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Steppan D, Zügner A, Rachel R, Kurtz A. Structural analysis suggests that renin is released by compound exocytosis. Kidney Int 2013; 83:233-41. [DOI: 10.1038/ki.2012.392] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Gonzalez-Villalobos RA, Satou R, Ohashi N, Semprun-Prieto LC, Katsurada A, Kim C, Upchurch GM, Prieto MC, Kobori H, Navar LG. Intrarenal mouse renin-angiotensin system during ANG II-induced hypertension and ACE inhibition. Am J Physiol Renal Physiol 2009; 298:F150-7. [PMID: 19846570 DOI: 10.1152/ajprenal.00477.2009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Angiotensin-converting enzyme (ACE) inhibition (ACEi) ameliorates the development of hypertension and the intrarenal ANG II augmentation in ANG II-infused mice. To determine if these effects are associated with changes in the mouse intrarenal renin-angiotensin system, the expression of angiotensinogen (AGT), renin, ACE, angiotensin type 1 receptor (AT(1)R) mRNA (by quanitative RT-PCR) and protein [by Western blot (WB) and/or immunohistochemistry (IHC)] were analyzed. C57BL/6J male mice (9-12 wk old) were distributed as controls (n = 10), ANG II infused (ANG II = 8, 400 ng x kg(-1) x min(-1) for 12 days), ACEi only (ACEi = 10, lisinopril, 100 mg/l), and ANG II infused + ACEi (ANG II + ACEi = 11). When compared with controls (1.00), AGT protein (by WB) was increased by ANG II (1.29 +/- 0.13, P < 0.05), and this was not prevented by ACEi (ACEi + ANG II, 1.31 +/- 0.14, P < 0.05). ACE protein (by WB) was increased by ANG II (1.21 +/- 0.08, P < 0.05), and it was reduced by ACEi alone (0.88 +/- 0.07, P < 0.05) or in combination with ANG II (0.80 +/- 0.07, P < 0.05). AT(1)R protein (by WB) was increased by ANG II (1.27 +/- 0.06, P < 0.05) and ACEi (1.17 +/- 0.06, P < 0.05) but not ANG II + ACEi [1.15 +/- 0.06, not significant (NS)]. Tubular renin protein (semiquantified by IHC) was increased by ANG II (1.49 +/- 0.23, P < 0.05) and ACEi (1.57 +/- 0.15, P < 0.05), but not ANG II + ACEi (1.10 +/- 0.15, NS). No significant changes were observed in AGT, ACE, or AT(1)R mRNA. In summary, reduced responses of intrarenal tubular renin, ACE, and the AT(1)R protein to the stimulatory effects of chronic ANG II infusions, in the presence of ACEi, are associated with the effects of this treatment to ameliorate augmentations in blood pressure and intrarenal ANG II content during ANG II-induced hypertension.
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Affiliation(s)
- Romer A Gonzalez-Villalobos
- Dept. of Physiology, Tulane Univ. Health Sciences Center, 1430 Tulane Ave., SL39, New Orleans, LA 70112, USA.
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Zhang Y, Wu J, Wang X, Morgan T. Effects of enalapril and sodium depletion on the renin-angiotensin system in hydronephrotic mice. Can J Physiol Pharmacol 2009; 87:515-21. [DOI: 10.1139/y09-037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of enalapril and sodium depletion on renin synthesis and secretion were studied in mice with a left hydronephrotic kidney caused by unilateral ureteral ligation (UUL). In the control animals, there was no difference in plasma renin concentration between the right and left renal veins. In mice with left ureteral ligation, the renin concentration in the vein draining the hydronephrotic kidney was similar to or lower than that in the aorta under control conditions and after either stimulation with enalapril or depletion of sodium. Enalapril and sodium restriction increased plasma renin concentration, and this increase was due to secretion from the nonhydronephrotic kidney. The renin concentration per gram of kidney tissue and the mRNA for renin per gram of kidney tissue were similar in both the control and hydronephrotic kidney, and the values rose 3–4-fold in both kidneys after enalapril or sodium depletion. Immunostaining for renin confirmed these findings and indicated that renin per glomerulus was higher in the hydronephrotic kidney. Thus, removal or reduction of angiotensin II activity or depletion of sodium stimulated synthetic activity to a similar extent in the normal and hydronephrotic kidneys; however, secretion from the kidney without a macula densa (hydronephrotic) was not increased. Thus, the signals that control synthesis and secretion are different, and for these stimuli, secretion appears to require an intact macula densa.
