|
|
Year : 2007 | Volume
: 18
| Issue : 4 | Page : 512-522 |
|
Nephrotic Proteinuria and the Autonomic Nervous System |
|
Marcello Camici
Internal Medicine Department, Pisa University, Italy
Click here for correspondence address and email
|
|
 |
|
Abstract | | |
Nephrotic proteinuria triggers off complex neuro-endocrine mechanisms where forebrain activation results in sympathetic over activity. An attempt is made to discuss and analyze the renal sympathetic efferent nerve hyperactivity, the role played by the angiotensin/nitric oxide system during proteinuria and the nitric oxide/angiotensin imbalance in the hypothalamus. Several questions arise: further experimental and clinical studies are necessary. The answers to these questions may disclose new clinical and therapeutic perspectives for the nephrotic syndrome. Keywords: Brain, Proteinuria, Nephrotic Edema, Sympathetic Over activity
How to cite this article: Camici M. Nephrotic Proteinuria and the Autonomic Nervous System. Saudi J Kidney Dis Transpl 2007;18:512-22 |
Introduction | |  |
Both the over fill and under fill hypotheses of nephrotic edema, emphasize the importance of circulatory plasma volume (filling) as the main pathogenetic mechanism for edema genesis [Figure - 1].[1],[2] In the under fill theory, secondary renal sodium retention develops to compensate circulatory volume contraction (circulatory under filling), whereas in over fill theory, the abnormality leading to nephrotic edema is a primary renal sodium retention and consequent plasma volume expansion (circulatory over filling): a unifying hypothesis has been also proposed. [3],[4],[5]
Maintenance of physiologically constant extra cellular osmolarity and sodium concentration depends on a precise balance between intake and excretion of sodium and water (body sodium and volume homeostasis). The kidney plays a key role not only in the physiologic maintenance of body sodium and water homeostasis but also during edematous states such as the nephrotic syndrome (NS). In sodium-retaining disorders, extra-renal mechanisms such as neuro-endocrine manifesttations are also important.
Variations in the composition of blood plasma are picked up in the brain by the small areas that lack a blood-brain barrier. These areas, the circumventricular organs, surround the ventricular system. Three of these are involved in body fluid homeostasis: the subfornical organ (SFO), organum vasculosum laminae terminalis (OVLT), both of which are located in the anteroventral third ventricle, and the area postrema (AP), which is located at the transition of the fourth ventricle and the central canal of spinal cord.[6],[7] Increases in the effective osmolality of plasma are known to activate neurons in the OVLT[8] and, lesions of the OVLT markedly attenuate the stimulation of thirst and neurohypophyseal secretion of vasopressin (VP) and oxytocin (OT) by hyperosmolality in rats,[9] thus indicating the importance of the forebrain in mediating these adaptive responses.
How important is the forebrain activation by autonomic nervous system into the course of nephrotic edema? The purpose of this article is to provide new insights about body sodium/volume homeostasis and neuro-endocrine mechanisms during nephrotic proteinuria: it is useful to consider the neuro-endocrine manifestations of the NS in terms of their peripheral versus central origins. After nephrotic proteinuria, a number of vasoactive and neuro-active humural factors are released;[10],[11] angiotensin II, cytokines, nitric oxide (NO) and sympathetic nervous system activation. The present article is focused on the new insights about potential underlying mechanisms by which the above neuroactive humoral factors may contribute to the pathogenesis of nephrotic edema.
