Renin, aldosterone, and converting enzyme during exercise and acute hypoxia in humans

Milledge, J. S.; Catley, D. M.

doi:10.1152/jappl.1982.52.2.320

Cited by 58 publications

(36 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The role of hypoxia in activation of the renin-angiotensin system is controversial; whilst it potentiates exercise-induced activation of the system [31], it does not directly increase renin and angiotensin II at rest [32]. In the current study, no correlation has been identified between oxygen saturation and Pa,O 2 and renin or angiotensin II levels.…”

Section: Pathological Activation Of the Renin-angiotensin Systemcontrasting

confidence: 63%

Investigations on the renin-angiotensin system in acute severe asthma

Ramsay¹,

Dagg²,

McKay³

et al. 1997

Eur Respir J

View full text Add to dashboard Cite

The renin-angiotensin system is activated in acute severe asthma, although not in all asthmatics [1,2]. The mechanism of this activation is unclear, but recent evidence has shown elevation of renin and angiotensin II in response to nebulized and intravenous salbutamol [3,4]. A wide variation in plasma β 2 -agonist levels has been found in acute asthmatics in previous studies [5], and could, therefore, account for the variation in renin and angiotensin II levels.However, the degree of activation of the renin-angiotensin system following administration of β 2 -agonists is less than that seen in acute asthma, suggesting an additional mechanism. The generation of angiotensin II via an "alternative" pathway, through the action of inflammatory proteases [6] either circulating or locally within the airways, could occur in addition to the "classical" activation of the renin-angiotensin system. Endogenous catecholamines released during an acute attack of asthma [7] could stimulate adrenoceptors on juxtaglomerular cells in the kidney [8] resulting in renin release, and may act synergistically with systemically absorbed albuterol.Serum angiotensin-converting enzyme (ACE) levels vary between individuals and correlate with a genetic polymorphism of the ACE gene [9]. Homozygotes for the deletion polymorphism have a higher ACE activity [10], and, therefore, the capacity to produce greater levels of angiotensin II in response to activation of the renin-angiotensin system. Thus, serum ACE activity could contribute to the variation seen in angiotensin II levels in acute asth-ma.We hypothesize that activation of the renin-angiotensin system in acute severe asthma is partly due to high levels of circulating β 2 -agonists in some asthmatics, and that other factors, as suggested above, may also contribute, possibly with a synergistic effect. Thus, we have examined the associations between renin, angiotensin II and multiple factors during acute attacks of asthma, with particular emphasis on the mechanisms outlined above. Materials and methods PatientsForty adult asthmatic patients (26 females and 14 males; mean (SD) age 45 (17) yrs) were recruited into the study. All presented nonconsecutively at the accident and emergency department, with acute exacerbations of asthma unresponsive to their regular medication and requiring hospital admission for treatment. Admission parameters were measured with peak expiratory flow rate (PEFR) 35 (18) % predicted, oxygen saturation 94 (4) %, cardiac frequency 108 (16) beats·min -1 , systolic blood pressure 139.5Investigations on the renin-angiotensin system in acute severe asthma. S.G. Ramsay, K.D. Dagg, I.C. McKay, B.J. Lipworth, C. McSharry, N.C. Thomson. ERS Journals Ltd 1997. ABSTRACT: The renin-angiotensin system is activated in acute severe asthma. The precise mechanism of activation is at present unknown, but may involve, β 2 -agonists, catecholamines or proteases released in airway inflammation.This study aims to identify potential factors involved in the activation of the reninangiotensin ...

show abstract

Section: Pathological Activation Of the Renin-angiotensin Systemcontrasting

confidence: 63%

Investigations on the renin-angiotensin system in acute severe asthma

Ramsay¹,

Dagg²,

McKay³

et al. 1997

Eur Respir J

View full text Add to dashboard Cite

show abstract

“…The statistical similarity of circulating ACE activity between the two groups may be further evidence of this difference when considering that ACE levels may be influenced by mountaineering and exposure to altitude. [24][25][26] We found that the I allelic frequency and I dominant genotypic distribution (II & ID) of ACE I/D polymorphism were significantly over-represented in the Sherpas compared to the non-Sherpas at low altitude, providing insight into the genetic background of these two groups. The prevalence of the I allele was commonly associated with low ACE activity in both groups irrespective of either ethnicity or altitude of residence.…”

Section: Genotypic Distributions and Allelic Frequencies Of The Ace Imentioning

confidence: 99%

“…28 On the other hand, ACE activity was within +/-10% of normal sea-level values in high-altitude adapted mountaineers after 2-4 weeks at 6,300 m. 35 All of this suggests that maintaining physiologic low-altitude ACE activity at high altitude, as found in our study, may contribute to adaptive physiology by contributing to an adaptive respiratory response to hypoxia, 8,36, maintaining normal pulmonary artery pressures, 34 and contributing to sodium and fluid balance. 28 The level of circulating ACE is, however, significantly influenced by environmental stimuli such as hypoxia, 24 mountaineering and altitude. [25][26][27] ACE activity in individuals may vary by more than 100% over 6 months, 37 suggesting that environmental factors indeed cause marked fluctuations.…”

