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Puschett JB, Agunanne E, Uddin MN. Marinobufagenin, resibufogenin and preeclampsia. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1246-53. [PMID: 20167272 DOI: 10.1016/j.bbadis.2010.02.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 01/15/2010] [Accepted: 02/06/2010] [Indexed: 11/18/2022]
Abstract
The bufodienolides are cardiac glycosides which have the ability to inhibit the enzyme, Na(+)/K(+) ATPase (sodium potassium adenosine triphosphatase). They are cardiac inotropes, cause vasoconstriction (and, potentially, hypertension) and are natriuretic. Evidence has accrued over time which supports the view that they are mechanistically involved in volume expansion-mediated hypertension. In this communication, the authors summarize data which support the view that the bufodienolides and, in particular, marinobufagenin (MBG) are involved in the pathogenesis of preeclampsia. In a rat model of the syndrome, MBG causes hypertension, proteinuria, intrauterine growth restriction and increased weight gain. All of these phenotypic characteristics are prevented by an antagonist to MBG, resibufogenin (RBG). The "preeclamptic" animals also develop a vascular leak syndrome, resulting in hemoconcentration. Abnormalities in the MAPK (mitogen-activated protein kinase) system play a role in the mechanism by which MBG produces the abnormalities in the pregnant rat. Studies to discover the relevance of these findings to human preeclampsia are currently underway in several laboratories and clinics.
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Affiliation(s)
- J B Puschett
- Department of Medicine, Texas A&M Health Science Center, Temple, TX 76508, USA.
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2
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Abstract
Extracellular fluid volume is determined by sodium and its accompanying anions. There are control mechanisms which regulate sodium balance in the body. These include high and low pressure baroreceptors, intrarenal baroreceptors, renal autoregulation, tubuloglomerular feedback, aldosterone, and numerous other physical and hormonal factors. Sodium transport by the nephron involves active and passive processes which occur in several different nephron segments. Mechanisms of cotransport, Na(+)-H+ exchange, antiporters and ion-specific channels are all utilized by the nephron to maintain sodium balance. These regulatory factors and transport mechanisms for sodium in the kidney will he discussed in detail.
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Affiliation(s)
- S Venkatesh
- Division of Renal Diseases and Hypertension, University of Colorado Health Sciences Center, Denver, USA
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Pitts TO, McGowan JA, Chen TC, Silverman M, Rose ME, Puschett JB. Inhibitory effects of volume expansion performed in vivo on transport in the isolated rabbit proximal tubule perfused in vitro. J Clin Invest 1988; 81:997-1003. [PMID: 3350975 PMCID: PMC329623 DOI: 10.1172/jci113454] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
To examine the renal tubular sites and mechanisms involved in the effects of hypooncotic volume expansion (VE) on renal electrolyte excretion, we performed clearance and isolated tubular perfusion studies using intact and thyroparathyroidectomized (TPTX) rabbits. We also examined the effect of VE on luminal brush border transport. In the microperfusion studies, proximal convoluted (PCT) and straight (PST) tubules were taken from rabbits without prior VE or after 30 min of 6% (body wt) VE. Acute VE increased the percentage excretion of Na, Ca, and P in TPTX animals and the percentage and absolute excretions of these ions in intact rabbits. In PST from VE animals, fluid flux (Jv) was depressed compared with Jv in PST from nonVE rabbits: Jv = 0.18 +/- 0.03, (VE) vs. 0.31 +/- 0.03 nl/mm.min, (nonVE) P less than 0.02. Phosphate transport (Jp) in the PST from VE animals was also depressed: JP = 1.58 +/- 0.10 (VE) vs. 2.62 +/- 0.47 pmol/mm.min, (nonVE) P less than 0.05. Similar results were obtained with TPTX animals. In the PCT from VE animals, Jv was decreased (0.49 +/- 0.10 (VE) vs. 0.97 +/- 0.14 nl/mm.min, (nonVE) P less than 0.02), but JP was not affected significantly. Transport inhibition was stable over approximately 90 min of perfusion. In the brush border vesicle studies, sodium-dependent phosphate transport was inhibited compared with that in control animals, at the 9-, 30-, and 60-s time points. These findings indicate that the inhibition of renal ionic transport by VE occurs in both PCT and PST and is, in part, the result of a direct effect of VE on tubular transport mechanisms.
