Effect of physical exercise in hypobaric conditions on atrial natriuretic peptide secretion

Räsänen

Ultrasound in Obstet & Gyne

et al. 2007

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Objective To determine whether low cardiovascular profile (CVP) (28 (range, 24-35) weeks vs. 35 (range, 26-40) weeks, P < 0.01) and had lower CVP scores (4 (range,[2][3][4][5][6][5][6][7][8][9][10], P < 0.0001). All CVP subscale scores were lower (P < 0.01) in Group 1 than in Group 2 fetuses. Gestational age-adjusted hazard ratios (95% CIs) for adverse neonatal outcome were highest for cardiomegaly (13.9 (1.7-114.3), P = 0.014), monophasic atrioventricular filling pattern or holosystolic tricuspid regurgitation (9.5 (2.3-38.4

Section: Introductionmentioning

confidence: 99%

Human fetal cardiovascular profile score and neonatal outcome in intrauterine growth restriction

Räsänen

Ultrasound in Obstet & Gyne

et al. 2007

Self Cite

American Journal of Physiology-Endocrinology and Metabolism

“…After 40 min from the bolus injection of 1 g of human endothelin-1, the peptide levels had steadied to an apparent plateau of 0.402 Ϯ 0.108 nmol/l. As a comparison, the basal levels in human circulation are ϳ0.003-0.004 nmol/l (34). Therefore, caution is warranted when planning experiments in teleost fish with the use of constant infusion of endothelin because of the apparent risk of accumulation of the peptide in the circulation.…”

Section: Discussionmentioning

confidence: 99%

“…The assay procedure has been described in detail previously (28). Human endothelin-1 RIA were performed as described earlier (34).…”

Section: Expression and Purification Of Gst-nt-pro-scp Fusion Proteinmentioning

confidence: 99%

Pronatriuretic peptide is a sensitive marker of the endocrine function of teleost heart

Vierimaa¹,

Hirvinen²,

Tervonen³

et al. 2002

We recently characterized a novel heart-specific hormone from salmon (salmon cardiac peptide, sCP). We have now prepared a recombinant plasmid expressing the NH2-terminal fragment of pro-sCP (NT-pro-sCP) and used it to set up a specific RIA for the peptide. Because of the sensitivity of the assay and the high circulating levels, NTpro-sCP can be measured from as little as 2 l of serum. This enables repeated sampling from the same animal in different experimental setups. Mechanical load increased the release of NT-pro-sCP from isolated perfused salmon ventricle, in parallel with sCP. Bolus injection of human endothelin-1 (ET-1; 1 g) in the dorsal aorta of salmon resulted in an extensive increase of serum NT-pro-sCP (from 0.99 Ϯ 0.11 to 4.6 Ϯ 1.5 nmol/l). The response was abolished by pretreatment with a specific type A ET (ETA) receptor antagonist (BQ-123) but not with a type B ET receptor antagonist (BQ-788).The NT-pro-sCP levels had a good correlation with those of sCP (r 2 ϭ 0.75). Our results demonstrate the practical usefulness of circulating NT-pro-sCP as a marker of the endocrine function of salmon heart. They also suggest that ET-1 has an important role in regulating sCP release from teleost heart by an ETA receptor-mediated mechanism. natriuretic peptide; endothelin; recombinant protein; radioimmunoassay; study in vivo NATRIURETIC PEPTIDES are cardiac hormones with an important role in regulating cardiovascular and fluid homeostasis (2). The release of A-and B-type natriuretic peptides (ANP and BNP) from the heart is stimulated by increased load (11,14,18) and by various paracrine factors, such as endothelin-1 (3, 16, 30). They reduce the cardiac load by causing natriuresis, diuresis, and relaxation of the vascular smooth muscle and by inhibiting the renin-angiotensin-aldosterone system (21). Although blood volume expansion is an important stimulus for ANP secretion in mammals, in nonmammalian eel, ANP secretion has been reported to be more sensitive to osmotic than volemic stimuli. In this teleost, ANP causes excretion of Na ϩ , thereby promoting adaptation to seawater (9).In mammals, ANP is stored in the secretory granules of atrial myocytes as a large-molecular-weight prohormone (proANP). It is processed to low-molecularweight ANP during exocytosis (33), presumably by the membrane-bound serine protease corin (36). The products are the 28-amino-acid biologically active ANP and the inert 98-amino-acid NH 2 -terminal fragment NTproANP (8,31). The elimination of ANP from the circulation is very rapid, resulting in low and labile plasma concentrations. The half-life of rat NT-proANP in rat circulation has been reported to be eight times longer than that of ANP (32). Therefore, and because its plasma concentrations are much higher, the measurement of NT-proANP is preferred over that of ANP in the assessment of cardiac function, e.g., in patients with congestive heart failure (22). The same appears to apply for .We have recently cloned and characterized from salmon a novel peptide hormone, salmon cardiac pep...

