Tubuloglomerular Feedback and Single Nephron Function After Converting Enzyme Inhibition in the Rat
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ANSWER KEY Integrative Sciences: Biological Systems B Body Fluid/Electrolytes and Kidney Systems
ANSWER KEY Integrative Sciences: Biological Systems B Body Fluid/Electrolytes and Kidney Systems Problem Set Review Monday, November 28, 2011 at 9 am Lecturer: Lisa M Harrison-Bernard, PhD I. Body Fluid Problems - Shifts of water between compartments What happens to the following 5 parameters: ECF volume? ICF volume? ECF osmolarity? Plasma protein concentration (PPC)? Blood pressure? A. Infusion of isotonic NaCl (isosmotic volume expansion) B. Diarrhea - loss of isotonic fluid (isosmotic volume contraction) C. Excessive NaCl intake - addition of NaCl (hyperosmotic volume expansion) D. Sweating in a desert - loss of water (hyperosmotic volume contraction) E. Syndrome of inappropriate antidiuretic hormone (SIADH) - gain of water (hypoosmotic volume expansion) F. Adrenocortical insufficiency - loss of NaCl (hypoosmotic volume contraction) Page 1 of 5 ECF ICF ECF PPC (g%) Blood Volume (L) Volume (L) Osmolarity Pressure (mOsm) (mmHg) A ⇑ ⇔ ⇔ ⇓ ⇑ B ⇓ ⇔ ⇔ ⇑ ⇓ C ⇑ ⇓ ⇑ ⇓ ⇑ D ⇓ ⇓ ⇑ ⇑ ⇓ E ⇑ ⇑ ⇓ ⇓ ⇑ F ⇓ ⇑ ⇓ ⇑ ⇓ Page 2 of 5 II. Starling Forces 1. At the afferent arteriolar end of a glomerular capillary, PGC is 45 mmHg, PBS is 10 mmHg, and πGC is 27 mmHg. What are the value and direction of the net ultrafiltration pressure? PUF = (PGC – PBS) – (πGC - πBS) PUF = (45 - 10 mmHg) – (27) = 8 mmHg favors filtration of fluid out of the glomerular capillary III. Renal Clearance, Renal Blood Flow, Glomerular Filtration Rate 2. To measure GFR: Infuse inulin intravenously until PIN is stable. Measure urine volume produced in a known period of time (urine flow). Measure PIN and UIN. Given the following: PIN = 0.5 mg/ml UIN = 60 mg/ml Urine flow = 1.0 ml/min Calculate GFR? GFR = CIN = (UIN)(UV) ÷ PIN GFR = (60 mg/ml) (1 ml/min) ÷ (0.5 mg/ml) = 120 ml/min 3. -
Renal Function in Primary Aldosteronism
RENAL FUNCTION IN PRIMARY ALDOSTERONISM Harriet P. Dustan, … , A. C. Corcoran, Irvine H. Page J Clin Invest. 1956;35(12):1357-1363. https://doi.org/10.1172/JCI103392. Research Article Find the latest version: https://jci.me/103392/pdf RENAL FUNCTION IN PRIMARY ALDOSTERONISM 1 By HARRIET P. DUSTAN, A. C. CORCORAN, AND IRVINE H. PAGE (From the Research Division of The Cleveland Clinic Foundation and The Frank E. Bunts Educational Institute, Cleveland, 0.) (Submitted for publication June 11, 1956; accepted August 9, 1956) Primary aldosteronism is characterized by weak- purate (PAH) and mannitol. Total renal vascular re- ness-a sequel to potassium loss; hypertension- sistance was calculated by the formula of Gomez (3). The functions of water conservation and electrolyte ex- attributed to sodium retention; thirst and polyuria; cretion were observed simultaneously. Water con- and excretion of dilute, alkaline urine (1). These servation was determined from the differences (TVio) defects imply significant changes in renal function. between urine flow (V) and osmolal clearance (Co..) The purpose of this report is to describe pre- (4) during osmotic diuresis in hydropenia (water depri- and postoperative observations of renal function vation for 16 or 24 hours and/or infusion of Pitressin@). The priming solution contained 260 mOsm. of mannitol in three patients suffering from aldosterone-se- and 0.6 gin. of PAH; the sustaining infusion supplied creting adrenal cortical tumors. about 3 mOsm. of mannitol and 15 mg. per PAH per min- The data indicate that excess urinary potassium ute. Urine formed during the first 20 minutes was dis- excretion is attributable to aldosteronism as such, carded; it was then collected from an indwelling urethral and may bear on the basic cellular mechanism of catheter at 3 to 6 successive intervals of about 10 min- action of aldosterone. -
Renal Hemodynamic and Metabolic Physiology in Normal Pregnancy