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Affiliation(s)
- T O Pitts
- Department of Medicine, Presbyterian-University, Pittsburgh, Pennsylvania
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Abstract
The incidence of congestive heart failure (CHF) in the elderly increases with age as 80% of patients hospitalised with CHF are older than 60 years of age. In this age group CHF may result from several factors such as coronary artery disease, hypertension, valvular disease or intrinsic myocardiopathies. Important alterations of renal physiology have been observed in this condition: decreases in renal plasma flow and glomerular filtration rate, and increases in renal venous pressure. Natriuretic hormone inhibition occurs and renin-angiotensin-aldosterone system activation and antidiuretic hormone secretion increase, resulting in positive water and sodium balances that contribute to the manifestations of congestive heart failure. The treatment of CHF in the elderly is similar to that in younger patients; the difference in management is determined by the severity of the disease and the side effects of the drugs used. Diuretics increase water and sodium elimination by the kidney and increase the systolic volume of the left ventricle, probably by the reduction of preload and afterload. Diuretic therapy must be pursued carefully in patients receiving digitalis, especially in those elderly individuals who may be on restricted diets: the most common adverse effects of diuretics in this age group are hypovolaemia, hyponatraemia, hypokalaemia and hypomagnesaemia.
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Edwards BR, Walker LA. Bibliography. Ann N Y Acad Sci 1982; 394:780-802. [PMID: 6758660 DOI: 10.1111/j.1749-6632.1982.tb37499.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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6
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Kosuba RB, Ivanov YI. Effect of aldosterone, vasopressin, and sodium-excreting factor on absorption in the rat jejunum. Bull Exp Biol Med 1977. [DOI: 10.1007/bf00798890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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Chanard J, Drüeke T, Pujade-Lauraine E, Lacour B, Funck-Brentano JL. Effects of saline loading on jejunal absorption of calcium, sodium, and water, and on parathyroid hormone secretion in the rat. Pflugers Arch 1976; 367:169-75. [PMID: 1034912 DOI: 10.1007/bf00585154] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
To investigate whether intestinal calcium absorption parallels that of sodium following extra-cellular fluid volume expansion, the effects of saline loading on intestinal transport of calcium, sodium and water were studied in rats by perfusing jejunal loops in situ. After calcium-free saline infusion net calcium absorption was reversed similar to that of sodium and water and net secretion occurred. Concurrently, blood-to-lumen (b-l) calcium flux, measured using 45Ca, increased significantly (P less than 0.001). Following expansion with calcium-containing Ringer a similar reversal of net calcium, sodium and water flux was also observed. Again the b-l calicum flux increased but to a significantly lesser extent (P less than 0.05). Plasma ionized calcium remained unchanged after calcium-rich Ringer loading, but decreased significantly (P less than 0.001) when calcium was omitted from the solution. Plasma immunoreactive parathyroid hormone unchanged after expansion with the calcium containing solution but increased following calcum-free infusion. It is concluded that after extracellular fluid volume expansion: 1. net jejunal calcium absorption is decreased; 2. the decrease parallels that of sodium and water; 3. b-l calcium transport is enhanced to a greater degree of calcium-free Rnger infusion than by a calcium-rich solution. This difference could be the result of increased parathyroid hormone secretion.
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Aperia A, Broberger O, Herin P. Changes in renal hemodynamics and sodium excretion during saline infusion in lambs. ACTA PHYSIOLOGICA SCANDINAVICA 1975; 94:442-50. [PMID: 1180085 DOI: 10.1111/j.1748-1716.1975.tb05903.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The renal response to a progressive isotonic extracellular volume (ECV) expansion was studied in 13 lambs of two age groups (5-28 days and 48-57 days). Changes in renal hemodynamics induced by the ECV expansion were followed. Intrarenal blood flow was determined by the microsphere method. For determination of the glomerular filtration rate (GFR) standard clearance techniques were used. Recordings were made during control conditions and when normal saline had been infused in amounts up to 4.5% of the body weight. During the infusion there was an increase in sodium excretion both in absolute values and in relationship to GFR. The increase was, however, much less pronounced in the younger lambs. The GFR did not change significantly during saline infusion. The cortical blood flow increased only in the older lambs. As a consequence the quotient between GFR and cortical blood flow decreased in the older lambs. The possibility of a causal relationship between the fall in filtration fraction so obtained and the more pronounced natriuretic response in the older lambs is discussed. The inner to outer cortical blood flow ratio increased more in the younger lambs during saline infusion. The functional significance of an age related blood flow redistribution is, however, not clear.