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Affiliation(s)
- Yanling Zhang
- Department of Physiology, Taishan Medical University, Tai’an 271000, China
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Junyan Wu
- Department of Physiology, Taishan Medical University, Tai’an 271000, China
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Xuechun Wang
- Department of Physiology, Taishan Medical University, Tai’an 271000, China
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Trefor Morgan
- Department of Physiology, Taishan Medical University, Tai’an 271000, China
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
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Hamming I, Navis G, Kocks MJA, van Goor H. ACE inhibition has adverse renal effects during dietary sodium restriction in proteinuric and healthy rats. J Pathol 2006; 209:129-39. [PMID: 16532430 DOI: 10.1002/path.1956] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Angiotensin-converting enzyme inhibitors (ACEi) provide renoprotection. A low sodium diet enhances their efficacy. However, the added effect of sodium restriction on proteinuria and blood pressure is not invariably associated with better preservation of renal morphology, suggesting that the combination of ACEi with a low sodium diet can elicit renal structural abnormalities. To test this hypothesis, the effects of ACEi in combination with a control (CS) or a low sodium (LS) diet were investigated in healthy rats and in adriamycin nephrotic rats. After 3 weeks of treatment, rats were sacrificed and kidneys examined for renal structural abnormalities. In healthy rats, ACEi reduced blood pressure: the fall in blood pressure was significantly greater in the ACEi/LS group. Renal morphology was normal in the ACEi/CS group but severe interstitial damage was found in the ACEi/LS group. This was associated with increased interstitial macrophage influx and up-regulation of osteopontin, alpha-smooth muscle actin, and collagen III expression. In addition, ACEi/LS induced an increase in the total medial area of afferent arterioles. In nephrotic rats, ACEi/LS reduced both blood pressure and proteinuria, whereas only blood pressure was reduced in the ACEi/CS group. Mild interstitial damage was present in the ACEi/CS group but, strikingly, pronounced tubulo-interstitial abnormalities occurred in the ACEi/LS group, similar to those seen in ACEi/LS healthy rats, with similar changes in afferent arteriolar walls. In conclusion, the combination of ACEi/LS elicits pronounced renal interstitial abnormalities in healthy and nephrotic rats, despite a significant reduction of proteinuria in the latter. Considering their occurrence in healthy rats, these renal adverse effects cannot be due to specific characteristics of adriamycin nephrosis. Further studies should elucidate the mechanisms underlying these observations and their impact on long-term renoprotection.
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Affiliation(s)
- I Hamming
- Department of Pathology and Laboratory Medicine, University Medical Center Groningen and University of Groningen, The Netherlands.
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Bralet J, Marie C, Gros C, Schwartz JC, Lecomte JM. Fasidotril: The First Dual Inhibitor of Neprilysin and ACE. ACTA ACUST UNITED AC 2006. [DOI: 10.1111/j.1527-3466.2000.tb00030.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
1. Increased sodium intake causes decreased formation of angiotensin (Ang) II and increased AngII causes increased Na+ retention. 2. Increased sodium intake and increased AngII causes cardiac hypertrophy, but decreased sodium intake regresses cardiac hypertrophy despite high AngII levels. Likewise, decreased Na+ and blockers of the renin-angiotensin system (RAS) in neonatal rats have similar effects on subsequent blood pressure development. 3. Cardiac hypertrophy due to renal hypertension does not regress when the RAS is blocked and rats are on a high salt intake. Likewise, sodium restriction alone does not cause regression; combination of reduced NaCl intake and RAS blockade is required. 4. High doses of perindopril and losartan in combination cause a syndrome in rats on 0.2% NaCl that leads to profound hypotension, polyuria, renal impairment and involution of the heart and death. This is reversed or prevented by a high (4%) NaCl intake, which also prevents the plasma angiotensinogen depletion that occurs with combined blockade on 0.2% NaCl intake. 5. Intake of NaCl and AngII interact at many levels. It is postulated that there is an important interaction at the cellular level that can explain the above events.
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Affiliation(s)
- T Morgan
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia.
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Griffiths CD, Morgan TO, Delbridge LM. Effects of combined administration of ACE inhibitor and angiotensin II receptor antagonist are prevented by a high NaCl intake. J Hypertens 2001; 19:2087-95. [PMID: 11677376 DOI: 10.1097/00004872-200111000-00021] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND To prevent the action of angiotensin II by blockade with either an angiotensin converting enzyme inhibitor (ACE I) or an angiotensin receptor antagonist (ARA) is difficult due to the physiological compensations. Combined therapy with both drugs may enable complete blockade, and in rats in high doses this has produced a syndrome that results in death. OBJECTIVE To determine the effect of combined blockade using losartan (10 mg/kg per day) and perindopril (6 mg/kg per day) on blood pressure, cardiac growth, renal function and behaviour, and to determine how this is influenced by different salt intakes in normotensive Sprague Dawley rats. METHODS Rats were fed an 0.2 or 4% NaCl diet and received the above drugs intraperitoneally. Blood pressure was measured by telemetry. Cardiac weight was measured after 10 days of therapy. Renal function was assessed by plasma creatinine and electrolytes, plasma renin and angiotensinogen concentrations were measured. RESULTS On 0.2% NaCl intake, combined blockade lowered blood pressure progressively; at day 7, rats on 0.2% NaCl developed a syndrome of listlessness and failure to eat which led to loss of weight and death. Cardiac size was dramatically reduced. Plasma creatinine was elevated to 50% above normal. There was a polyuria. The syndrome was reversed by adding NaCl to the drinking water or prevented in rats on a 4% NaCl intake. In rats on 0.2% NaCl plasma renin rose dramatically with medication and angiotensinogen became depleted. Haematocrit in all groups of rats did not differ. CONCLUSION Combined blockade of the renin-angiotensin system can cause death in rats on a reduced NaCl intake. This was prevented by a high salt intake. The syndrome may result from depletion of angiotensinogen and the failure to synthesize sufficient angiotensin II that may be critical for normal cardiac growth and function and critical for survival.