Sympathetic Nervous System and the Kidney | |  |
The kidneys have a dense afferent sensory and efferent sympathetic innervation. Neural sympathetic control of the kidney is at the level of the vessels, the tubules and the juxtaglomerular cells. [12],[13] In experimental studies, by using electrical stimulation to the efferent renal sympathetic nerves at frequencies just below the threshold for causing a decrease in renal blood flow, it was shown that a reversible decrease in urinary sodium excretion occurred in the absence of changes in glomerular filtration rate, renal blood flow and arterial pressure. [14]
Additional experiments demonstrated that this effect occurred in the proximal convoluted tubule, the thick ascending limb of Henle's loop, the distal convoluted tubule and the collecting duct and was caused by the release of norepinephrine from renal sympathetic nerve terminals with stimulation of post-synaptic alpha 1 adreno-receptors.[15],[16],[17]
Functionally specific renal sympathetic nerve fibers regulate the functions of tubules, renal blood vessels and juxtaglomerular granular cells; [12] increase in renal sympathetic nerve activity (RSNA) produces increase in renin secretion rate, decrease in urinary sodium excretion by increasing renal tubular sodium reabsorption and decreasing renal blood flow [Figure - 2]. This differentiated regulation occurs via mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli (sympathetic inflow) to various reflex pathways, centrally at the level of interconnecttions between various central neuron pools and peripherally at the level of efferent fibers (sympathetic outflow) targeted at various effectors within the organ.
Therefore, this reflex arc can be origin as well as target of averactivity of SNS. Afferent signals from the diseased kidney are transmitted to the vasomotor control center in the forebrain and efferent signals of sympathoexcitation may operate in the kidney. In the forebrain (hypothalamus), afferent inhibittory and excitatory reflex activity may be modulated by endocrine and paracrine factors such as angiotensin II and NO.[18],[19],[20],[21]
Sympathetic Nervous System and Nephrotic Proteinuria | |  |
Increased noradrenaline secretion rates have been observed in patients with the NS and normal glomerular filtration rate. [22] In experimental NS, Aman and [23] colleagues showed that peripherally and centrally active sympatholytic drugs, significantly attenuate proteinuria in rats subtotally nephrectomized: this indicates that inhibition of sympathetic nerve activity (SNA) by itself is of structural and functional benefit in proteinuria. The exact mechanism involved in direct damage of the kidney by sympathetic activity has not been resolved. In many proteinuric renal diseases, podocyte injury is the first step in development of proteinuria: [24] adrenergic receptors seem to be present on podocytes, because adrenergic agonists can induce both calcium influx and ATP release which in turn can induce proliferation, at least in vitro. [25],[26] This direct effect of cathecolamines may lead to podocyte injury independent of their hemodynamic effects. In normotensive diabetic humans, moxonidine (sympathoplegic agent) reduces albuminuria without affecting blood pressure. [27]
In rats with nephrotic edema, one of the mechanisms that contributes to the increased renal sodium retention is an increased renal sympathetic nerve activity (RSNA)[17],[28] and this RSNA is dependent, in large part, on increased efferent RSNA. [29] In nephrotic rats, the cardiopulmonary baroreflex inhibition of efferent RSNA is decreased; the defect lies in the central portion of the reflex and this may contribute to the observed increase in efferent RSNA of nephrotic edema. [30],[31] The central neurons system alterations underlying this cardiac baroreflex defect have not been defined.