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Scheiner E. The relationship of antidiuretic hormone to the control of volume and tonicity in the human. Adv Clin Chem 1975; 17:1-52. [PMID: 165659 DOI: 10.1016/s0065-2423(08)60247-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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10
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Brown DC, DuBois M, Knock CA, Clarkson EM, De Wardener HE. Absence of antinatriferic and natriuretic activity in plasma ultrafiltrates (mol wt less than 50,000) and dialysates from volume-expanded dogs. Kidney Int 1974; 6:388-95. [PMID: 4216723 DOI: 10.1038/ki.1974.124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Sato K, Ullrich KJ. Serum-induced inhibition of isotonic fluid absorption by the kidney proximal tubule. I. Mechanism of inhibition. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 343:609-14. [PMID: 4407263 DOI: 10.1016/0304-4165(74)90279-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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12
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Aperia A, Broberger O. Renal control of salt and fluid homeostasis during i.v. saline infusion. ACTA PHYSIOLOGICA SCANDINAVICA 1974; 90:462-74. [PMID: 4823019 DOI: 10.1111/j.1748-1716.1974.tb05609.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Attallah AA, Lee JB. Radioimmunoassay of prostaglandin A. Intrarenal PGA2 as a factor mediating saline-induced natriuresis. Circ Res 1973; 33:696-703. [PMID: 4762010 DOI: 10.1161/01.res.33.6.696] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A highly specific, sensitive (25 pg) radioimmunoassay for prostaglandin A is described; the assay is characterized by high reproducibility (coefficient of variation 1-2%) and low cross-reactivity with respect to PGE
1
and PGE
2
(10%), PGB
2
(15%), and PGF
2α
(0.01%). High specificity for PGA was obtained by chromatographic separation of the prostaglandins. Since it has been suggested that PGA is a natriuretic "hormone," the concentration of PGA in the renal cortex, outer medulla, and papilla was determined in rabbits on low-sodium and high-sodium diets in the presence and the absence of the prostaglandin synthetase inhibitor indomethacin. In rabbits on the low-sodium diet (12 mEq/24 hours). PGA2 was 15 ± 4 pg/mg in the cortex, 502 ± 67 pg/mg in the outer medulla, and 3740 ± 640 pg/mg in the papilla. In rabbits on saline loading (56 mEq/24 hours), cortical and outer medullary PGA2 rose to 32 ± 6 pg/mg and 1275 ± 290 pg/mg, respectively, but papillary PGA decreased to 1842 ± 480 pg/mg. PGA concentration in the outer medulla and papilla was markedly inhibited by indomethacin (50 mg/day), and this inhibition was associated with sodium retention. The results indicated that sodium induced papillary synthesis of PGA and intrarenal circulation of the prostaglandin to the outer medulla and the cortex possibly via the long veins of the outer medulla occurred. The results are compatible with PGA
2
involvement in salineinduced natriuresis.
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Friborg J, Mousseau R, Brunette MG, Carrière S. [Intrarenal hemodynamic changes during acute isotonic saline loading in the dog (author's transl)]. Kidney Int 1973; 3:298-308. [PMID: 4792046 DOI: 10.1038/ki.1973.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Bennett WM, Bagby GC, Antonovic JN, Porter GA. Influence of volume expansion on proximal tubular sodium reabsorption in congestive heart failure. Am Heart J 1973; 85:55-64. [PMID: 4682006 DOI: 10.1016/0002-8703(73)90525-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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18
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Aperia A, Berg U, Broberger O. Control of sodium homeostasis in children with recurrent urinary tract infections and reduced glomerular filtration rates. ACTA PAEDIATRICA SCANDINAVICA 1971; 60:695-704. [PMID: 5123499 DOI: 10.1111/j.1651-2227.1971.tb07011.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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19
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Howards SS. Regulation of sodium excretion with special emphasis on the current status of natriuretic hormone. J Urol 1971; 105:749-52. [PMID: 4997079 DOI: 10.1016/s0022-5347(17)61622-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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22
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Wedeen RP, Goldstein M, Levitt MF. Mechanisms of edema and the use of diuretics. Pediatr Clin North Am 1971; 18:561-76. [PMID: 4939564 DOI: 10.1016/s0031-3955(16)32566-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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23
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Katz AI, Genant HK. Effect of extracellular volume expansion on renal cortical and medullary Na + -K + -ATPase. Pflugers Arch 1971; 330:136-48. [PMID: 4257772 DOI: 10.1007/bf00643030] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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25