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Affiliation(s)
- C D Griffiths
- Department of Physiology, University of Melbourne, Victoria, Australia
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Golin R, Pieruzzi F, Munforti C, Busca G, Di Blasio A, Zanchetti A. Role of the renal nerves in the control of renin synthesis during different sodium intakes in the rat. J Hypertens 2001; 19:1271-7. [PMID: 11446717 DOI: 10.1097/00004872-200107000-00012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the role of the renal nerves in the regulation of renin synthesis in normotensive rats at different sodium balance. METHODS Forty-eight male Sprague-Dawley rats were divided in six experimental groups, combining three diets at different NaCl content (normal 0.4%, low 0.04% or high 4.0%), and the surgical, bilateral renal denervation or the sham procedure. After 7 days of dietary treatment, all rats were sacrificed and plasma renin activity (PRA) was measured. Renin messenger RNA (mRNA) levels in the renal cortex were determined by semiquantitative polymerase chain reaction. RESULTS PRA was higher in animals fed the low sodium diet compared with those at standard diet, while it was lower in animals fed the high sodium diet. Renal denervation decreased PRA in normal and low sodium groups, while it did not alter the PRA values in the high sodium group. Renin gene expression significantly increased in rats fed with the low sodium diet compared with the standard diet group, and significantly decreased in rats fed the high sodium diet Renal denervation significantly reduced renin mRNA levels in rats receiving the low sodium diet, but did not produce any significant change in normal or high-sodium groups. CONCLUSION The activation of renin gene expression during sodium depletion in rats is dependent on the presence of the renal nerves, while the suppression of renin gene expression during a sodium load seems to be due to the macula densa mechanism alone.
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Affiliation(s)
- R Golin
- Centro di Fisiologia Clinica e Ipertensione, University of Milan, Ospedale Maggiore--IRCCS, Italy.
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Abro E, Griffiths CD, Morgan TO, Delbridge LMD. Regression of cardiac hypertrophy in the SHR by combined renin-angiotensin system blockade and dietary sodium restriction. J Renin Angiotensin Aldosterone Syst 2001; 2:S148-S153. [DOI: 10.1177/14703203010020012601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Altered operation of the renin-angiotensin-aldosterone system (RAAS) and dietary sodium intake have been identified as independent risk factors for cardiac hypertrophy. The way in which sodium intake and the operation of the renin-angiotensin-aldosterone system interact in the pathogenesis of cardiac hypertrophy is poorly understood. The aims of this study were to investigate the cardiac effects of the renin-angiotensin system (RAS) blockade in the spontaneously hypertensive rat (SHR), using co-treatment with an angiotensin II receptor blocker (ARB) and an angiotensin-converting enzyme (ACE) inhibitor with different sodium intakes. Our experiments with SHR show that, at high levels of sodium intake (4.0%), aggressive RAS blockade treatment with candesartan (3 mg/kg) and perindopril (6 mg/kg) does not result in regression of cardiac hypertrophy. In contrast, RAS blockade coupled with reduced sodium diet (0.2%) significantly regresses cardiac hypertrophy, impairs animal growth and is associated with elevated plasma renin and dramatically suppressed plasma angiotensinogen levels. Histological analyses indicate that the differential effect of reduced sodium on heart growth during RAS blockade is not associated with any change in myocardial interstitial collagen, but reflects modification of cellular geometry. Dimensional measurements of enzymatically-isolated ventricular myocytes show that, in the RAS blocked, reduced sodium group, myocyte length and width were decreased by about 16—19% compared with myocytes from the high sodium treatment group. Our findings highlight the importance of `titrating' sodium intake with combined RAS blockade in the clinical setting to optimise therapeutic benefit.