Obstetric Nephrology: Renal Hemodynamic and Metabolic Physiology in Normal Pregnancy Ayodele Odutayo and Michelle Hladunewich Summary Glomerular hyperfiltration, altered tubular function, and shifts in electrolyte-fluid balance are among the hallmark renal physiologic changes that characterize a healthy pregnancy. These adjustments are not only critical to maternal and fetal well being, but also provide the clinical context for identifying gestational aberrations in Divisions of Nephrology and renal function and electrolyte composition. Systemic vasodilation characterizes early gestation and produces Obstetric Medicine, increments in renal plasma flow and GFR, the latter of which is maintained into the postpartum period. In addition, Department of renal tubular changes allow for the accumulation of nutrients and electrolytes necessary for fetal growth such that Medicine, wasting of proteins, glucose, and amino acids in urine is limited in pregnancy and total body stores of electrolytes Sunnybrook Health increase throughout gestation. Substantial insight into the mechanisms underlying these complex adjustments can Sciences Centre, University of Toronto, be gleaned from the available animal and human literature, but our understanding in many areas remains Toronto, Ontario, incomplete. This article reviews the available literature on renal adaptation to normal pregnancy, including renal Canada function, tubular function, and electrolyte-fluid balance, along with the clinical ramifications of these adjust- ments, the limitations of the existing literature, and suggestions for future studies. Correspondence: Clin J Am Soc Nephrol 7: 2073–2080, 2012. doi: 10.2215/CJN.00470112 Dr. Michelle Hladunewich, Divisions of Nephrology, Critical Introduction clinically presents as a decrease in the serum creati- Care, and Obstetric Maternal accommodation to normal pregnancy begins nine. -
Glomerular Filtration I DR.CHARUSHILA RUKADIKAR Assistant Professor Physiology GFR 1
Glomerular filtration I DR.CHARUSHILA RUKADIKAR Assistant Professor Physiology GFR 1. Definition 2. Normal value 3. Variation 4. Calculation (different pressures acting on glomerular membrane) 5. Factors affecting GFR 6. Regulation of GFR 7. Measurement of GFR QUESTIONS LONG QUESTION 1. GFR 2. RENIN ANGIOTENSIN SYSTEM SHORT NOTE 1. DYNAMICS OF GFR 2. FILTRATION FRACTION 3. ANGIOTENSIN II 4. FACTORS AFFECTING GLOMERULAR FILTRATION RATE 5. REGULATION OF GFR 6. RENAL CLEARANCE TEST 7. MEASUREMENT OF GFR Collecting duct epithelium P Cells – Tall, predominant, have few organelles, Na reabsorption & vasopressin stimulated water reabsorption I cells- CT and DCT, less, having more cell organelles, Acid secretion and HCO3 transport CHARACTERISTICS OF RENAL BLOOD FLOW 600-1200 ml/min (high) AV O2 difference low (1.5 mL/dL) During exercise increases 1.5 times Low basal tone, not altered in denervated / innervated kidney VO2 in kidneys is directly proportional to RBF, Na reabsorption & GFR Not homogenous flow, cortex more & medulla less Vasa recta hairpin bend like structure, hyperosmolarity inner medulla Transplanted kidney- cortical blood flow show autoregulation & medullary blood flow don’t show autoregulation, so no TGF mechanism Neurogenic vasodilation not exist 20% of resting cardiac output, while the two kidneys make < 0.5% of total body weight. Excretory function rather than its metabolic requirement. Remarkable constancy due to autoregulation. Processes concerned with urine formation. 1. Glomerular filtration, 2. Tubular reabsorption and 3. Tubular secretion. • Filtration Fluid is squeezed out of glomerular capillary bed • Reabsorption Most nutrients, water and essential ions are returned to blood of peritubular capillaries • Secretion Moves additional undesirable molecules into tubule from blood of peritubular capillaries Glomerular filtration Glomerular filtration refers to process of ultrafiltration of plasma from glomerular capillaries into the Bowman’s capsule. -
Active Transport, Hematology, EKG and Urinalysis Author: Margaret T. F
FINAL PROBLEM SET: Integration of Material from 4 Labs; Active Transport, Hematology, EKG and Urinalysis Author: Margaret T. Flemming, MS, Department of Biology, Austin Community College, Austin, TX Objectives—after completing this problem set you should be able to: 1) calculate renal function values, showing your work 2) describe the relationship between cardiac and renal function 3) describe the relationship between blood values and urine values, including relevant information regarding secondary active transport of glucose by the renal tubules Background—Renal function calculations can give a good snapshot of a patient’s health, indicating possible circulatory problems, blood glucose problems, etc. But being able to do the calculations is only the first step. This problem set asks you to do calculations and then think critically to analyze results and come up with possible diagnoses. To successfully answer the critical