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Flack JD, Ramwell PW, Shaw JE. Endocrinological implications of prostaglandins. CURRENT TOPICS IN EXPERIMENTAL ENDOCRINOLOGY 1971; 1:199-228. [PMID: 4350825 DOI: 10.1016/b978-0-12-153201-7.50013-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Fulop M, Brazeau P. Increased ureteral back pressure enhances renal tubular sodium reabsorption. J Clin Invest 1970; 49:2315-23. [PMID: 5480856 PMCID: PMC322732 DOI: 10.1172/jci106450] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Moderate increases of ureteral back pressure usually cause decreases of glomerular filtration rate and even greater decreases of sodium excretion. It has been assumed previously that increased ureteral back pressure does not enhance renal tubular sodium reabsorption directly and that the decreases of sodium excretion are caused by the decreases of glomerular filtration rate. In the experiments reported here, the effect of increased ureteral back pressure on urinary sodium excretion was studied in dogs in which changes of filtration rate were minimized by infusing saline while ureteral back-pressure was increased. When ureteral back pressure was increased on one side by 10-23 cm of water, the inulin clearance of the experimental kidney decreased by only 3-12% in 21 experiments, did not change significantly (+/-2%) in eight experiments, and increased by 3-8% in seven experiments. The sodium excretion of the experimental kidney decreased in all experiments regardless of whether its inulin clearance increased, decreased, or was unchanged from control values. When the inulin clearance of the experimental kidney increased or remained unchanged during increased ureteral back pressure, its reabsorption of sodium increased more than could be accounted for by the increase of filtered sodium. When the inulin clearance of the experimental kidney decreased during increased ureteral back pressure, its reabsorption of sodium decreased less than could be accounted for by the decrease of filtered sodium.Therefore, the effect of increased ureteral back pressure to decrease urinary sodium excretion is caused in part by increased tubular reabsorption of sodium.
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Aperia A, Broberger O, Feychting H. Effect of hypotonic mannitol and saline load on diluting capacity in man. ACTA PHYSIOLOGICA SCANDINAVICA 1970; 80:145-8. [PMID: 5475336 DOI: 10.1111/j.1748-1716.1970.tb04779.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Mills IH. Regulation of sodium excretion: intra- and extrarenal mechanisms. JOURNAL OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON 1970; 4:335-50. [PMID: 4948680 PMCID: PMC5367198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- I. H. Mills
- Professor of Medicine, Department of Investigative Medicine, University of Cambridge
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Liebau G, Müller R, Schad H, Edel HH. [Proximal tubular acidosis in patients with kidney transplants]. KLINISCHE WOCHENSCHRIFT 1970; 48:624-9. [PMID: 4932876 DOI: 10.1007/bf01485397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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30
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Buckalew VM, Martinez FJ, Green WE. The effect of dialysates and ultrafiltrates of plasma of saline-loaded dogs on toad bladder sodium transport. J Clin Invest 1970; 49:926-35. [PMID: 5441546 PMCID: PMC535765 DOI: 10.1172/jci106312] [Citation(s) in RCA: 81] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
In order to obtain direct evidence for the existence of a natriuretic hormone, dialysates and ultrafiltrates of plasma of dogs expanded with saline were tested for effects on sodium transport by the toad urinary bladder. Dialysate was obtained by dialysis of blood in vivo in a clinical dialyzer and by dialysis in vitro of small volumes of blood using a miniature model of the clinical dialyzer. Ultrafiltrates were prepared using selective molecular filters which permit passage of substances on the basis of molecular weight and three dimensional configuration. Dialysates and ultrafiltrates of hydropenic dogs caused a change in toad bladder potential difference of + 1% and in short circuit current of - 5%. In contrast, dialysates and ultrafiltrates from expanded dogs caused a change in potential difference of - 23% and in short circuit current of - 32%, a highly significant difference. Onset of reduction of short circuit current occurred within 3-5 min, reaching a maximum in 10-20 min. The effect was rapidly reversible, was specific for the serosal surface of the bladder, and could not be explained on the basis of nonspecific alterations in ionic composition or by dilutional effects. Ultrafiltrates of jugular vein plasma caused significantly more reduction of short circuit current than ultrafiltrates of femoral vein plasma. The data indicate the presence in plasma of saline-loaded dogs of a dialyzable inhibitor of toad bladder sodium transport. Ultrafiltrate studies using membranes of appropriate selectivity suggest the factor has a molecular weight of less than 3000.