Angiotensin II and Cardiac Baroreflex Modulation in Nephrotic Proteinuria | |  |
In rats, physiologic alterations in endogenous angiotensin II (AGII) activity tonically influence basal level of peripheral RSNA and its cardiac baroreflex regulation;[20],[32] this interaction between RSNA and renin-angiotensin system have a key role in the control of renal function and may be peripheral (renal) and/or central (nervous system). [33] Intrarenal interaction may be at renal synaptic nerve terminals (presynaptic) where AGII has an important presynaptic action to facilitate and to optimize the release of norepinephrine from renal sympathetic nerve terminals as well as from the central nervous system (activity mediated by AGII-type A receptors). [34],[35] In experimental studies, the effects of increased renal sympathetic nerve activity on renal function are attenuated when the activity of renin angiotensin system is suppressed or antagonized with ACE inhibitors or AGIItype AT1 receptor antagonists and the effects on intrarenal administration of AGII are atenuated after renal denervation.[36],[37],[38] In humans, administration of angiotensin converting enzyme inhibitor (enalpril) and antagonist of AGII-type A1 receptor (losartan) reduces sympathetic hyperactivity in patients with chronic renal failure. [39]
Extrarenal interaction may be in the hypothalamus at the level of the normal circuit, that mediates baroreceptor control of sympathetic vasomotor outflow, the so-called circumventricular organs. They consist of the subfornical organ, organum vasculosum of the lamina terminalis, median eminence and area postrema, which seem to be major sites of action of circulating AGII in the CNS.[40],[41]
In rabbits and rats, AT1 receptors are localized to areas of the brain that are exposed to blood-borne AGII, such as the circumventricular organs, including the SFO, median eminence, vascular organ of the lamina terminalis, anterior pituitary and area postrema in the hind brain.[42],[43] Not only circulating AGII, but also AGII of CNS origin may interact with SNS and it seems that there is a differential modulation of baroreflex control by neuron-versus glia-derived AG II. [32] The precise nature by which brain AGII participates in the regulation of sympathetic outflow is still not completely understood; firstly because the physiologic central neural circuit mediating baroreceptor reflex is not clearly known, [44] secondly because the basic physiologic autocrine, paracrine and endocrine effects of AGII are not completely understood [45] and thirdly because the molecular basis of arterial baroreceptor mechanotransduction is poorly understood. [46] What are the factors that link AT2 subtype AGII receptor, AGIII-AGIV fragments, epithelial sodium channels subunits (ENaC) and modulation of sympathetic tone inside neuronal tissue? In AT2-receptor "knockout" mice, deletion of AT2 receptor gene results in raised blood pressure and enhanced sensitivity to the receptor effects of AGII. [47] This suggests that the AT2 receptor mediates a vasodepressor effect and may functionally oppose the effects mediated by the AT1 receptor, possibly via bradykinin and nitric oxide (NO). [48] In human adult, AT2 receptors are present in the brain, heart, adrenal medulla, kidney and reproducetive tissues [Figure - 3]: [49] in the human brain, AGII receptor have been identified and characterized. [50],[51]
What is the link between AT2 subtype AGII receptors expression in neuronal forebrain tissue and, increased RSNA in nephrotic edema? While most interest has focused on forebrain circumventricular actions, areas of the brainstem such as the nucleus of the solitary tract and the ventrolateral medulla contain high concentrations of AT1 receptors: activetion of these receptors acutely incrases RSNA and RSNA baroreflex responses.[52]
Role of Nitric Oxide in Angiotensin-induced Cardiac Baroreflex Depression and Increased Efferent Renal Sympathetic Nerve Activity in Nephrotic Proteinuria | |  |
Cardiac baroreflex depression
Adenoviral vector demonstrates that AGII-induced depression of the cardiac baroreflex is mediated by NO released by endothelial NO synthase (eNOS or NOS III) in the nucleus tractus solitarii (NTS) of the rat. [53] Importantly, this action of AGII is mediated by NO itself, rather thanperoxynitrate, because adenoviral over expression of catalase, an enzyme that destroyes reactive oxygen species, did not affect the action of AGII in the NTS: [54] peroxynitrate is a product of the reaction between NO and superoxide, may affect release of transmitters (such as glutamate, GABA and achetylcoline) independent of NO. [55] In experimental models, central infusion of AGII has been shown to decrease neuronal NOS gene expression in the brainstem [56] (NTS; the brainstem termination site for baroreceptor afferents). Among direct vascular effects of angiotensin, there is the activation of nicotinamide-adeninedinucleotide phosphate oxidase (vascular NADPHase) and generation of superoxide anions,[57],[58] with oxygen-radical induced degradation of NO: [59] there is a subsequent decreased NO bioactivity. So, a first hypothetical explanation for cardiac baroreflex depression in the NS may be an increase in oxidative stress in the hypothalamus (brainstem) caused by AGII via cerebral vascular smooth muscle NADPH oxidase activation ([Figure - 4], Hypotheses A).