Section: Genotypic Distributions and Allelic Frequencies Of The Ace Imentioning

confidence: 99%

Adaptation to High Altitude in Sherpas: Association with the Insertion/Deletion Polymorphism in the Angiotensin-Converting Enzyme Gene

Droma

Hanaoka

Basnyat

et al. 2008

Wilderness & Environmental Medicine

View full text Add to dashboard Cite

Objective-Sherpas are well known for their physical strength at high altitudes. They adapt to high altitude so well that little acute or chronic mountain sickness has been documented in them. The possible genetic basis for this adaptation is, however, unclear. The objective of this study was to elucidate the genetic background underlying this characteristic among Sherpas with respect to the angiotension-converting enzyme (ACE) gene. Conclusions-These findings suggest that the over-represented I allele of the ACE gene in Sherpas might be one of the fundamental genetic factors responsible for maintaining physiological low-altitude ACE activity at high altitude, which may have an advantageous physiological role in adapting to a high-altitude environment. Methods-We2

show abstract

“…However, it seems likely that, using only six subjects in total, the study was significantly underpowered. Small sample sizes (as low as four) (Milledge and Catley 1982), and differences in exercise protocols may similarly account for other (false) negative findings. Thus, Aldigier et al (1993) studied only eight subjects exercising at incremental workloads separated by equal rest periods , and Miura et al (1994) six males at Fig.…”

Section: Ace Activitymentioning

confidence: 99%

“…However, it has been proposed that ACE becomes rate limiting in situations when levels of substrate Ang I increase. Exercise is associated with a rise in levels of plasma renin substrate (Metsarinne 1988), which is thought to be consumed, on account of the associated rise in renin activity (Fyhrquist et al 1983;Kosunen and Pakarinen 1976;Milledge and Catley 1982), to yield a rise in Ang I levels (Arvay et al 1982). It is also known that when levels of Ang I are artificially elevated through infusion, Ang II levels may become ACE genotypedependent (Brown et al 1998;Ueda et al 1995).…”

Section: Ang II Responsementioning

confidence: 99%

The serum angiotensin-converting enzyme and angiotensin II response to altered posture and acute exercise, and the influence of ACE genotype

Woods

Sanders

Jones

et al. 2004

European Journal of Applied Physiology

View full text Add to dashboard Cite

The deletion (D) rather than insertion (I) allele of the angiotensin-converting enzyme (ACE) gene is associated with greater ACE activity. We examined: (1) the influence of posture change (recumbent to seated) and acute exercise on serum ACE and angiotensin II (Ang II) activity; (2) the relationship between ACE and Ang II levels; and (3) the influence of ACE genotype on changes in ACE and Ang II levels with posture and exercise. Recreationally active young male Caucasians (10 each of II, ID and DD genotypes) rested for 35 min supine then 15 min upright, took 20 min bicycle ergometric exercise at 70% maximum oxygen uptake, then rested for 40 min. Samples were taken throughout for ACE activity and Ang II levels. Supine ACE levels were dependent upon ACE genotype [24.8 (5.7), 26.9 (4.5), 45.5 (6.4) nmol His-Leu ml(-1) min(-1); II, ID, DD, respectively; P<0.00005] and thereafter. ACE activity rose with assumption of a seated posture [from 32.4 (10.9) nmol His-Leu ml(-1) min(-1) to 35.0 (11.5) nmol His-Leu ml(-1) min(-1), P<0.00001], the absolute rise being independent of genotype [3.22 (1.92), 1.6 (1.6), 2.4 (2.3) nmol His-Leu ml(-1) min(-1); II, ID, DD; P=0.22], unlike percentage change [12.8 (6.8), 5.6 (5.5), 5.3 (5.0)%; II, ID, DD; P<0.01, and P=0.004 for II vs presence of the D allele]. A further genotype-independent rise occurred with exercise [+2.9 (3.7) units, P<0.0003]. An associated rise in Ang II levels [30.3 (15.9), or 2587.9 (489.76)%, P<0.00001] was independent of ACE genotype or activity. Upright posture increases ACE activity, and this may be influenced by ACE genotype. ACE activity and Ang II levels rise independently with exercise in a non-genotype-dependent fashion.

show abstract

Renin, aldosterone, and converting enzyme during exercise and acute hypoxia in humans

Cited by 58 publications

References 0 publications

Investigations on the renin-angiotensin system in acute severe asthma

Investigations on the renin-angiotensin system in acute severe asthma

Adaptation to High Altitude in Sherpas: Association with the Insertion/Deletion Polymorphism in the Angiotensin-Converting Enzyme Gene

The serum angiotensin-converting enzyme and angiotensin II response to altered posture and acute exercise, and the influence of ACE genotype

Contact Info

Product

Resources

About