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Davis BB, Knox FG, Wright FS, Howards SS. Effect of expansion of extracellular fluid volume on proximal sodium rabsorption in hyponatremic dogs. Metabolism 1970; 19:291-300. [PMID: 5435862 DOI: 10.1016/0026-0495(70)90127-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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32
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David DS, Grieco MH, Cushman P. Adrenal glucocorticoids after twenty years. A review of their clinically relevant consequences. JOURNAL OF CHRONIC DISEASES 1970; 22:637-711. [PMID: 5006493 DOI: 10.1016/0021-9681(70)90078-0] [Citation(s) in RCA: 157] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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33
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Bonjour JP, Peters G. Non-occurrence of a natriuretic factor in circulating blood of rats after expansion of the extracellular or the intravascular space. Pflugers Arch 1970; 318:21-34. [PMID: 5463914 DOI: 10.1007/bf00588540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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34
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Sealey JE, Kirshman JD, Laragh JH. Natriuretic activity in plasma and urine of salt-loaded man and sheep. J Clin Invest 1969; 48:2210-24. [PMID: 5355336 PMCID: PMC297478 DOI: 10.1172/jci106187] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The present study was designed to examine the question of whether or not there is a natriuretic hormonal substance involved in the renal regulation of sodium balance. For this purpose, procedures for concentration and fractionation of plasma and urine samples and a sensitive bioassay for demonstrating changes in renal sodium excretion were developed. The natriuretic assay utilized rats with mild diabetes insipidus which were maintained in salt and water balance. Using these approaches a natriuretic humoral substance was demonstrated in plasma and urine from normal man and sheep, and in patients with primary aldosteronism or essential hypertension. It seems likely that this substance participates in day to day regulation of sodium balance because it was not detectable in sodium-depleted subjects and it consistently appeared in the sodium-loaded subjects. The hormonal agent may not act immediately and its activity can be apparent for up to 3 hr. Full expression of its activity requires that the assay animals be appropriately volume expanded. This suggests that the increases in sodium excretion mediated by this hormonal substance depend in part on the coparticipation of other physical and perhaps humoral factors. This natriuretic substance appears to be of large molecular weight or carried by a large molecule. The data suggest that it acts, at least in part, to block sodium reabsorption in a more distal portion of the tubule.
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35
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The role of autonomous renal mechanisms in the control of sodium and water balance. Int Urol Nephrol 1969. [DOI: 10.1007/bf02425001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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36
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Hutchin P, Terzi RG, Hollandsworth LC, Johnson G, Peters RM. The influence of intravenous fluid administration on postoperative urinary water and electrolyte excretion in thoracic surgical patients. Ann Surg 1969; 170:813-23. [PMID: 5347558 PMCID: PMC1387660 DOI: 10.1097/00000658-196911000-00013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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37
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Suki WN, Martinez-Maldonado M, Rouse D, Terry A. Effect of expansion of extracellular fluid volume on renal phosphate handling. J Clin Invest 1969; 48:1888-94. [PMID: 5822594 PMCID: PMC322425 DOI: 10.1172/jci106155] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
To examine the specific effect of extracellular fluid (ECF) volume expansion on phosphate excretion studies were performed in thyroparathyroidectomized dogs receiving saline solution intravenously. The natriuresis resulting from ECF volume expansion was consistently accompanied by an increase in phosphate excretion. The possible role of increased filtered load of phosphate was eliminated in experiments in which the filtered load of phosphate was reduced by acute reduction in the glomerular filtration rate. Despite considerable reductions in filtered phosphate, ECF volume expansion resulted in a consistent increase in phosphate excretion. Furthermore, the possible contribution of alteration in blood composition was investigated in experiments in which saline was infused during thoracic inferior vena cava constriction. In these experiments saline infusion failed to increase sodium or phosphate excretion. Cessation of saline infusion and release of caval constriction resulted in a prompt natriuresis and increased phosphate excretion. It is concluded from these studies that extracellular fluid volume expansion results in an increased phosphate excretion in the parathyroidectomized dog. This effect is the specific consequence of ECF volume expansion and is not due to increase in the filtered load of phosphate or alterations in blood composition.
