Applied Renal Physiology in the PICU

2014 ◽  
pp. 129-146
Author(s):  
Ravi S. Samraj ◽  
Rajit K. Basu
Keyword(s):  
Renal Physiology

Renal Physiology

1976 ◽  
Vol 38 (1) ◽  
pp. 7-8
Author(s):  
G Giebisch
Keyword(s):  
Renal Physiology

Platelet-activating factor and the kidney

1986 ◽  
Vol 251 (1) ◽  
pp. F1-F11 ◽  
Author(s):  
D. Schlondorff ◽  
R. Neuwirth
Keyword(s):  
De Novo ◽  
Mesangial Cells ◽  
Biological Activities ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Initial Step ◽  
Renal Physiology ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Isolated Kidney

Platelet-activating factor (PAF) represents a group of phospholipids with the basic structure of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine. A number of different cells are capable of producing PAF in response to various stimuli. The initial step of PAF formation is activation of phospholipase A2 in a calcium-dependent manner, yielding lyso-PAF. During this step arachidonic acid is also released and can be converted to its respective cyclooxygenase and lipoxygenase products. The lyso-PAF generated is then acetylated in position 2 of the glycerol backbone by a coenzyme A (CoA)-dependent acetyltransferase. An additional pathway may exist whereby PAF is generated de novo from 1-alkyl-2-acetyl-sn-glycerol by phosphocholine transferase. PAF inactivation in cells and blood is by specific acetylhydrolases. PAF exhibits a variety of biological activities including platelet and leukocyte aggregation and activation, increased vascular permeability, respiratory distress, decreased cardiac output, and hypotension. In the kidney PAF can produce decreases in blood flow, glomerular filtration, and fluid and electrolyte excretion. Intrarenal artery injection of PAF may also result in glomerular accumulation of platelets and leukocytes and mild proteinuria. PAF increases prostaglandin formation in the isolated kidney and in cultured glomerular mesangial cells. PAF also causes contraction of mesangial cells. Upon stimulation with calcium ionophore the isolated kidney, isolated glomeruli and medullary cells, and cultured mesangial cells are capable of producing PAF. The potential role for PAF in renal physiology and pathophysiology requires further investigation that may be complicated by 1) the multiple interactions of PAF, prostaglandins, and leukotrienes and 2) the autocoid nature of PAF, which may restrict its action to its site of generation.

scholarly journals Renal Manifestations of Covid-19: Physiology and Pathophysiology

2021 ◽  
Vol 10 (6) ◽  
pp. 1216
Author(s):  
Zaher Armaly ◽  
Safa Kinaneh ◽  
Karl Skorecki
Keyword(s):  
Viral Replication ◽  
Virus Disease ◽  
Multiorgan Failure ◽  
Critical Role ◽  
Kidney Injury ◽  
Small Sample ◽  
Renal Physiology ◽  
High Morbidity ◽  
Enzymatic Production ◽  
High Incidence

Corona virus disease 2019 (COVID-19) imposes a serious public health pandemic affecting the whole world, as it is spreading exponentially. Besides its high infectivity, SARS-CoV-2 causes multiple serious derangements, where the most prominent is severe acute respiratory syndrome as well as multiple organ dysfunction including heart and kidney injury. While the deleterious impact of SARS-CoV-2 on pulmonary and cardiac systems have attracted remarkable attention, the adverse effects of this virus on the renal system is still underestimated. Kidney susceptibility to SARS-CoV-2 infection is determined by the presence of angiotensin-converting enzyme 2 (ACE2) receptor which is used as port of the viral entry into targeted cells, tissue tropism, pathogenicity and subsequent viral replication. The SARS-CoV-2 cellular entry receptor, ACE2, is widely expressed in proximal epithelial cells, vascular endothelial and smooth muscle cells and podocytes, where it supports kidney integrity and function via the enzymatic production of Angiotensin 1-7 (Ang 1-7), which exerts vasodilatory, anti-inflammatory, antifibrotic and diuretic/natriuretic actions via activation of the Mas receptor axis. Loss of this activity constitutes the potential basis for the renal damage that occurs in COVID-19 patients. Indeed, several studies in a small sample of COVID-19 patients revealed relatively high incidence of acute kidney injury (AKI) among them. Although SARS-CoV-1 -induced AKI was attributed to multiorgan failure and cytokine release syndrome, as the virus was not detectable in the renal tissue of infected patients, SARS-CoV-2 antigens were detected in kidney tubules, suggesting that SARS-CoV-2 infects the human kidney directly, and eventually induces AKI characterized with high morbidity and mortality. The mechanisms underlying this phenomenon are largely unknown. However, the fact that ACE2 plays a crucial role against renal injury, the deprivation of the kidney of this advantageous enzyme, along with local viral replication, probably plays a central role. The current review focuses on the critical role of ACE2 in renal physiology, its involvement in the development of kidney injury during SARS-CoV-2 infection, renal manifestations and therapeutic options. The latter includes exogenous administration of Ang (1-7) as an appealing option, given the high incidence of AKI in this ACE2-depleted disorder, and the benefits of ACE2/Ang1-7 including vasodilation, diuresis, natriuresis, attenuation of inflammation, oxidative stress, cell proliferation, apoptosis and coagulation.