NO is a ubiquitous messenger molecule, which is involved in regulation of numerous biological functions. It is produced from stereospecific oxidation of L-arginine by a family of enzymes known as NO-synthase (NOS) (nNOS: neuronal NOS or NOS I; iNOS: inducible NOS or NOS II; eNOS: endothelial NOS or NOSIII. [60] NO is well recognized as an endogenous neuro-transmitter, neuro-mudulator and inter and intracellular messenger for signalling transduction. It has become clear that endogenous NO might be implicated in control of heart rate, acting at multiple sites including visceral afferents,[61] brainstem neurons that mediate cardiovascular reflexes,[62] cardiac and renal autonomic ganglia.[63],[64],[65],[66],[67],[68],[69] Thus, a second hypothetical explanation for cardiac baroreflex depression in the NS may be activation in the nucleus tracti solitarii (NTS) by AGIItype 1 receptor (AT1) of vascular cerebral eNOS and subsequent NO diffusion outside cerebral vascular system to nearby GABA ergic- NTS inter-neurons to enhance inhibition of neurons mediating the baroreceptor reflex in the NTS [70] ([Figure - 4] Hypotheses B).
Efferent RSNA increase
How can we link the decrease in cardiopulmonary baroreflex inhibition of efferent RSNA to the subsequent increase in efferent RSNA[29],[30],[31] and what is the explanation?
NO is a neurotransmitter at synapses in autonomic ganglia in peripheral nervous system: [71] NO produced by nNOS in proximity to the neuro-effector junction potentiates vagal transmission and decreases sympathetic transmission.[72],[73] The NO system is a natural anatgonist of cathecolamines. In rats, chronic PAN-induced NS results in down regulation of kidney iNOS and nNOS, vascular iNOS and brain nNOS: [74] so, it is possible that a reduction of NO as neurotransmitter occurs in close proximity to the neuro-effector junctions, with subsequent increase in renal sympathetic nerve activity. The down regulation of kidney iNOS and nNOS in chronic PAN-induced nephrotic rats seems to be linked to the proteinuria itself. [74]
This situation has been explored in experimental models. In chronic PAN-induced NS rats, proteinuria by itself seems to down regulate kidney iNOS and nNOS with subsequent deficiency of NO neurotransmission bioactivity and imbalance in renal parasympathetic/sympathetic activity [74] ([Figure - 5], kidney autonomic peripheral nervous system).
When the natural action of NO is reduced, normal or even low activity of the sympathetic nervous system can become detrimental for the kidney because of an imbalance between parasympathetic and sympathetic nervous system (autonomic dysfunction). This principle is already known for AGII. [75] An example is renal ablation. This model is associated with down regulation of iNOS and eNOS in the remnant kidney. [76]
Concluding Remarks
The autonomic nervous system plays an important physiologic role in the control of renal functions. In sodium- retaining disorders, such as the NS, there is over activity of the sympathetic nervous system and dysfunction of classic reflex autonomic arc: cardiac baroreflex depression and increased RSNA are expressions of this dysfunction.Clinical and experimental observations show that proteinuria is not merely a marker of chronic nephropathies but is also involved in the progression to end stage renal failure.After nephrotic proteinuria, forebrain (hypothalamus) activation is revealed by sympathetic hyperactivity, dependent in large part, on angiotensin II-induced cardiac baroreflex depression at forebrain level.
What is the role played by NO in this depression? What is the role of angiotensin peptides and their receptors? Will modulation of angiotensin/nitric oxide system at forebrain level influence the NS? These and related questions are fertile grounds for future studies in experimental NS.