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Brenner BM, Falchuk KH, Keimowitz RI, Berliner RW. The relationship between peritubular capillary protein concentration and fluid reabsorption by the renal proximal tubule. J Clin Invest 1969; 48:1519-31. [PMID: 5796362 PMCID: PMC322379 DOI: 10.1172/jci106118] [Citation(s) in RCA: 236] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The relationship between peritubular capillary protein concentration and rate of sodium reabsorption by the rat proximal tubule was examined using free-flow recollection micropuncture techniques. Tubule fluid-to-plasma inulin ratios were measured before, during, and at successive intervals after brief (15-25 sec) intra-aortic injections (at the level of the renal artery) of colloid-free, isoncotic, and hyperoncotic solutions. Arterial hematocrit and protein concentrations were measured simultaneously in these rats. In other rats, total protein concentration of peritubular capillary blood plasma was determined before, during, and after these same infusions with a newly described submicroliter fiber-optic colorimeter. In the 15-25 sec interval necessary to infuse 2 ml of these test solutions, fractional and absolute sodium reabsorption varied directly with peritubular capillary colloid osmotic pressure, declining during infusion of colloid-free solutions, increasing during hyperoncotic infusions, and remaining unchanged during isoncotic infusions. In the subsequent 20-min interval after intra-aortic injection of these test solutions, capillary protein concentration remained at (isoncotic infusions) or returned to (colloid-free and hyperoncotic fluids) control values. Whereas reabsorption after colloid-free solutions returned to base line levels in parallel with the return in capillary protein concentration, after colloid infusions (which resulted in continued expansion of extracellular fluid volume), a progressive decline in reabsorption was observed. These results afford strong evidence that peritubular capillary colloid osmotic pressure is one important determinant of proximal sodium reabsorption. Nevertheless it is apparent that mechanisms other than or in addition to this must be invoked to explain the delayed inhibition of reabsorption that accompanies expansion of extracellular fluid volume by colloid solutions.
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Kaloyanides GJ, Cacciaguida RJ, Pablo NC, Porush JG. Increased sodium reabsorption in the proximal and distal tubule of caval dogs. J Clin Invest 1969; 48:1543-51. [PMID: 5796363 PMCID: PMC322381 DOI: 10.1172/jci106120] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The effects of water diuresis, hypotonic NaCl, and hypotonic mannitol diuresis on renal sodium and water excretion were examined in normal dogs and in dogs with chronic constriction of the thoracic inferior vena cava and ascites (caval dogs). During all three diuretic states, the capacity to excrete solute-free water relative to the supply of sodium to the water clearing segment of the nephron was significantly greater in the caval dog. This finding was most evident during hypotonic NaCl diuresis but was also striking during hypotonic mannitol diuresis despite the more unfavorable gradient for sodium reabsorption at the distal tubule produced by this agent in caval dogs. In addition, fractional distal sodium load was significantly smaller in caval dogs during water diuresis and could not be increased as readily as in normal dogs by hypotonic NaCl or mannitol infusion. The data indicate that fractional sodium reabsorption is increased at the water clearing segment and the proximal tubule in caval dogs. The differences in the pattern of free water clearance and tubular sodium transport between normal and caval dogs could not be easily explained by alterations in renal hemodynamics or aldosterone secretion. It is suggested that in the caval dog an alteration occurs in other factors which might influence renal tubular sodium transport, such as intrarenal hemodynamics, renal interstitial volume or pressure, or a natriuretic hormone, leading to increased tubular sodium reabsorption.