thinking questions you will need to integrate what you know about renal function, active transport, and normal blood and urine values. In addition, you’ll need to bring in what you know about normal cardiac output (CO), renal fraction of CO and how the kidney adjust to changes in CO and blood pressure. Resources—Work in your regular lab groups of 3-4 students. Definitions and formulas are given to you, along with certain clinical values that were not obtained in labs. Chapters 5, 15 and 16 and 19 in your text (Human Physiology, Silverthorn, 4th Ed.), as well as in your notes for those chapters, provide the background information needed to answer the theoretical questions. Remember to limit your online searches to sites ending in edu, or sites of professional organizations, rather than commercial sites. -
Renal Effects of Atrial Natriuretic Peptide Infusion in Young and Adult ~Ats'
003 1-3998/88/2403-0333$02.00/0 PEDIATRIC RESEARCH Vol. 24, No. 3, 1988 Copyright O 1988 International Pediatric Research Foundation, Inc. Printed in U.S.A. Renal Effects of Atrial Natriuretic Peptide Infusion in Young and Adult ~ats' ROBERT L. CHEVALIER, R. ARIEL GOMEZ, ROBERT M. CAREY, MICHAEL J. PEACH, AND JOEL M. LINDEN WITH THE TECHNICAL ASSISTANCE OF CATHERINE E. JONES, NANCY V. RAGSDALE, AND BARBARA THORNHILL Departments of Pediatrics [R.L.C., A.R.G., C.E.J., B. T.], Internal Medicine [R.M.C., J.M. L., N. V.R.], Pharmacology [M.J.P.], and Physiology [J.M.L.], University of Virginia, School of Medicine, Charlottesville, Virginia 22908 ABSTRAm. The immature kidney appears to be less GFR, glomerular filtration rate responsive to atrial natriuretic peptide (ANP) than the MAP, mean arterial pressure mature kidney. It has been proposed that this difference UeC~pV,urinary cGMP excretion accounts for the limited ability of the young animal to UN,V, urinary sodium excretion excrete a sodium load. To delineate the effects of age on the renal response to exogenous ANP, Sprague-Dawley rats were anesthetized for study at 31-32 days of age, 35- 41 days of age, and adulthod. Synthetic rat A* was infused intravenously for 20 min at increasing doses rang- By comparison to the adult kidney, the immature kidney ing from 0.1 to 0.8 pg/kg/min, and mean arterial pressure, responds to volume expansion with a more limited diuresis and glomerular filtration rate, plasma ANP concentration, natriuresis (I). A number of factors have been implicated to urine flow rate, and urine sodium excretion were measured explain this phenomenon in the neonatal kidney, including a at each dose. -
Urate-2- C Transport in the Rat Nephron
Urate-2-14C transport in the rat nephron Ronald A. Kramp, … , William E. Lassiter, Carl W. Gottschalk J Clin Invest. 1971;50(1):35-48. https://doi.org/10.1172/JCI106482. Research Article Intrarenal transport of urate-2-14C was studied in anesthetized rats using the microinjection technic. During saline diuresis, small volumes of urate-2-14C (0.24-0.48 mM) and inulin-3H were injected into surface proximal and distal convoluted tubules, and ureteral urine was collected serially. Total (74-96%) and direct (57-84%) urate recovery increased significantly the more distal the puncture site. Delayed recovery (±20%) remained approximately the same regardless of localization of the microinjection. After proximal injections, total and direct recoveries of urate-2-14C were significantly higher in rats treated with probenecid, pyrazinoate, or PAH than during saline diuresis alone, while the excretion rates were comparable after distal injection. Delayed recovery was not altered by drug administration. The decreased proximal reabsorption of urate is presumably due to an effect of the drugs on the luminal membrane of the nephron. For perfusion at high urate concentrations, nonradioactive urate was added to the injectate (0.89-1.78 mM). Urate-2-14C recovery was almost complete and there was no delayed excretion, demonstrating saturation kinetics. These findings are compatible with a carrier-mediated mechanism for urate transport probably located at the luminal border of the proximal tubular epithelium. No definitive evidence for urate secretion was found in these studies. Find the latest version: https://jci.me/106482/pdf Urate-2-14C Transport in the Rat Nephron RONALD A. -
Renal Physiology and Pathophysiology of the Kidney