References | |  |
1. | Humphreys MH. Mechanisms and management of nephrotic edema. Kidney Int 1994;45:266-81. [PUBMED] |
2. | Palmer BF, Alpern RJ. Pathogenesis of edema formation in the nephrotic syndrome Kidney Int (Suppl) 1997;59: S21-7. |
3. | Geers AB, Koomans HA, Boer P, Dorhout Mees EJ. Plasma and blood volumes in patients with the nephrotic syndrome. Nephron 1984;38:170-3. [PUBMED] |
4. | Schrier RW, Fassett RG. A critique of the overfill hypothesis of sodium and water retention in the nephrotic syndrome. Kidney Int 1998;53:1111-7. [PUBMED] [FULLTEXT] |
5. | Rodriguez-Iturbe B ,Herrera-Acosta J, Johnson RJ. Interstitial inflammation, sodium retention, and the pathogenesis of nephrotic edema: A unifying hypothesis. Kidney Int 2002;62:1379-84. |
6. | Skott O. Body sodium and volume homeostasis Am J Physiol Regul Integr Comp Physiol 2003;285:R14-8. |
7. | Fitzsimons JT. Angiotensin, thirst and sodium appetite. Physiol Rev 1998;78: 583-6. [PUBMED] [FULLTEXT] |
8. | Oldfield BJ, Badoer E, Hards DK, McKinley MJ. Fos production in retrogradely labeled neurons in the lamina terminalis following intravenous infusion of either hypertonic saline or angiotensin II. Neuroscience 1994;60:255-62. [PUBMED] [FULLTEXT] |
9. | Thrasher TN, Keil LC, Ramsay DJ. Lesions of the organum vasculosum of the lamina terminalis (OVLT) attenuate osmotically-induced drinking and vasopressin secretion in the dog. Endocrinology 1982;110:1837-9. [PUBMED] |
10. | Remuzzi G, Bertani T. Pathophysiology of progressive nephropathies. New Engl J Med 1998;12:1448-56. |
11. | Eddy AE. Proteinuria and interstitial injury. Nephrol Dial Transpl 2004;19:277-81. |
12. | DiBona GF Neural control of the kidney: Functionally specific renal sympathetic nerve fibers. Am J Physiol Regul Integr Comp Physiol 2000;279:R1517-24. |
13. | DiBona GF Neural control of the kidney: past,present and future. Hypertension 2003;41:621-4. |
14. | Slick GL, Aguilera AJ, Zambraski EJ, DiBona GF, Kaloyanides GJ. Renal neuroadrenergic transmission. Am J Physiol 1975;229:60-5. [PUBMED] [FULLTEXT] |
15. | Bello-Reuss E,Trevino DL, Gottschalk CW. Effect of renal sympathetic nerve stimulation on proximal water and sodium reabsorption. J Clin Invest 1976;57:1104-7. |
16. | DiBona GF, Sawin LL. Effect of renal nerve stimulation on NaCl and H2O transport in Henle's loop of the rat. Am J Physiol 1982;243:F576-80. [PUBMED] [FULLTEXT] |
17. | DiBona GF, Kopp UC. Neural control of renal function. Physiol Rev 1997;77:75-197. [PUBMED] [FULLTEXT] |
18. | Zucker IH. Brain angiotensin II: new insights into its role in sympathetic regulation. Circ Res 2002;90:503-5. [PUBMED] [FULLTEXT] |
19. | Reid IA. Between ANGII, sympathetic nervous system and baroreceptor reflexes in regulation of blood pressure. Am J Physiol 1992;262:E763-78. [PUBMED] [FULLTEXT] |
20. | DiBona GF, Jones SY, Sawin LL. Effect of endogenous angiotensin II on renal nerve activity and its cardiac baroreflex regulation. J Am Soc Nephrol 1998;9: 1983-9. [PUBMED] |
21. | Zanzinger J, Czachurski J, Seller H. Inhibition of sympathetic vasoconstriction is a major principle of vasodilatation by nitric oxide in vivo. Circ Res 1994;75: 1073-7. [PUBMED] |