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Affiliation(s)
- Emad Abro
- Department of Physiology, University of Melbourne, Parkville,
Victoria, 3010, Australia
| | - Cory D Griffiths
- Department of Physiology, University of Melbourne, Parkville,
Victoria, 3010, Australia
| | - Trefor O Morgan
- Department of Physiology, University of Melbourne, Parkville,
Victoria, 3010, Australia
| | - Lea MD Delbridge
- Department of Physiology, University of Melbourne, Parkville,
Victoria, 3010, Australia,
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Extended angiotensin converting enzyme inhibition changes the innervation of renal glomerular afferent arterioles. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0165-1838(99)00047-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yan Y, Hu L, Chen R, Sealey JE, Laragh JH, Catanzaro DF. Appropriate regulation of human renin gene expression and secretion in 45-kb human renin transgenic mice. Hypertension 1998; 32:205-14. [PMID: 9719044 DOI: 10.1161/01.hyp.32.2.205] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To create physiological models of the human renin-angiotensin system in transgenic animals, the component genes should be expressed in the correct tissues and cells and respond appropriately to physiological stimuli. We recently showed that mice carrying a 45-kb human renin genomic fragment, containing approximately 25 kb 5'-flanking DNA and 6 kb 3'-flanking DNA, express the transgene in a highly cell- and tissue-specific pattern. More importantly, in contrast to previous models, human renin in the circulating plasma of these mice is derived exclusively from the kidneys. In the present study, we tested the responses of both human and mouse renal renin expression and secretion of the 45-kb hREN transgenic mice to a variety of physiological and pharmacological stimuli. A sodium-deficient diet, angiotensin-converting enzyme inhibition, and beta1-adrenergic stimulation each increased both human and mouse plasma renin concentration significantly, whereas elevated blood pressure and/or increased plasma angiotensin II levels suppressed them. Human and mouse renal renin mRNA levels changed similarly but to a lesser degree. These studies demonstrate that human renin synthesis and secretion respond appropriately in 45-kb hREN mice to physiological stimuli. This most likely results from appropriate cell-specific expression of the transgene conferred by the extended transgene flanking sequences.
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Affiliation(s)
- Y Yan
- Cardiovascular Center, Cornell University Medical College, New York, NY 10021, USA
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Danser AH, Derkx FH, Schalekamp MA, Hense HW, Riegger GA, Schunkert H. Determinants of interindividual variation of renin and prorenin concentrations: evidence for a sexual dimorphism of (pro)renin levels in humans. J Hypertens 1998; 16:853-62. [PMID: 9663926 DOI: 10.1097/00004872-199816060-00017] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Plasma renin concentrations are an important factor in cardiovascular risk profiling. OBJECTIVE To investigate the effects of sex, medication, and anthropometric factors that may contribute to the interindividual variation in the plasma concentrations of renin and its precursor prorenin. DESIGN AND METHODS Prorenin and renin levels in 327 men and 383 women, aged 52-69 years, who participated in a 1994 reexamination of a previous population survey in Bavaria, were measured by immunoradiometric assay. RESULTS Prorenin and renin levels in men were significantly higher than those in women, those in women without estrogen replacement therapy were significantly higher than those in women with estrogen replacement therapy, and those in diabetics were significantly higher than those in nondiabetics. Prorenin level was correlated negatively to blood pressure and positively to age and the use of diuretics; it was normal in subjects using angiotensin converting enzyme inhibitors and beta-adrenergic antagonists (beta-blockers). Renin level was correlated negatively to atrial natriuretic peptide level and the use of beta-blockers, and it was elevated above normal levels in subjects using angiotensin converting enzyme inhibitors and diuretics as well as in subjects who had previously suffered myocardial infarction. After exclusion of data for women being administered estrogen replacement therapy, multivariate analysis revealed that sex (P<0.001), age (P<0.02), blood pressure (P<0.002), diabetes (P<0.05), and the use of angiotensin converting enzyme inhibitors (P<0.002), beta-blockers (P<0.001), and diuretics (P<0.05) were independent determinants of plasma prorenin. Plasma renin was independently related to atrial natriuretic peptide level (P<0.01) and the use of angiotensin converting enzyme inhibitors (P<0.001), beta-blockers (P<0.001), and diuretics (P<0.05). CONCLUSIONS These data demonstrate that there is a sexual dimorphism of prorenin levels in humans, suggesting that sex hormones affect the regulation of the renin gene. Data confirm previous reports of elevated prorenin levels in diabetics and older subjects, as well as of lower than normal prorenin levels in subjects with hypertension in smaller populations. Our findings may help to clarify the potential (patho)physiologic functions of prorenin and to identify the factors that influence the constitutive secretion and intracellular processing of this prohormone.
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Affiliation(s)
- A H Danser
- Department of Pharmacology, Cardiovasculaire Onderzoeksinstituut Erasmus Universiteit Rotterdam, The Netherlands.
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Ibarra-Rubio ME, Ramos M, Correa-Rotter R, Pedraza-Chaverrí J. Renin, prorenin, and renin gene expression in rats with acute nephrotic syndrome. Clin Exp Pharmacol Physiol 1997; 24:408-14. [PMID: 9171944 DOI: 10.1111/j.1440-1681.1997.tb01210.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1. The concentration of total, active and inactive renin was analysed in plasma, urine and kidney from control (C), pair-fed (PF) and nephrotic (NS) rats, as well as renin mRNA levels in kidney, liver and brain. 2. Nephrotic syndrome were induced by a single subcutaneous injection of puromycin aminonucleoside (PAN) and determinations were made 6 days after PAN injection. 3. Plasma total renin did not change, active renin increased in NS rats with respect to PF and C groups and in PF rats with respect to C. In contrast, the inactive renin percentage decreased in NS rats with respect to PF and C groups and in PF animals with respect to C. Total, active and inactive renal renin content did not change and active and inactive renin were significantly excreted by urine with no changes in the prorenin percentage with respect to C and PF groups. 4. In both NS and PF groups, renin mRNA levels did not change in any of the tissues studied. In another group of rats, kidney renin mRNA levels were measured on days 1, 3, 5 and 7 after PAN injection and no time-course changes in its expression were found. 5. These results suggest that renin gene expression is not altered in acute nephrotic syndrome and that plasma renin concentration is regulated at the translational or post-translational level in this experimental model.
