rate for a defined workload. The effects were independent of pharmacological influences (e.g., beta-receptor antagonists). These findings are of clinical importance with respect to reduction of myocardial oxygen consumption in patients with CAD.

Coronary Disease↗
PubMed1995

The exercise-induced increase in plasma levels of endothelin-1 is enhanced in patients with atherosclerotic coronary artery disease. Modulation by pentaerithrityltetranitrat (PETN).

BACKGROUND AND OBJECTIVE: Previous studies have suggested that endothelin (ET)-1 with its marked vasoconstrictive potency may play a role in the induction of coronary artery spasms. Furthermore, it was demonstrated using in-vitro vessel preparations that the secretion of ET-1 by the vascular endothelium is enhanced in the presence of atherosclerotic alterations. The objective of the present study was to investigate a) the effects of ergometric exercise on ET-1 plasma concentrations in 10 patients with coronary artery disease (CAD) as compared to an age and sex matched control group and b) the modulatory role of the orally administered organic nitrate, pentaerithrityltetranitrat (PETN), in patients with CAD. PATIENTS AND METHODS: 10 male patients with CAD confirmed by coronarography and 10 male healthy controls underwent a bicycle ergometry according to the WHO-standards upt to 125 watts. Venous blood samples for determination of ANP and ET-1 plasma concentrations were drawn in supine position directly before and 5 min after ergometric exercise. Subsequently, patients were randomized and treated for 3 days in a crossover design either with placebo or PETN (150 mg b.i.d.). RESULTS: Basal plasma levels of ET-1 were 6.1 +/- 0.7 pg/ml (patients) and 5.5 +/- 0.6 pg/ml (controls), resp. (n.s.). After ergometric exercise ET-1 plasma concentrations rose significantly (7.3 +/- 0.9 pg/ml; p < 0.05) in the placebo-treated patient group, whereas they remained constant (5.5 +/- 0.7 pg/ml) in the PETN-treated patient group. Blood pressure and heart rate were not modified by the PETN-treatment. ET-1 plasma levels remained unaffected by ergometric exercise in controls. DISCUSSION: In contrast to healthy controls ergometric exercise induced an increase in ET-1 plasma concentrations in patients with CAD that may be potentially harmful by promoting coronary vasospasms. The almost complete blunting of the ET-1-increase in the presence of PETN-therapy may result from local-hemodynamic effects of the organic nitrate; it may be hypothesized that the nitrate-induced rise in local NO-concentrations counteracts ET-secretion. The findings of the present study are in accordance with the beneficial clinical effects of organic nitrates in patients with CAD.

Administration, Oral↗
PubMed1995

Exercise increases endothelin-1 plasma concentrations in patients with coronary artery disease: modulatory role of LDL cholesterol and of pentaerithrityltetranitrate.

Previous studies suggest that ET-1 plays a role in induction of coronary artery disease (CAD). It was shown that secretion of endothelin-1 (ET-1) by the vascular endothelium is enhanced in atherosclerotic alterations and may be antagonized by EDRF. The objective of the present study was to investigate the effects of ergometric exercise on plasma ET-1 concentrations, and the potential modulatory role of LDL cholesterol, and the effects of an orally administered nitrate, PETN, in patients with CAD. Ten men with CAD and 10 healthy men underwent bicycle ergometry according to the WHO-standards. Venous blood samples for determination of ET-1 concentrations were drawn directly before and 5 min after ergometric exercise. Patients were randomized and treated for 72 h in a crossover design either with placebo or pentaerithrityltetranitrate (PETN). After 72 h the identical ergometric protocol was repeated. Basal plasma levels of ET-1 were 6.1 +/- 0.7 pg/ml (patients) and 5.5 +/- 0.6 pg/ml (controls) (n.s.). After ergometric exercise ET-1 plasma concentrations rose significantly (7.3 +/- 0.9 pg/ml; p < 0.05) in the patient group under placebo treatment, whereas they remained constant (5.5 +/- 0.7 pg/ml) with PETN treatment. ET-1 levels remained unaffected by ergometric exercise in healthy controls. Mean LDL cholesterol plasma levels in patients with CAD were 156 +/- 8 mg% and 152 +/- 7 mg% in healthy controls. In the patient group there was a significant (p < 0.002) positive correlation between the exercise-induced increase in ET-1 and the LDL cholesterol plasma concentrations (r = 0.85). Blood pressure and heart rate were not modified by PETN treatment. In patients with CAD bicycle ergometry induced an increase in ET-1 plasma concentrations. The positive correlation with the LDL cholesterol plasma levels indicates that LDL cholesterol is involved in regulation of ET-1 secretion in vivo. PETN therapy completely abolished the exercise-induced increase in ET-1 plasma levels. This may result from local hemodynamic effects of the nitrate; hypothetically a nitrate-induced rise in the local NO concentrations can be considered. The clinical implications of these findings remain elusive. However, the findings of the present study are in accordance with the beneficial clinical effects of nitrates in patients with CAD.