22. | Rahman SN, Abraham WT, Van Putten VJ, Hasbargen JA, Schrier RW. Increased norepinephrine secretion in patients with the nephrotic syndrome and normal glomerular filtration rates: evidence for primary sympathetic activation. Am J Nephrol 1993;13:266-70. [PUBMED] |
23. | Amann K, Rump LC, Simonavicience A, et al. Effects of low dose sympathetic inhibition on glomerulosclerosis and albuminuria in subtotally nephrectomized rats. J Am Soc Nephrol 2000;11:1469-78. |
24. | Ruotsalainen V, Ljunberg P, Wartiovaara J, et al. Nephrin is specifically located at the slit diaphragm of glomerular podocytes. Proc Natl Acad Sci USA 1999;96:7962-7. |
25. | Huber TB, Gloy J, Henger A, et al. Catecholamines modulate podocyte function. J Am Soc Nephrol 1998;9:335-45. [PUBMED] |
26. | Vonend O, Oberhauser V, von Kugelgen I, et al. ATP release in human kidney cortex and ist mitogenic effects in visceral glomerular epithelial cells. Kidney Int 2002;61:1617-26. |
27. | Strojek K, Grzeeszczak W, Gorska J. Lowering of microalbuminuria in diabetic patients by a sympathicoplegic agent: novel approach to prevent progression of diabetic nephropathy? J Am Soc Nephrol 2001;12:602-5. |
28. | DiBona GF, Sawin LL, Jones SY. Characteristics of renal sympathetic nerve activity in sodium-retaining disorders. Am J Physiol Regul Integr Comp Physiol 1996;271:R295-302. |
29. | Herman PJ, Sawin LL, DiBona GF. Role of renal nerves in renal sodium retention of nephrotic syndrome. Am J Physiol 1989;256:F823-9. [PUBMED] [FULLTEXT] |
30. | Neahring JC, Jones SY, DiBona GF. Cardiopulmonary baroreflex function in nephrotic rats. J Am Soc Nephrol 1995; 5:2082-6. [PUBMED] |
31. | Hinojosa-Laborde C, Jones SY, DiBona GF. Hemodynamics and baroreflex function in rats with nephrotic syndrome Am J Physiol 1994;267(4Pt2):R953-R964 |
32. | Sakai K, Chaplean MW, Marimoto S,Cassell MD, Sigmund CD. Differential modulation of baroreflex control of heart rate by neuron-vs.glia- derived angiotensin II. Physiol Genomics. 2004;20(1):66-72 |
33. | DiBona GF. Peripheral and central interactions between the renin-angiotensin system and the renal sympathetic system and the renal sympathetic nerves control of renal function Am.N.Y.Acad. Sci. 2001; 940:395-406 |
34. | Story DF, Ziogas J. Interaction of angiotensin II with noradrenergic transmission Trends Pharmacol. Science 1987;8:269-71 |
35. | Saxena PR. Interaction between the reninangiotensin-aldosterone and sympathetic nervous system. J Cradiovasc Pharmacol 1992;19:S80-8 |
36. | Handa RK, Johns EJ. Interaction of the renin-angiotensin system and the renal nerves in the regulation of rat kidney function. J Physiol 1985;369:311-21 [PUBMED] [FULLTEXT] |
37. | Wang PC, Bernard R, Timmermans PB. Effect of blocking angiotensin subtypes on rat sympathetic nerve function. Hypertension 1992;19:663-7 |
38. | Liu FY, Cogan MG. Angiotensin II stimulation of hydrogen secretion in the rat early proximal tubule J Clin Invest 1988;82:601-7 |
39. | Klein IH, Ligttenberg G, Oey PL. Enalpril and losartan reduce sympathetic hyperactivity in patients with chronic renal failure. J Am Soc Nephrol 2003;14:425-30 |
40. | Ferguson AV, Washburn DL. Angiotensin II: a peptidergic neurotransmitter in central autonomic pathways. Progr Neurobiol 1998;54:169-92 |
41. | Ferguson AV, Bains JS. Actions of angiotensin in the subfornical organ and area postrema: implications for longterm control of autonomic output. Clin Exp Pharmacol Physiol 1997;24:96-101 [PUBMED] |
