Ouabain-like Factor Quantification in Mammalian Tissues and Plasma

Ferrandi, Mara; Manunta, Paolo; Balzan, Silvana; Hamlyn, John M.; Bianchi, Giuseppe; Ferrari, Paolo

doi:10.1161/01.hyp.30.4.886

Cited by 116 publications

(102 citation statements)

References 30 publications

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“…Elevated EO levels were observed in about 40% of patients with untreated essential hypertension (97) in patients with primary aldosteronism (97) and in those with ACTHinduced hypertension (32,33). Elevated EO levels were also observed in rodents with DOCA-salt hypertension (41,43), ACTH-hypertension (20, 20a, 115), reduced renal mass hypertension (108), and in salt-sensitive Milan strain rats on a high-salt diet (22,23). Indeed, a critical corollary to these reports is the evidence that prolonged administration of ouabain, itself (a Strophanthus steroid), but not digoxin or digitoxin (Digitalis steroids), elevates BP in normal rats and mice (19,60,72,74,75,116).…”

Section: Endogenous Ouabain and Other Endogenous Cardiotonic Steroidsmentioning

confidence: 99%

How does salt retention raise blood pressure?

Blaustein¹,

Zhang²,

Ling³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

129

121

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A critical question in hypertension research is: How is long-term blood pressure controlled? Excessive NaCl ingestion or NaCl retention by the kidneys and the consequent tendency toward plasma volume expansion lead to hypertension. Nevertheless, the precise mechanisms linking salt to high blood pressure are unresolved. The discovery of endogenous ouabain, an adrenocortical hormone, provided an important clue. Ouabain, a selective Na ϩ pump inhibitor, has cardiotonic and vasotonic effects. Plasma endogenous ouabain levels are significantly elevated in Ϸ40% of patients with essential hypertension and in animals with several forms of salt-dependent hypertension. Also, prolonged ouabain administration induces hypertension in rodents. Mice with mutant Na ϩ pumps or Na/Ca exchangers (NCX) and studies with a ouabain antagonist and an NCX blocker are revealing the missing molecular mechanisms. These data demonstrate that ␣ 2 Na ϩ pumps and NCX1 participate in long-term regulation of vascular tone and blood pressure. Pharmacological agents or mutations in the ␣ 2 Na ϩ pump that interfere with the action of ouabain on the pump, and reduced NCX1 expression or agents that block NCX all impede the development of salt-dependent or ouabain-induced hypertension. Conversely, nanomolar ouabain, reduced ␣ 2 Na ϩ pump expression, and smooth muscle-specific overexpression of NCX1 all induce hypertension. Furthermore, ouabain and reduced ␣ 2 Na ϩ pump expression increase myogenic tone in isolated mesenteric small arteries in vitro, thereby tying these effects directly to the elevation of blood pressure. Thus, endogenous ouabain, and vascular ␣ 2 Na ϩ pumps and NCX1, are critical links between salt and hypertension. New pharmacological agents that act on these molecular links have potential in the clinical management of hypertension.ouabain; Na ϩ pump; Na/Ca exchanger; Ca 2ϩ ; myogenic tone HYPERTENSION, DEFINED AS A diastolic blood pressure (BP) Ն 90 mmHg and/or systolic BP Ն 140 mmHg, is endemic in Westernized societies. This is a very important public health issue because hypertension is a major risk factor for premature death and disability from heart attack, heart failure, stroke, and many other afflictions (16,59). In the United States, alone, Ϸ20% of the population (i.e., Ϸ50 million individuals) are hypertensive; moreover, more than half of all individuals over the age of 60 years have hypertension. In a small fraction of cases, the hypertension is due to specific causes, such as renal vascular disease or excessive secretion of aldosterone (primary aldosteronism) or catecholamines (pheochromocytoma). The vast majority (Ϸ90%) of patients, however, have elevated BP of unknown cause; hence the terms, primary or essential hypertension. The immediate cause for the elevated BP in nearly all chronic hypertensive persons is excessive narrowing of the small (resistance) arteries. Nevertheless, a key question in any discussion of hypertension is: What specific mechanisms actually lead to the abnormal arterial constriction and elevation ...

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Section: Endogenous Ouabain and Other Endogenous Cardiotonic Steroidsmentioning

confidence: 99%

How does salt retention raise blood pressure?

Blaustein¹,

Zhang²,

Ling³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

129

121

View full text Add to dashboard Cite

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“…Evidence in human hypertension Accumulating evidence has suggested that several sodium pumpinhibitors, similar to cardiotonic steroids, are present in the human body (54). Ouabain-like factor, the most appealing candidate, has been found to increase with high sodium intake and hypervolemia, as well as essential hypertension (55).…”

Section: Ouabain-like Factormentioning

confidence: 99%

Recent Aspects in the Genetic Renal Mechanisms Involved in Hypertension.