Cholesterol, LDL↗
PubMed1994

ACE inhibition and physical exercise: studies on physical work capacity, energy metabolism, and maximum oxygen uptake in well-trained, healthy subjects.

We investigated the effects of the angiotensin-converting enzyme (ACE) inhibitor trandolapril (2 mg/o.d.) on the physical work capacity (PWC), the received perception of exertion (RPE), as well as parameters determining physical performance (i.e., energy metabolism, lactate production, and oxygen uptake) in well-trained, healthy subjects. Twenty male sports students underwent a bicycle spiroergometry until exhaustion to determine maximum work load, maximum oxygen uptake, lactate threshold, and parameters of energy metabolism. The identical protocol was repeated after a 14-day treatment period with 2 mg of trandolapril o.d. or placebo. Treatment with the ACE inhibitor did not significantly alter maximum PWC, RPE, 4.0 mmol/L lactate threshold, heart rate, maximum oxygen uptake, plasma levels of total cholesterol, triglycerides, free fatty acids, glucose, insulin, cortisol, and human growth hormone. In the presence of the ACE inhibitor, the exercise-induced increase in systolic blood pressure was moderately (n.s.) blunted (204 +/- 7 versus 192 +/- 7 mm Hg). Treatment with the ACE inhibitor did not impair physical performance and RPE. This favorable profile of action was accompanied by no alterations in maximum oxygen uptake and parameters of energy metabolism at all levels of exercise intensity. Therefore, it may be concluded that antihypertensive treatment with an ACE inhibitor should be primarily considered in physically active patients.

Adult↗
PubMed1994

Lisinopril versus slow release nifedipine in patients with essential hypertension: a multicentre study.

The present study was performed to investigate the efficacy and safety of the angiotensin converting enzyme (ACE) inhibitor lisinopril compared with those of the calcium channel blocker nifedipine in 293 patients with mild to moderate essential hypertension (supine diastolic blood pressure (DBP) 95-115 mmHg) in a multicentre, randomised, double-blind parallel group study after a two week single-blind placebo run-in period. Thus, the haemodynamic effects as well as side-effects during antihypertensive treatment were examined in 146 patients receiving lisinopril (20 mg once daily) and in 147 patients receiving slow release nifedipine (20 mg twice daily) who entered the six weeks' treatment period. From the analysis of efficacy one patient from the lisinopril and two patients from the nifedipine groups were excluded because their supine DBP after run-in was < 95 mmHg. Adverse reactions, mostly transient during the initial treatment period, and withdrawals occurred in six (4.1%) and three (2.1%) patients of the lisinopril group and in 12 (8.2%; NS) and three (2.0%) patients of the nifedipine group, respectively. After the six weeks' treatment period the lisinopril group showed 19 nonresponders (supine DBP > or = 95 mmHg) of the remaining 142 patients and the nifedipine group revealed 20 nonresponders of the remaining 142 patients. Initial supine and standing heart rates were similar in both groups. Supine heart rate fell significantly in the lisinopril group, whereas standing heart rate in this group and supine and standing heart rates in the nifedipine group did not change significantly with treatment. Thus, lisinopril proved to be as effective and safe as nifedipine with responder rates of 86.6% and 85.9%, respectively.

Blood Cell Count↗
PubMed1992

Implications of pulsatile stretch on growth of saphenous vein and mammary artery smooth muscle.

Internal mammary artery (IMA) coronary bypass grafts have a higher patency than saphenous vein (SV) grafts. Intimal hyperplasia and occlusion of venous grafts result from smooth muscle proliferation. Mechanical factors, such as pulsatile stretch, are potential mediators of this process. Smooth muscle cells from IMA and SV were cultured on deformable membranes and exposed to pulsatile stretch (60 cycles/min). This stimulus increased 3H-thymidine incorporation into venous (a two-fold increase) but not arterial smooth muscle cells after 24 h. Smooth muscle cell numbers from SV, but not IMA, were increased (p less than 0.05) after 6 days of stretch. Thus, pulsatile stretch stimulates smooth muscle cell proliferation in SV, but not IMA, and may contribute to venous bypass graft disease.

Cell Division↗
PubMed1992

Intranasal application of atrial natriuretic peptide and 1-deamino-d-arginine vasopressin in healthy volunteers. Hemodynamic, hormonal, and renal excretory effects.