42. | Song K, Allen AM, Paxinos G, Mendelsohn FA. Mapping of angiotensin II receptor subtype hetereogeneity in rat brain. J Comp Neurol 1992;316:467-84. [PUBMED] |
43. | Lenkei Z, Polkovits M, Corvol P, LlorensCortes C. Expression of angiotensin type-1 (AT1) and type-2 (AT 2) receptor mRNAs in the adult rat brain :a functional neuroanatomical review. Front Neuroendocrinol 1997;M18:383-439 |
44. | Sved AF, Sito CJ,Madden SD, Stocker SD, Yajima Y. Excitatory inputs to the RVLM in the context of the baroreceptor reflex. Ann New York Acad Sci 2001; 940:247-58 |
45. | Lim HS, Macfadyen RJ, Lip GY. Diabete mellitus, the renin angiotensin aldosterone system and the heart Arch Int Med 2004;164:1737-48. |
46. | Drummond HA, Welsh MJ, Abboud FM. ENaC subunits are molecular components of the arterial barorecptor complex. Ann New York Acad Sci 2001;94:42-7. |
47. | Hein L, Barsh GS, Pratt RE, Dzav VJ, Kobilka BK. Behavioural and cardiovascular effects of dysrupting the angiotensin II type-2 receptor in mice. Nature (London) 1995;377:744-7. |
48. | Siragy HM, Inagami T, Ichiki T, Carey RM. Sustained hyepersensitivity to angiotensin II and its mechanism in mice lacking the subtype-2 (AT2) angiotensin receptor. Proc Natl Acad Sci USA 1999;96:6506-10. [PUBMED] [FULLTEXT] |
49. | Zhuo J, Allen AM, Alcorn D, Aldred GP, MacGregory DP, Mendelsohn FA. The distribution of angiotensin II receptors In Hypertension: Pathophysiology, Diagnosis and Management. Laragh JH, Brenner BM, eds. Raven Press: New York, USA; 1995. p. 1739-62. |
50. | Barnes JM, Steward LJ, Barber PC, Barnes NM. Identification and characterrization of angiotensin II receptor subtypes in human brain. Eur J Pharmacol 1993; 230:251-8. [PUBMED] |
51. | MacGregor DP, Murone C, Song K, Allen AM, Paxinos G, Mendelsohn FA. Angiotensin II receptor subtypes in the human central nervous system. Brain Res 1995; 675:231-40. [PUBMED] [FULLTEXT] |
52. | Head GA, Majoroux DN. Central angiotensin and baroreceptor control of circulation. Ann New York Acad Sci 2001; 940:361-79. |
53. | Paton JF, Deuchars J, Ahmad Z, Wong LF, Murphy D, Kasparov S. Adenoviral vector demonstrates that angiotensin IIinduced depression of the cardiac baroreflex is mediated by endothelial nitric oxide synthase in the nucleus tractus solitarii of the rat. J Physiol 2001;531:445-58. [PUBMED] [FULLTEXT] |
54. | Wong LF. Genetic and phramacological dissection of pathways involved in the angiotensin II-mediated depression of baroreflex function. FASEB J 2002;16: 1595-601. |
55. | Ohkuma S, Katsura M. Nitric oxide and peroxynitrite as factors to stimulate neurotransmitter release in the CNS. Progr Neurobiol 2001;64:97-108. |
56. | Calapai G, Marciano ML, Costantino G, et al. Effects of water deprivation and angiotensin II intracerebroventricular administration on brain nitric oxide synthase activity. Eur J Phramacol 1998; 360:147-54. |
57. | Sowers JR. Hypertension, angiotensin II and oxidative stress. N Engl J Med 2002;346:1999-2001. [PUBMED] [FULLTEXT] |
58. | Ritz E, Haxsen V. Angiotensin II and oxidative stress: An unholy alliance. J Am Soc Nephrol 2003;14:2985-7. [PUBMED] [FULLTEXT] |