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Lee JB, Ferguson JF. Prostaglandins and natriuresis: the effect of renal prostaglandins on PAH uptake by kidney cortex. Nature 1969; 222:1185-6. [PMID: 5788989 DOI: 10.1038/2221185a0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Hayslett JP, Weinstein E, Kashgarian M, Epstein FH. Attempts to demonstrate a hormonal nattriuretic factor by micropuncture techniques. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 1969; 41:415-21. [PMID: 5803086 PMCID: PMC2591502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Buckalew VM, Puschett JB, Kintzel JE, Goldberg M. Mechanism of exaggerated natriuresis in hypertensive man: impaired sodium transport in the loop of Henle. J Clin Invest 1969; 48:1007-16. [PMID: 5771185 PMCID: PMC322315 DOI: 10.1172/jci106057] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
To evaluate the effects of saline loading on distal sodium reabsorption in hypertensive man, studies were performed during both water deprivation and water diuresis in eight hypertensive subjects, and the results were compared to data obtained from similar studies in normal subjects. All hypertensive patients exhibited an enhanced excretion of filtered sodium (C(Na)/C(In)) at any level of distal delivery of sodium compared to normal controls. Free water reabsorption (T(c) (H2O)) during hypertonic saline loading was quantitatively abnormal in the hypertensives at high levels of osmolar clearance (C(Osm)), and also the curve of T(c) (H2O) vs. C(Osm) leveled off above a C(Osm) of 18 ml/min per 1.73 m(2) in the hypertensive group in contrast to the normal controls in whom T(c) (H2O) showed no evidence of achieving an upper limit. Sodium depletion exaggerated the abnormality in T(c) (H2O) in hypertensives, and resulted in a positive free water clearance (C(H2O)) during hydropenia. During hypotonic saline loading in water diuresis, changes in free water clearance per 100 ml of glomerular filtrate (C(H2O)/C(In)) were less at any given increment in urine flow per 100 ml of glomerular filtrate (V/C(In)) in the hypertensives compared to normal controls (P < 0.001). This abnormality in C(H2O)/C(In) in the hypertensives in conjunction with the defect in T(c) (H2O) observed during hydropenia indicates that sodium reabsorption in the loop of Henle was abnormal at any given rate of distal delivery of sodium in hypertension. Furthermore, these abnormalities in T(c) (H2O) and C(H2O) coincided temporally with the development of the exaggerated natriuresis. Although the distal defect in sodium transport, in large part, accounted for the augmented natriuresis in hypertension, evidence was present also for enhanced rejection of sodium in the proximal tubule during saline loading in the hypertensives. Additional studies utilizing acetazolamide which increases distal delivery of sodium without extracellular fluid volume expansion showed only minimal abnormalities in C(H2O) in the hypertensive group, indicating that the defect in sodium transport in the loop of Henle in hypertensives is mainly an abnormal response to extracellular fluid expansion rather than an intrinsic defect in the loop to handle increased tubular loads of sodium. It is possible that the abnormality in sodium reabsorption in the loop of Henle is due to the transmission of the abnormally elevated blood pressure of the hypertensives to the medullary vasa recta during saline loading.
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Wright FS, Brenner BM, Bennett CM, Keimowitz RI, Berliner RW, Schrier RW, Verroust PJ, De Wardener HE, Holzgreve H. Failure to demonstrate a hormonal inhibitor of proximal sodium reabsorption. J Clin Invest 1969; 48:1107-13. [PMID: 5771192 PMCID: PMC322325 DOI: 10.1172/jci106067] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Recently, it has been reported that a humoral inhibitor of proximal sodium reabsorption could be detected in plasma, and dialysates of plasma, of rats and dogs undergoing saline diuresis. We have repeated these studies using similar techniques and protocols. Fractional sodium reabsorption by the proximal tubule (as estimated in free-flow micropuncture studies from tubule fluid-to-plasma inulin ratios) was found not to be lower during infusion of "natriuretic" plasma than during subsequent infusion of "hydropenic" plasma. Similarly, infusion of natriuretic plasma failed to prolong reabsorptive half-time of the shrinking drop beyond that seen during hydropenic plasma infusion. No increase in urine volume or rate of sodium excretion was observed during the period of natriuretic plasma infusion, nor did natriuretic plasma result in an increase in these measures in rats undergoing water diuresis. It also has been reported that dialysates of natriuretic plasma, but not of hydropenic plasma, when placed directly into the tubule lumen, inhibit proximal sodium reabsorption. In double blind studies carried out independently in Bethesda, London, and Cologne, we failed to detect the presence of a dialyzable inhibitor in natriuretic plasma. Finally, in contrast to other recent reports, we were unable to detect inhibitory activity in plasma obtained from dogs during the "escape" phase of chronic deoxycorticosterone acetate administration.