In the present study we investigated the effects of an intranasal administration of 25 micrograms alpha-human atrial natriuretic peptide (alpha-hANP) dissolved in 0.2 mL 0.9% saline on renal excretory function, blood pressure (BP), heart rate (HR), and also its interaction with the renal effects of 20 micrograms deamino-d-arginine vasopressin (d-DAVP) in 10 healthy volunteers. After two 30-min control periods plasma concentrations of ANP and cGMP rose significantly from 14.8 +/- 1.8 pmol/L and 5.9 +/- 0.3 pmol/mL to 23.3 +/- 2.3 pmol/L and 6.6 +/- 0.4 pmol/mL (P less than .05), respectively within 30 min after ANP administration. The levels returned to basal values after 60 min. Urinary cGMP excretion initially rose from 17.9 +/- 3.6 to 46.8 +/- 3.7 pmol/30 min and then returned to control values, whereas plasma renin activity and plasma aldosterone concentration decreased significantly after 30 and 60 min (P less than .05). Systolic and diastolic BP declined slightly by 8% and 7%, respectively, while HR remained unaltered. Urine flow rate and sodium excretion increased by 321% and 190%, respectively (P less than .05). These changes were also significant when data were compared with a time-matched placebo study performed on the preceding day with intranasal administration of 0.2 mL 0.9% saline alone. After 48 h the protocol was repeated but 20 micrograms d-DAVP was administered intranasally 120 min before an intranasal application of 25 micrograms alpha-hANP. Within 120 min d-DAVP had reduced urine flow by approximately 50% (P less than .05), while sodium excretion remained unaltered.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1991

Effects of atrial natriuretic peptide on systemic and renal hemodynamics and renal excretory function in patients with chronic renal failure.

We examined the effects of 60 min alpha-hANP infusion (24 ng/min/kg) on glomerular filtration rate (GFR), renal blood flow (RBF), cardiac index (CI) and blood pressure (BP) in 8 patients with chronic renal failure (CRF) with GFR ranging from 18 to 80 ml/min/1.73 m2 and in 8 control (C) subjects with normal renal function. Basal plasma levels of ANP and cGMP were elevated in CRF (ANP: 60.6 +/- 9.1 vs 13.6 +/- 1.9 pmol/l, p less than 0.05; cGMP: 14.3 +/- 2.9 vs 6.6 +/- 1.1 pmol/ml, p less than 0.05). During ANP infusion, peak levels of cGMP were higher in CRF than in C (27.5 +/- 3.2 vs. 17.3 +/- 1.3 pmol/ml, p less than 0.05). During ANP infusion, GFR increased in CRF by 70.7 +/- 4.2% from 34.5 +/- 6.8 to 57.4 +/- 9.9 ml/min/1.73 m2 (p less than 0.001) as compared to 16.2 +/- 1.4% in C (p less than 0.001 vs CRF). RBF increased in CRF by 43.6 +/- 6.4% and in C by 3.1 +/- 1.2% (p less than 0.01). Basal urinary sodium excretion (UNaV) was slightly lower in CRF than in C but rose to the same level in both groups during ANP infusion. In CRF, as opposed to C, UNaV remained elevated above baseline after the end of the infusion. The effect of ANP on fractional sodium excretion (FENa), however, was more pronounced in C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Endogenous natriuretic and ouabain-like factors. Their roles in body fluid volume and blood pressure regulation.

An endogenous ouabain-like sodium pump inhibitor was demonstrated originally in serum or plasma of acutely extracellular fluid volume (ECFV) expanded animals and humans. Since then numerous studies have confirmed the presence of ouabain-like factor(s) (OLF) in blood, urine, cerebrospinal fluid, and various tissues including the heart and hypothalamus. Some of these OLFs represent well-known endogenous compounds, eg, free unsaturated fatty acids, which in vitro exhibit inhibition of transepithelial sodium transport, direct inhibition of the Na-K-ATPase enzyme, displacement of 3H-ouabain from its membrane receptor, and crossreaction with a digoxin antibody. Small molecular weight (MW) OLFs of yet unknown peptidic or nonpeptidic nature, which may be of hypothalamic origin, were also detected in various animal models of hypertension and in hypertensive patients. They may play a pathophysiological role especially in salt- and volume-dependent forms of hypertension. Our results show that OLFs increase basal and vasopressin-stimulated intracellular Ca2+ release in rat vascular smooth muscle cells in culture and in human platelets similar to the newly discovered endothelin. In addition, a natriuretic factor (natriuretic hormone) was detected by bioassay in plasma and urine, whose activity changes in parallel with sodium intake. We found that this natriuretic factor is associated with small peptides with a MW of less than 1,000. It is, however, unlikely that the two biological properties, ie, the ouabain-like and natriuretic activities, reside in a single compound. A number of circulating OLFs is certainly not identical with a humoral natriuretic factor. Nevertheless, there is increasing evidence for multiple interactions between OLF and the atrial natriuretic peptide (ANP).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