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Affiliation(s)
- M E Ibarra-Rubio
- Departamento de Nefrología y Metabolismo Mineral, Instituto Nacional de la Nutrición Salvador Zubirán, México DF.
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Neri Serneri GG, Boddi M, Coppo M, Chechi T, Zarone N, Moira M, Poggesi L, Margheri M, Simonetti I. Evidence for the existence of a functional cardiac renin-angiotensin system in humans. Circulation 1996; 94:1886-93. [PMID: 8873664 DOI: 10.1161/01.cir.94.8.1886] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The presence of mRNA for the essential components of the renin-angiotensin system (RAS) has been found in animal and human hearts. The present study was designed to provide evidence for the existence of a (functional) cardiac RAS. METHODS AND RESULTS Twenty-four patients with atypical chest pain undergoing coronary angiography for diagnostic purposes were investigated. The cardiac production rate of angiotensins was estimated by measurement of the cardiac extraction of 125I-angiotensin I and 125I-angiotensin II associated with the determination of endogenous angiotensins in aortic and coronary sinus blood in normal, low, or high sodium diets. In a normal sodium diet, angiotensin I and II aorta-coronary sinus gradients were tendentially negative (-1.8 +/- 2.5 and -0.9 +/- 1.7 pg/mL, respectively), and the amounts of angiotensin I and II added by cardiac tissues were 6.5 +/- 3.1 and 2.7 +/- 1.3 pg/mL, respectively. The low sodium diet caused a significant increase in both plasma renin activity (PRA) and angiotensin I concentration in aortic but not in coronary sinus blood, resulting in a more negative aorta-coronary sinus gradient (-9.7 +/- 3.1 pg/mL, P < .01). Angiotensin formation by PRA in blood during transcardiac passage increased (P < .001), whereas angiotensin I formed by cardiac tissues decreased dramatically. Accordingly, in the low sodium diet, 125I-angiotensin II extraction did not change, the cardiac fractional conversion rate of 125I-angiotensin I to 125I-angiotensin II notably decreased (P < .01), and angiotensin II formation by cardiac tissues was undetectable. The high sodium diet caused a decrease in PRA and no changes in cardiac extraction of radiolabeled angiotensins; conversely, angiotensin I formed by cardiac tissues, cardiac Ang I fractional conversion rate, and angiotensin II formed during transcardiac passage significantly (P < .01 for all) increased. CONCLUSIONS These results provide evidence for the existence of a functional cardiac RAS independent of but related to the circulating RAS.
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Affiliation(s)
- G G Neri Serneri
- Istituto di Clinica Medica Generale e Cardiologia, University of Florence, Italy
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15
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Zhang Y, Morgan TO. Sodium depletion, renal denervation, beta adrenergic blockage and renin secretion and synthesis. Blood Press 1994; 3:67-71. [PMID: 7911056 DOI: 10.3109/08037059409101523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The role of the macula densa in the control of renin synthesis during sodium depletion was studied in Balb/c mice which had their left kidney made hydronephrotic 6 weeks earlier. The role of the nervous system was studied by giving the mice propranolol or by denervation of the left kidney. There was no net secretion of renin from the left hydronephrotic kidney on control or low sodium diet. All plasma renin came from the right kidney. Sodium depletion caused similar rises in renin content of the normal and hydronephrotic kidney. These rises were accompanied by increases in mRNA for renin in both kidneys. Denervation of the left hydronephrotic kidney caused a fall in renal renin content. However, sodium depletion caused a significant rise in both renin mRNA and renal renin in the control and denervated hydronephrotic kidney. Propranolol decreased the renin content of normal and hydronephrotic kidneys. Sodium depletion caused a rise in mRNA and renal renin in both kidneys although the absolute final amount was less than in the control animals. Sodium depletion stimulates renin synthesis in a normal kidney and a kidney without a macula densa. This response is not affected by the nervous supply to the kidney. In the hydronephrotic mouse subjected to sodium depletion the synthesis and secretion of renin appear to be disassociated.
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Affiliation(s)
- Y Zhang
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
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16
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Zhang Y, Morgan T. Effects of enalapril and Dup753 on renin synthesis in mice with one hydronephrotic kidney. Clin Exp Pharmacol Physiol 1994; 21:133-5. [PMID: 8039266 DOI: 10.1111/j.1440-1681.1994.tb02481.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1. Renin synthesis and secretion were investigated in mice with one hydronephrotic kidney. 2. Enalapril and Dup753 stimulated renin synthesis to a similar extent in the hydronephrotic and normal kidney. 3. Hydronephrosis did not prevent an increase in renin mRNA caused by enalapril and Dup753. 4. The results therefore indicate that the macula densa does not appear to be crucial for renin synthesis in the kidney under the inhibition of angiotensin II. 5. Thus angiotensin II plays an important role controlling renin gene expression in both the normal and hydronephrotic kidneys.