59. | Rathaus M, Bernheim J. Oxygen species in the microvascular environment: Regulation of vascular tone and development of hypretension. Nephrol Dial Trnplant 2002;17:216-21. |
60. | Kiechle FL, Malinski T. Nitric oxide: Biochemistry, pathophysiology and detection. Am J Clin Pathol 1993;100:567-75. [PUBMED] |
61. | Cohen AS. Nitric oxide regulates spike frequency accommodation in nodose neurons of the rabbit. Neurosc Lett 1994;173:17-20. |
62. | Lawrance AJ. Nitric oxide as a modulator of medullary pathways. Clin Exp Pharmacol Physiol 1997;24:760-3. |
63. | Paterson DJ. Nitric oxide and autonomic regulation of cardiac excitability. Exp Physiol 2001;86:1-12. |
64. | Massion PB, Feron O, Dessy C, Balligand JL. Nitric oxide and cardiac function. Ten years after and continuing. Circ Res 2003; |
65. | Majid DS, Navar LG. Nitric oxide in the control of renal hemodynamics and excretory function. Am J Hypertens 2001;14:74S-82S. [PUBMED] [FULLTEXT] |
66. | Kone BC, Naylis C. Biosynthesis and homeostatic roles of nitric oxide in the normal kidney. Am J Physiol 1997;272: F561-78. |
67. | Manning RD, Hu L. Nitric oxide regulates renal hemodynamics and urinary sodium excretion in dogs. Hypertension 1994; 23:619-25. |
68. | Stoos BA, Garvin JL. Actions of nitric oxide on renal epithelial transport Clin Exp Pharmacol Physiol 1997;24:591-4. |
69. | Weiss ML, Chowdhury SI, Patel KP, Kemey MJ, Huang J. Neural circuitry of the kidney: NO-containing neurons. Brain Res 2001;919:269-82. |
70. | Paton JF, Kasparov S. Baroreceptor reflex attenuation by angiotensin II and nitric oxide are both mediated by soluble guanylil cyclase in the nucleus tractus solitarii. J Physiol 2001;533:87. |
71. | Bennet MR. Nitric oxide release and long term potentiation at synapses in autonomic ganglia. Gen Pharmacol 1994;25:1541-51. |
72. | Herring N, Paterson DJ. Nitric oxidecGMP pathway facilitates acetylcholine release and bradicardia during vagal nerve stimulation in the guinea-pig in vitro. J Physiol 2001;535:507-18. [PUBMED] [FULLTEXT] |
73. | Schwarz P. Endogenous and exogenous nitric oxide inhibits norepinephrine release from rat heart sympathetic nerves. Circ Res 1995;77:841-8. |
74. | Ni Z, Vaziri ND. Downregulation of nitric oxide synthase in nephrotic syndrome: role of proteinuria Biochem Biophys Acta 2003;1638:129-37. |
75. | Meyer TW. Why we block angiotensin II? Kidney Int 2000;58:458-9. [PUBMED] [FULLTEXT] |
76. | Vaziri ND, Ni Z, Oveisi F, Liang K, Pandian R. Enhanced nitric oxide inactivation and protein nitration by reactive oxygen species in renal insufficiency. Hypertension 2002;39:135-41. [PUBMED] [FULLTEXT] |

Correspondence Address: Marcello Camici Internal Medicine Department, Pisa University Italy
 Source of Support: None, Conflict of Interest: None  | Check |
PMID: 17951936  
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5] |
|
This article has been cited by | 1 |
Cyclosporine A - Treated nephrotic children show impaired vasodilatation but no autonomic neuropathy |
|
| Czupryniak, A. and Kałuzyńska, A. and Półtorak-Krawczyk, A. and Ostrowski, B. and Wiȩcek, B. and Tkaczyk, M. | | Archives of Medical Science. 2010; 6(4): 573-577 | | [Pubmed] | |
|
|
 |
 |
|
|
|
|
|
|
Article Access Statistics | | Viewed | 6479 | | Printed | 77 | | Emailed | 0 | | PDF Downloaded | 541 | | Comments | [Add] | | Cited by others | 1 | |
|

|