scholarly journals Beyond a Passive Conduit: Implications of Lymphatic Biology for Kidney Diseases

2020 ◽  
Vol 31 (6) ◽  
pp. 1178-1190 ◽  
Author(s):  
Daniyal J. Jafree ◽  
David A. Long
Keyword(s):  
Kidney Disease ◽  
Therapeutic Potential ◽  
Kidney Diseases ◽  
Transplant Rejection ◽  
Lymphatic Vessels ◽  
Renal Physiology ◽  
Clear Fluid ◽  
Adult Kidney ◽  
And Function ◽  
Development Structure

The kidney contains a network of lymphatic vessels that clear fluid, small molecules, and cells from the renal interstitium. Through modulating immune responses and via crosstalk with surrounding renal cells, lymphatic vessels have been implicated in the progression and maintenance of kidney disease. In this Review, we provide an overview of the development, structure, and function of lymphatic vessels in the healthy adult kidney. We then highlight the contributions of lymphatic vessels to multiple forms of renal pathology, emphasizing CKD, transplant rejection, and polycystic kidney disease and discuss strategies to target renal lymphatics using genetic and pharmacologic approaches. Overall, we argue the case for lymphatics playing a fundamental role in renal physiology and pathology and treatments modulating these vessels having therapeutic potential across the spectrum of kidney disease.

scholarly journals A National Course for Renal Fellows: The Origins of Renal Physiology

2008 ◽  
Vol 19 (4) ◽  
pp. 649-650 ◽  
Author(s):  
Mark Zeidel ◽  
Joseph Bonventre ◽  
John Forrest ◽  
Vikas Sukhatme
Keyword(s):  
Renal Physiology

Adrenal and Renal Physiology, and Medical Renal Disease

2009 ◽  
Vol 182 (4) ◽  
pp. 1415-1415
Author(s):  
W. Scott McDougal
Keyword(s):  
Renal Disease ◽  
Renal Physiology

scholarly journals Role of the extracellular cAMP-adenosine pathway in renal physiology

2001 ◽  
Vol 281 (4) ◽  
pp. F597-F612 ◽  
Author(s):  
Edwin K. Jackson ◽  
Raghvendra K. Dubey
Keyword(s):  
Adenosine Receptors ◽  
Epithelial Transport ◽  
Receptor Activation ◽  
Hormonal Control ◽  
Renal Physiology ◽  
Tight Coupling ◽  
Extracellular Adenosine ◽  
Mediated Effects ◽  
Extracellular Camp

Adenosine exerts physiologically significant receptor-mediated effects on renal function. For example, adenosine participates in the regulation of preglomerular and postglomerular vascular resistances, glomerular filtration rate, renin release, epithelial transport, intrarenal inflammation, and growth of mesangial and vascular smooth muscle cells. It is important, therefore, to understand the mechanisms that generate extracellular adenosine within the kidney. In addition to three “classic” pathways of adenosine biosynthesis, contemporary studies are revealing a novel mechanism for renal adenosine production termed the “extracellular cAMP-adenosine pathway.” The extracellular cAMP-adenosine pathway is defined as the egress of cAMP from cells during activation of adenylyl cyclase, followed by the extracellular conversion of cAMP to adenosine by the serial actions of ecto-phosphodiesterase and ecto-5′-nucleotidase. This mechanism of extracellular adenosine production may provide hormonal control of adenosine levels in the cell-surface biophase in which adenosine receptors reside. Tight coupling of the site of adenosine production to the site of adenosine receptors would permit a low-capacity mechanism of adenosine biosynthesis to have a large impact on adenosine receptor activation. The purposes of this review are to summarize the physiological roles of adenosine in the kidney; to describe the classic pathways of renal adenosine biosynthesis; to review the evidence for the existence of the extracellular cAMP-adenosine pathway; and to describe possible physiological roles of the extracellular cAMP-adenosine pathway, with particular emphasis on the kidney.

Sign in / Sign up

Export Citation Format

Share Document