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Affiliation(s)
- Y Zhang
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
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Schunkert H, Ingelfinger JR, Hirsch AT, Pinto Y, Remme WJ, Jacob H, Dzau VJ. Feedback regulation of angiotensin converting enzyme activity and mRNA levels by angiotensin II. Circ Res 1993; 72:312-8. [PMID: 8380358 DOI: 10.1161/01.res.72.2.312] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Although renin and angiotensinogen are known to be subject to feedback regulation, the effects of angiotensin II (Ang II) on the regulation of angiotensin converting enzyme (ACE) gene expression and enzymatic activity have not yet been studied. Therefore, the effects of exogenous Ang II infusion and ACE inhibition on ACE mRNA expression were examined. Ang II was infused intravenously in male Sprague-Dawley rats for 3 days at 100 (low dose), 300 (medium dose), or 1,000 (high dose) ng/kg per minute (n = 8 for each group). Compared with control (vehicle infusion, n = 8), Ang II infusion increased plasma Ang II concentration (62, 101, 126 [p < 0.05], and 187 [p < 0.05] fmol/ml) and mean arterial blood pressure (106, 119 [p < 0.05], 134 [p < 0.05], and 125 mm Hg for control, low, medium, and high doses, respectively). Ang II infusion decreased ACE mRNA levels in the lung (57%, 52%, and 51%; p < 0.05 for each) and testis (49%, 63%, and 53% of control for low, medium, and high doses, respectively; p < 0.05 for each), two major sites of ACE synthesis. There was, albeit less pronounced, a parallel decrease in pulmonary ACE activity (4.38, 3.92, 3.07 [p < 0.05], and 3.48 [p < 0.05] nM/mg per minute for control, medium, and high doses, respectively). In contrast, serum (54, 50, 48, and 38 [p < 0.05] nM/ml per minute) and testicular (2.63, 2.08 [p < 0.05], 2.24, and 2.18 nM/mg per minute for control, low, medium, and high doses, respectively) ACE activities displayed only minimal change in animals infused with Ang II.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H Schunkert
- Falk Cardiovascular Research Center, Stanford, Calif
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18
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Chen M, Schnermann J, Malvin RL, Killen PD, Briggs JP. Time course of stimulation of renal renin messenger RNA by furosemide. Hypertension 1993; 21:36-41. [PMID: 8418022 DOI: 10.1161/01.hyp.21.1.36] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Renin secretion responds rapidly to a variety of stimuli; however, reported changes in renal renin messenger RNA (mRNA) levels in vivo have been observed only after prolonged stimulation. Studies were designed to test whether rapid changes in renin mRNA levels can be produced in vivo. In the first series, Sprague-Dawley rats received furosemide (10 mg/kg) intraperitoneally and a low sodium diet (0.05% sodium); renin secretion was significantly stimulated at 8 or 16 hours after treatment, but renin mRNA levels did not change. In a second series, rats were pretreated with deoxycorticosterone acetate (200 mg/kg) and saline drinking water for 3 days and then killed 0, 2, 4, 8, or 48 hours after furosemide administration. The renin mRNA level was unchanged at 2 hours but was stimulated twofold at 4 and 8 hours and threefold at 48 hours. In additional animals, the response of renin mRNA 4 hours after furosemide was found not to be potentiated by the converting enzyme inhibitor quinapril (5 mg/kg). The results demonstrate that with acute stimulation, renin mRNA levels lag 2-4 hours behind the change in plasma renin levels.
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Affiliation(s)
- M Chen
- Department of Physiology, University of Michigan, Ann Arbor 48109-0676
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19
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Morishita R, Higaki J, Nagano M, Nakamura F, Tomita N, Zhao Y, Mikami H, Miyazaki M, Ogihara T. Discrepancy between renin mRNA and plasma renin level in angiotensin-converting enzyme inhibitor-treated rats. Clin Exp Pharmacol Physiol 1993; 20:15-20. [PMID: 8381736 DOI: 10.1111/j.1440-1681.1993.tb01497.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
1. To investigate the role of transcriptional and post-transcriptional factors in increasing renin synthesis secondary to angiotensin-converting enzyme (ACE) inhibitors, we studied the changes in levels of renal renin mRNA, plasma renin and other hormonal factors. 2. Spontaneously hypertensive rats were orally administered 10 mg/kg spirapril or vehicle daily for 3, 14 or 28 days. 3. Plasma renin activity in the spirapril-treated group was significantly elevated compared with that in the vehicle group at any time (P < 0.01). However, there was no significant change in plasma angiotensin II concentration between the two groups. The ratio of renal renin mRNA to beta-actin mRNA in the spirapril-treated group was higher than that in the control group (P < 0.01). 4. At 28 days, plasma renin activity in the spirapril-treated group was significantly elevated compared with that at 14 days (P < 0.05). However, there was no change in renin mRNA between 14 and 28 days after ACE inhibitor administration. 5. Plasma ACE activity in the treatment group was less than that in the control group at any time (P < 0.01). 6. Our study demonstrated a non-proportional change in plasma renin and renal renin mRNA levels. It is suggested that the main determinant of the rate of renin synthesis after administration of an ACE inhibitor may be post-transcriptional factors, and that unknown mechanisms may be involved in the increase in plasma renin level after long-term administration of ACE inhibitor in addition to the short feedback mechanism brought about by the decrease in angiotensin II.