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Gill JR, Casper AG. Role of the sympathetic nervous system in the renal response to hemorrhage. J Clin Invest 1969; 48:915-22. [PMID: 5780201 PMCID: PMC322300 DOI: 10.1172/jci106050] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In 12 studies, a femoral artery and vein of a donor dog treated with desoxycorticosterone were connected by tubing to a renal artery and vein of a recipient dog treated with desoxycorticosterone, and the kidney with its nerve supply intact was perfused at femoral arterial pressure. Infusion of normal saline, which contained albumin, from 2.7 to 3.1 g/100 ml, in the donor produced significant natriuresis in a kidney of the donor (from 112 to 532 muEq/min) and in the perfused kidney (from 60 to 301 muEq/min) of the recipient. Increased sodium excretion in the perfused kidney was associated with an increase in the clearances of inulin and para-aminohippurate (P < 0.01) and a decrease in hematocrit of perfusing blood (P < 0.01). Infusion was continued in the donor while recipient was bled 23 ml/kg, with a decrease in mean arterial pressure from 152 to 130 mm Hg. Sodium excretion in perfused kidney decreased from 301 to 142 muEq/min (P < 0.01), whereas sodium excretion in donor was unchanged (506 VS. 532 muEq/min; P > 0.3). Clearance of inulin by perfused kidney was not significantly affected by bleeding (26 +/-SE 2 VS. 25 +/-SE 2; P > 0.2), but the clearance of para-aminohippurate was decreased by bleeding (P < 0.01), so that filtration fraction increased. As the perfused kidney of the recipient dog continued to receive blood from the natriuretic donor dog when the recipient dog was bled, the decrease in sodium excretion that bleeding produced in the perfused kidney was presumably mediated by renal nerves. Thus, an increase in nervous stimuli to the kidney that is not sufficient to decrease glomerular filtration rate can increase the tubular reabsorption of sodium and thereby significantly decrease its excretion. This property of the sympathetic nervous system to affect tubular reabsorption of sodium suggests that an increase in sympathetic activity may constitute an important mechanism for the renal conservation of sodium when intravascular volume is contracted by hemorrhage or other cause.
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Bank N, Koch KM, Aynedjian HS, Aras M. Effect of changes in renal perfusion pressure on the suppression of proximal tubular sodium reabsorption due to saline loading. J Clin Invest 1969; 48:271-83. [PMID: 5765784 PMCID: PMC322218 DOI: 10.1172/jci105983] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Rapid intravenous infusion of saline is known to suppress reabsorption of sodium and water in the proximal tubule. It has previously been shown that this suppression is accompanied by two changes which in combination might account for the over-all decrease in reabsorption: a reduction in the intrinsic reabsorptive capacity of the tubular epithelium (C/pir(2)) and a reduction in the ratio between tubular volume and GFR (pir(2)d/V(o)). The present micropuncture experiments were carried out in order to study the possible role of altered peritubular physical forces (hydrostatic and colloid oncotic pressure) in mediating these two changes. Proximal tubular reabsorptive capacity, transit time, fractional reabsorption of sodium and water, pir(2)d/V(o), and intratubular hydrostatic pressure were measured in saline-loaded rats during acute changes in renal perfusion pressure induced by intermittent constriction of the abdominal aorta. We found that when renal perfusion pressure was lowered to 70-90 mm Hg, the usual effects of saline loading on C/pir(2), pir(2)d/V(o), and fractional reabsorption in the proximal tubule were greatly minimized. When the aortic clamp was released and renal perfusion pressure allowed to rise, C/pir(2), pir(2)d/V(o), and fractional reabsorption fell markedly to levels characteristically seen in saline diuresis. Reclamping of the aorta reversed all of these changes. In order to determine whether the changes in C/pir(2) accompanying changes in renal perfusion pressure were mediated by a circulating natriuretic hormone, we assayed in hydopenic rats the dialysate of plasma collected from saline-loaded rats during and after release of aortic constriction by the split oil drop method. No significant difference in reabsorptive half-time (t(1/2)) was found between the two dialysates, and t(1/2) with both dialysates was approximately the same as was found when isotonic saline was injected in the tubules of hydropenic control animals. These observations suggest that the large changes in C/pir(2) which occurred with changes in renal perfusion pressure in saline-loaded rats were not mediated by a circulating hormone. We suggest that the reduction in C/pir(2), pir(2)d/V(o), and fractional reabsorption which occurs in the proximal tubule during a saline diuresis is related to the rise in hydrostatic pressure within the kidney.
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Vereerstraeten P, Toussaint C. Effects of plasmapheresis on renal hemodynamics and sodium excretion in dogs. Pflugers Arch 1969; 306:92-102. [PMID: 5813437 DOI: 10.1007/bf00586613] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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