1999

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The kidney plays an important role in the blood pressure regulation primarily by modulating tubular sodium reabsorption. Various hormones, vasoactive peptides, autacoids and transporters or channels in renal tubules are involved in this process. Genes associated with renal tubular sodium handling are possibly related to the development of hypertension. Genes of the renin-angiotensin-aldosterone system are thought to be especially important as causal genes of hypertension. Na-K-ATPase, biochemically equal to Na pump, exists on the basolateral membrane of renal epithelial cells. It plays a central role in Na reabsorption and creates a driving force for transepithelial transport. Na-K-ATPaseactivity is regulated by adducin, a membrane-bound skeletal protein, as well as by several hormones such as dopamine, endogenous ouabain-like factor or cytochrome P450 metabolites. Genes of these factors involved in Na-K-ATPaseregulation should be related to the development of hypertension. The endothelin system, atrial natriuretic peptide and nitric oxide regulate the tonus of blood vessels as well as renal sodiumexcretion. Several reports have indicated that genes of these substances are crucial in the pathogenesis of hype rtension. (Internal Medicine 38: 919-926, 1999)

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“…It has been postulated for some time that endogenous substances [sodium pump inhibitors (SPI)] are stimulated by increased Na intake and increase natriuresis by inhibiting renal tubular Na pumps to prevent renal reabsorption of filtered Na (6,18,30). However, such substances were not purified adequately in early studies, and their assays were nonspecific (17).More recently, SPI assays have improved and become more specific (3,14), and studies in various animal models and in humans have documented an increased elaboration of SPI in response to NaCl loading. This research has focused largely on two SPI: an endogenous ouabain (EO) and a bufadienoide, marinobufagenin (MBG).…”

mentioning

confidence: 99%

“…More recently, SPI assays have improved and become more specific (3,14), and studies in various animal models and in humans have documented an increased elaboration of SPI in response to NaCl loading. This research has focused largely on two SPI: an endogenous ouabain (EO) and a bufadienoide, marinobufagenin (MBG).…”

mentioning

confidence: 99%

Endogenous sodium pump inhibitors and age-associated increases in salt sensitivity of blood pressure in normotensives

Anderson¹,

Федорова²,

Morrell³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

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AY, Lakatta EG. Endogenous sodium pump inhibitors and age-associated increases in salt sensitivity of blood pressure in normotensives. Am J Physiol Regul Integr Comp Physiol 294: R1248-R1254, 2008. First published February 20, 2008 doi:10.1152/ajpregu.00782.2007.-Factors that mediate increases in salt sensitivity of blood pressure with age remain to be clarified. The present study investigated 1) the effects of high-NaCl intake on two Na pump inhibitors, endogenous ouabain (EO) and marinobufagenin (MBG), in middle-aged and older normotensive Caucasian women; and 2) whether individual differences in EO and MBG are linked to variations in sodium excretion or salt sensitivity. A change from 6 days of a lower (0.7 mmol ⅐ kg Ϫ1 ⅐ day Ϫ1 )-to 6 days of a higher (4 mmol ⅐ kg Ϫ1 ⅐ day Ϫ1 )-NaCl diet elicited a sustained increase in MBG excretion that directly correlated with an increase in the fractional Na excretion and was inversely related to age and to an age-dependent increase in salt sensitivity. In contrast, EO excretion increased only transiently in response to NaCl loading and did not vary with age or correlate with fractional Na excretion or salt sensitivity. A positive correlation of both plasma and urine levels of EO and MBG during salt loading may indicate a casual link between two Na pump inhibitors in response to NaCl loading, as observed in animal models. A linear mixed-effects model demonstrated that age, dietary NaCl, renal MBG excretion, and body mass index were each independently associated with systolic blood pressure. Thus, a sustained increase in MBG in response to acutely elevated dietary NaCl is inversely linked to salt sensitivity in normotensive middle-aged and older women, and a relative failure of MBG elaboration by these older persons may be involved in the increased salt sensitivity with advancing age. marinobufagenin; ouabain; hypertension NUMEROUS STUDIES HAVE REPORTED that the magnitude of the systolic blood pressure (SBP) response to acute changes in dietary NaCl intake, i.e., salt sensitivity of blood pressure, increases with advancing age (16,20,27,(32)(33)(34)(35). Specific determinants of the greater blood pressure response of older persons to dietary NaCl, however, remain to be identified.NaCl ingestion results in an increase in plasma volume and natriuresis. It has been postulated for some time that endogenous substances [sodium pump inhibitors (SPI)] are stimulated by increased Na intake and increase natriuresis by inhibiting renal tubular Na pumps to prevent renal reabsorption of filtered Na (6,18,30). However, such substances were not purified adequately in early studies, and their assays were nonspecific (17).More recently, SPI assays have improved and become more specific (3,14), and studies in various animal models and in humans have documented an increased elaboration of SPI in response to NaCl loading. This research has focused largely on two SPI: an endogenous ouabain (EO) and a bufadienoide, marinobufagenin (MBG). Differences in the kinetics and tissue actions of thes...

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Ouabain-like Factor Quantification in Mammalian Tissues and Plasma

Cited by 116 publications

References 30 publications

How does salt retention raise blood pressure?

How does salt retention raise blood pressure?

Recent Aspects in the Genetic Renal Mechanisms Involved in Hypertension.

Endogenous sodium pump inhibitors and age-associated increases in salt sensitivity of blood pressure in normotensives

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