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Affiliation(s)
- R Morishita
- Department of Geriatric Medicine, Osaka University Medical School, Japan
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20
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Schunkert H, Ingelfinger JR, Jacob H, Jackson B, Bouyounes B, Dzau VJ. Reciprocal feedback regulation of kidney angiotensinogen and renin mRNA expressions by angiotensin II. THE AMERICAN JOURNAL OF PHYSIOLOGY 1992; 263:E863-9. [PMID: 1443118 DOI: 10.1152/ajpendo.1992.263.5.e863] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present study asks whether angiotensin II (ANG II), a potent inhibitor of renal renin synthesis and release, regulates renal angiotensinogen synthesis. ANG II (or vehicle) was intravenously infused into male Sprague-Dawley rats for 3 days (vehicle or 100, 300, and 1,000 ng.kg-1 x min-1, n = 8/group), significantly increasing mean plasma ANG II concentrations and raising mean arterial blood pressure (MAP). ANG II dose dependently suppressed plasma renin concentration, kidney renin concentration, and renal renin mRNA levels. In contrast, ANG II infusion increased renal angiotensinogen mRNA levels stepwise to 122, 136 (P < 0.05), and 150% (P < 0.05) of control and also increased both liver mRNA levels (P < 0.05) and plasma angiotensinogen concentration (P < 0.05). Three days of angiotensin-converting enzyme inhibition (10 mg.kg-1 x day-1 quinapril in drinking water, n = 8) significantly decreased MAP (P < 0.05) and increased both mean plasma renin concentration (P < 0.05) and renal renin mRNA levels (P < 0.005). Plasma ANG II concentration tended to decrease (not significant), and neither renal nor hepatic angiotensinogen mRNA levels displayed significant difference. However, when data from ANG II-infused and quinapril-treated rats were analyzed together, correlation between plasma ANG II concentrations and renal angiotensinogen mRNA levels was highly significant (P < 0.005, r = 0.585). Thus plasma ANG II upregulates renal angiotensinogen gene expression and downregulates renal renin gene expression, a reciprocal feedback regulation that may have important physiological consequences.
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Affiliation(s)
- H Schunkert
- Cardiovascular Research Center, Stanford University School of Medicine, California 94305-5246
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21
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Berka JL, Alcorn D, Ryan GB, Skinner SL. Renin processing studied by immunogold localization of prorenin and renin in granular juxtaglomerular cells in mice treated with enalapril. Cell Tissue Res 1992; 268:141-8. [PMID: 1499047 DOI: 10.1007/bf00338063] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Immunogold techniques were used to investigate renin processing within granular juxtaglomerular cells following short-term (6 h and 1 day) and long-term (4 weeks) enalapril treatment in female BALB/c mice. In control animals, renin protein labelling was localized to all types of granules (proto-, polymorphous, intermediate and mature) and to transport vesicles, whilst prorenin labelling was found in all these sites except mature granules, confirming that active renin is localized to mature granules only. Following short-term enalapril treatment, the exocytosis of renin protein from mature granules was increased. Long-term enalapril treatment resulted in increased numbers of transport vesicles and all types of granules, consistent with increased synthesis and storage of renin. More large intermediate granules contained discrete regions labelled for prorenin. Renin protein was exocytosed from individual and multiple granules, whilst prorenin was exocytosed from proto- and intermediate granules. It is concluded that under normal conditions prorenin is secreted constitutively by bulk flow from transport vesicles. On the other hand, active renin is secreted regulatively from mature granules. In conditions of intense stimulation (angiotensin-converting enzyme inhibition treatment), increased synthesis of prorenin leads to enhanced secretion of prorenin by both constitutive and regulative pathways. Under these conditions, the conversion of prorenin to active renin is increased, with increased secretion of active renin occurring in a regulative manner. Furthermore, the localization of prorenin to one discrete region of large intermediate granules leads us to conclude, that cleavage of the prosegment of renin occurs with the transition of intermediate to mature granules.