Renal Physiology and pathophysiology of the kidney Alain Prigent Université Paris-Sud 11 IAEA Regional Training Course on Radionuclides in Nephrourology Mikulov, 10–11 May 2010 The glomerular filtration rate (GFR) may change with - The adult age ? - The renal plasma (blood) flow ? + - The Na /water reabsorption in the nephron ? - The diet variations ? - The delay after a kidney donation ? IAEA Regional Training Course on Radionuclides in Nephrourology Mikulov, 10–11 May 2010 GFR can measure with the following methods - The Cockcroft-Gault formula ? - The urinary creatinine clearance ? - The Counahan-Baratt method in children? - The Modification on Diet in Renal Disease (MDRD) formula in adults ? - The MAG 3 plasma sample clearance ? IAEA Regional Training Course on Radionuclides in Nephrourology Mikulov, 10–11 May 2010 About the determinants of the renogram curve (supposed to be perfectly « BKG » corrected) 99m -The uptake (initial ascendant segment) of Tc DTPA depends on GFR 99m -The uptake (initial ascendant segment) of Tc MAG 3 depends almost only on renal plasma flow 123 -The uptake (initial ascendant segment) of I hippuran depends both on renal plasma flow and GFR -The height of renogram maximum (normalized to the injected activity) reflects on the total nephron number -The « plateau » pattern of the late segment of the renogram does mean obstruction ? IAEA Regional Training Course on Radionuclides in Nephrourology Mikulov, 10–11 May 2010 Overview of the kidney functions Regulation of the volume and composition of the body fluids -
Atrial Natriuretic Peptide and Blood Volume During Red Cell Transfusion
Archives ofDisease in Childhood 1991; 66: 395-397 395 Atrial natriuretic peptide and blood volume during Arch Dis Child: first published as 10.1136/adc.66.4_Spec_No.395 on 1 April 1991. Downloaded from red cell transfusion in preterm infants W Rascher, N Lingens, M Bald, 0 Linderkamp Abstract 1710 g (range 650-2660). All infants were in Because raised plasma concentrations of good clinical condition. Four were mechanically atrial natriuretic peptide indicate volume ventilated through an intratracheal tube. None expansion, we studied the effect of red cell had renal disease, shock, sepsis or were being transfusion on plasma atrial natriuretic pep- treated with diuretics. The volume of trans- tide concentration, packed cell volume, and fused red cells was calculated to raise the packed intravascular volume in eight preterm infants. cell volume to 0-45 (haemoglobin to 155 g/l). Red cell transfusion increased red cell mass, The transfusion rate averaged 0-05 (0 01) packed cell volume and erythrocyte count, ml/min/kg. but decreased plasma volume. Total blood Before and one hour after red cell transfusion volume, plasma atrial natriuretic peptide con- blood was drawn in EDTA coated tubes (1 5-2 centration, urine flow rate, and urinary ml) for determination of plasma atrial natriur- sodium excretion did not change. etic peptide and haemoglobin concentrations We conclude that a slow transfusion of packed cell volume, haemoglobin F concentra- less than 10 ml red cells/kg body weight does tion, and plasma osmolality. In addition 0 5 ml not cause volume expansion with subsequent blood was drawn in plastic tubes for measure- atrial natriuretic peptide release thereby ment of serum sodium, potassium and creati- affecting the cardiovascular system. -
Mechanism of the Antidiuretic Effect Associated with Interruption of Parasympathetic Pathways
Mechanism of the Antidiuretic Effect Associated with Interruption of Parasympathetic Pathways Robert W. Schrier, … , Tomas Berl, Judith A. Harbottle J Clin Invest. 1972;51(10):2613-2620. https://doi.org/10.1172/JCI107079. Research Article The present experiments were undertaken to investigate the mechanism whereby the parasympathetic nervous system may be involved in the renal regulation of solute-free water excretion. The effects of interruption of parasympathetic pathways by bilateral cervical vagotomy were examined in eight normal and seven hypophysectomized anesthetized dogs undergoing a water diuresis. In the normal animals cervical vagotomy decreased free-water clearance (C ) from H2O 2.59±0.4 se to −0.26±0.1 ml/min (P < 0.001), and urinary osmolality (Uosm) increased from 86±7 to 396±60 mOsm/kg (P < 0.001). This antidiuretic effect was not associated with changes in cardiac output, renal perfusion pressure, glomerular filtration rate, renal vascular resistance, or filtration fraction and was not affected by renal denervation. A small but significant increase in urinary sodium and potassium excretion was observed after vagotomy in these normal animals. Pharmacological blockade of parasympathetic efferent pathways with atropine, curare, or both was not associated with an alteration in either renal hemodynamics or renal diluting capacity. In contrast to the results in normal animals, cervical vagotomy was not associated with an antidiuretic effect in hypophysectomized animals. C was 2.29±0.26 ml/min H2O before and 2.41±0.3 ml/min after vagotomy, and Uosm was 88±9.5 mOsm/kg before vagotomy and 78±8.6 mOsm/kg after vagotomy in the hypophysectomized animals. -