Pharmacology & Toxicology

“…Under normal physiological circumstances, the major site of atrial natriuretic peptide synthesis is in the atria, but under pathophysiological conditions associated with chronic pressure or volume overload, ventricular atrial natriuretic peptide gene expression is also activated (Ruskoaho 1992). Plasma atrial natriuretic peptide has been shown to rise during acute dynamic exercise (Ruskoaho et al 1989;Schmidt et al 1990;Vuolteenaho et al 1992), but even a 55-week-long treadmill exercise does not increase Author for correspondence: Ilkka Pörsti, Medical School, University of Tampere, Department of Pharmacological Sciences, FIN-33014 Tampere, Finland (fax π358 3 215 6170, e-mail ilkka.porsti /uta.fi).plasma atrial natriuretic peptide at rest, or the gene expression of atrial natriuretic peptide in the ventricles of normotensive dogs (Mäntymaa et al 1994). In contrast, endurance training for 31 weeks elevates both the content and gene expression of atrial natriuretic peptide in the ventricles of spontaneously hypertensive rats (Mäntymaa et al 1994;Sallinen et al 1996).…”

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confidence: 99%

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confidence: 99%

Long‐Term Physical Exercise and Atrial Natriuretic Peptide in Obese Zucker Rats

Pörsti

Kähönen

et al. 2002

Endurance training increases natriuretic peptide synthesis in the hypertrophied myocardium of spontaneously hypertensive rats. We examined the effects of 22-week-long treadmill exercise on plasma and tissue atrial natriuretic peptide in Zucker rats, a model of genetic obesity and moderate hypertension without clear cardiac hypertrophy. The blood pressures of the animals were measured by the tail-cuff method, and plasma and tissue samples for the peptide determinations were taken at the end of the study. The training increased heart weight to body weight ratio, while atrial natriuretic peptide contents in the right and left atrium, ventricular tissue, and plasma did not change. The exercise prevented the elevation of blood pressure, which was observed in non-exercised obese Zucker rats, and also reduced blood pressure in the lean rats. In conclusion, these results suggest that in the absence of preceding myocardial hypertrophy, the long-term exercise-induced workload is not deleterious to the heart in experimental obesity, since no changes in plasma and tissue atrial natriuretic peptide were detected.The prevalence of hypertension is high among overweight persons (Landsberg 1992), and physical activity is recommended as a non-pharmacological measure for the treatment of hypertension and obesity (World Hypertension League 1991). The Zucker fatty rat is a well-established model of genetic obesity with autosomal recessive homozygous inheritance (fa/fa), the heterozygous and missing fa gene (Fa/?) producing the corresponding slender control strain, the lean Zucker rat (Argilès 1989). The fatty mutation is characterized by insulin resistance, hyperinsulinaemia, glucose intolerance, hyperlipidaemia (Argilès 1989), and often by the development of moderate hypertension (Kurtz et al. 1989;Baylis et al. 1991;Zeigler & Patel 1991;Kasiske et al. 1992). However, the obese Zucker rat does not show clear left ventricular hypertrophy (Cox & Kikta 1992).The myocardium adapts to increased workload by muscle cell hypertrophy, molecular changes in contractile proteins, and increased synthesis of atrial natriuretic peptide (Ruskoaho 1992). Under normal physiological circumstances, the major site of atrial natriuretic peptide synthesis is in the atria, but under pathophysiological conditions associated with chronic pressure or volume overload, ventricular atrial natriuretic peptide gene expression is also activated (Ruskoaho 1992). Plasma atrial natriuretic peptide has been shown to rise during acute dynamic exercise (Ruskoaho et al. 1989;Schmidt et al. 1990;Vuolteenaho et al. 1992), but even a 55-week-long treadmill exercise does not increase Author for correspondence: Ilkka Pörsti, Medical School, University of Tampere, Department of Pharmacological Sciences, FIN-33014 Tampere, Finland (fax π358 3 215 6170, e-mail ilkka.porsti /uta.fi).plasma atrial natriuretic peptide at rest, or the gene expression of atrial natriuretic peptide in the ventricles of normotensive dogs (Mäntymaa et al. 1994). In contrast, endurance training...