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Affiliation(s)
- J L Berka
- Department of Anatomy, University of Melbourne, Parkville, Victoria, Australia
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22
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Barrett G, Horiuchi M, Paul M, Pratt RE, Nakamura N, Dzau VJ. Identification of a negative regulatory element involved in tissue-specific expression of mouse renin genes. Proc Natl Acad Sci U S A 1992; 89:885-9. [PMID: 1736303 PMCID: PMC48349 DOI: 10.1073/pnas.89.3.885] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The 5' flanking region of the mouse renin genes (Ren-1d and Ren-2d) contains two motifs that are homologous to known negative regulatory elements (NREs). Ren-2d has a 150-base-pair (bp) insertion 5' to the upstream putative NRE (NRE-1), which is lacking in Ren-1d. We tested the functionality of these sequences by using site-directed mutagenesis to delete individually each putative NRE from Ren-1d and to delete the 150-bp insertion from Ren-2d. We examined the effect of these mutations on the expression of the reporter gene chloramphenicol acetyltransferase, which was expressed from a truncated thymidine kinase promoter fused to the renin regulatory region. This plasmid was transfected into human choriocarcinoma JEG-3 cells. Only the upstream NRE (positions -619 to -597) was found to be functional in Ren-1d. The deletion of a 150-bp insertion from Ren-2d resulted in the suppression of chloramphenicol acetyltransferase activity to the level of Ren-1d expression. These data suggest that the upstream NRE that is functional in Ren-1d, but not in Ren-2d, may be partly responsible for differential expression of the renin genes in various tissues. The molecular mechanism of the NRE was examined by studying its interaction with nuclear proteins in submandibular gland and JEG-3 cells by gel-mobility-shift assays. Specific nuclear protein binding was observed only to the upstream NRE and the molecular mass of this protein was approximately 72 kDa as determined by Southwestern blot analysis. Thus our results suggest that both Ren-1d and Ren-2d conserve a cis-acting NRE in the 5' flanking region. In Ren-1d, this NRE could bind a specific nuclear protein resulting in the inhibition of Ren-1d expression in these tissues. On the other hand, the NRE in Ren-2d is nonfunctional due to interference by an adjacent 150-bp insertion.
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Affiliation(s)
- G Barrett
- Division of Cardiovascular Medicine, Falk Cardiovascular Research Center, Stanford University School of Medicine, CA 94305
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Abstract
1. The role of the macula densa in renin synthesis was studied using mice with one hydronephrotic kidney. 2. Renin synthesis was assessed by measurement of renal renin, renal mRNA for renin and plasma renin. 3. Sodium depletion stimulated mRNA and renal renin to a similar extent in the hydronephrotic and contralateral kidney. 4. Enalapril stimulated mRNA concentration in both kidneys but renal renin did not rise in the hydronephrotic kidney. 5. Propranolol did not alter the response to sodium depletion in either kidney. 6. The macula densa is not crucial for the stimulation of renin synthesis following sodium depletion. However, it may regulate renin production after mRNA synthesis, possibly by controlling the conversion of prorenin to renin.
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Affiliation(s)
- T Morgan
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
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Baxter JD, Duncan K, Chu W, James MN, Russell RB, Haidar MA, DeNoto FM, Hsueh W, Reudelhuber TL. Molecular biology of human renin and its gene. RECENT PROGRESS IN HORMONE RESEARCH 1991; 47:211-57; discussion 257-8. [PMID: 1745821 DOI: 10.1016/b978-0-12-571147-0.50011-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This article describes investigations of several aspects of the molecular biology of the human renin gene and the three-dimensional structure of renin and its precursor, prorenin. Because of the importance of the RAS in hypertension, heart failure, renal failure, and possibly other disorders such as atherosclerosis, it is critical to understand the detailed control of this system. This control involves regulation at the transcriptional level, folding of prorenin, sorting of prorenin to a regulated pathway where it is proteolytically cleaved to renin and released in response to secretogogues, constitutive release of uncleaved prorenin, and nonproteolytic activation of prorenin. Currently there is great interest not only in the control of renin in the kidney, the sole source of circulating renin, but also at extrarenal sites where RAS activity may regulate cardiovascular functions. The renin gene was found to be expressed significantly in the renal juxtaglomerular cells and several other cell types. Most tissue culture cells did not express the gene; exceptions were cultured SK-LMS-1 cells and cAMP-stimulated human lung fibroblasts. Cultured human uterine-placental cells expressed the human renin gene at levels higher than in other cell types assessed. Renin mRNA had the same start site in the placental cells as the kidney and was regulated by calcium ionophores and cAMP. Thus, these cells provide primary nontransformed human cells to study the homologous human promoter. Transfected renin promoters showed cell type-specific expression and cAMP responsiveness in these cells in constructs containing as few as 102 bp of 5'-flanking DNA. DNA upstream from this appears to contain an inhibitory element(s) that may have some tissue specificity in its distribution. The cAMP response is not due to cAMP induction of a transcription factor that secondarily affects the renin promoter. A novel element may be involved, since the promoter does not contain a CRE element that mediates many cAMP responses, and the cells do not appear to respond to another known cAMP-responsive transcription factor, AP-2. Studies with transfected vectors expressing a mutant cAMP-responsive protein kinase A regulatory subunit suggest that cAMP is not responsible for basal renin promoter activity in the placental cells. By contrast, cAMP induces in essence gene activation in WI26VA4 transformed human lung fibroblasts in which renin mRNA levels increase by up to 150-fold in response to forskolin. Thus, cAMP may activate renin gene expression under certain circumstances and tissue-specific renin gene expression may be directed by more than one mechanism.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J D Baxter
- Metabolic Research Unit, University of California, San Francisco
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