Hypernatremia Due to Urea-Induced Osmotic Diuresis: Physiology at The
Educational Forum Hypernatremia due to Urea-Induced Osmotic Diuresis: Physiology at the Bedside Sonali Vadi, Kenneth Yim1 Private Practitioner, Mumbai, Maharashtra, India, 1Director of Inpatient Hemodialysis‑Davita Dialysis, University of Maryland Midtown Campus, Maryland, USA Abstract Hypernatremia secondary to urea‑induced solute diuresis is due to the renal excretion of electrolyte‑free water. This concept is explained here step‑wise physiologically with the help of a clinical vignette. Keywords: Electrolyte‑free water clearance, hypernatremia, hypertonicity, osmotic diuresis, urea BACKGROUND Her initial laboratory data are presented in Table 1 and electrolyte trends during the hospital stay are summarized in Equation between solutes and water determines serum sodium Table 2. levels. Increased urinary solute load in the form of urea nitrogen leads to urea‑induced osmotic diuresis with increased Acute issues at hand free water loss and ensued hypernatremia. Diagnostic 1. What is the cause of her renal dysfunction? CLINICAL VIGNETTE 2. Why is she hypernatremic? A 70‑year‑old woman was found unconscious at home. As Treatment per her family members, she complained of abdominal pain 1. Should she be urgently dialyzed? and diarrhea for 1 week’s duration. Her baseline mental 2. How should her hypernatremia be managed? status was noted to be alert and oriented three days prior to presentation. Her medical history was significant for DISCUSSION hypertension and osteoarthritis. There was no prior history of renal dysfunction. She has been a heavy alcohol drinker. This complex pathological situation has been de‑coded Her medications included ibuprofen and cyclobenzaprine step‑wise in a question format, with answers to each in two for osteoarthritis; lisinopril and felodipine for hypertension; parts. -
The Use of Selected Urine Chemistries in the Diagnosis of Kidney Disorders
CJASN ePress. Published on January 9, 2019 as doi: 10.2215/CJN.10330818 The Use of Selected Urine Chemistries in the Diagnosis of Kidney Disorders Biff F. Palmer1 and Deborah Joy Clegg2 Abstract Urinary chemistries vary widely in both health and disease and are affected by diet, volume status, medications, and disease states. When properly examined, these tests provide important insight into the mechanism and therapy of 1Division of various clinical disorders that are first detected by abnormalities in plasma chemistries. These tests cannot be Nephrology, interpreted in isolation, but instead require knowledge of key clinical information, such as medications, physical Department of examination, and plasma chemistries, to include kidney function. When used appropriately and with knowledge of Medicine, University of Texas Southwestern limitations, urine chemistries can provide important insight into the pathophysiology and treatment of a wide Medical Center, variety of disorders. Dallas, Texas; and Clin J Am Soc Nephrol 14: ccc–ccc, 2019. doi: https://doi.org/10.2215/CJN.10330818 2Department of Internal Medicine, University of California, Los Introduction values ,15 mEq/L. On the other hand, volume Angeles School of Urine chemistries can provide valuable insight into a expansion suppresses effector mechanisms and stimu- Medicine, Los wide range of clinical conditions. These tests are often lates release of atrial natriuretic peptide, leading to a Angeles, California underutilized because of the difficulty many physi- reduction in sodium reabsorption, causing urinary so- Correspondence: cians find in their interpretation. Whereas a basic dium concentration to be high. Thus, the urine sodium fi Dr. Biff F. Palmer, metabolic pro le obtained from a blood sample has concentrationisanindirectmeasureofvolumestatusand Department of Internal well defined normal values, there are no such values reflects the integrity of the kidney to regulate that status.