OBJECTIVE: To analyze association between urodynamic study (UDS) parameters and renal function in spinal cord injured (SCI) patients with neurogenic detrusor overactivity. METHODS: Patients with a suprasacral SCI, who underwent UDS and radioisotope renogram at least twice between January 1, 2006 and January 31, 2013, were included. UDS (cystometric capacity, reflex volume, compliance, and maximal detrusor pressure) and radioisotope renogram (total effective renal plasma flow [ERPF] of both kidneys) data were collected. The following were conducted to reanalyze any association between reflex volume and ERPF: initial and follow-up results of consecutive evaluations were compared; a mixed-model regression analysis to account for clustered data was conducted to evaluate the association between UDS parameters and ERPF; and finally, a mixed-model analysis type 3 test with data pairs, of which the first evaluation showed involuntary detrusor contraction. RESULTS: A total of 150 patients underwent 390 evaluations which were arranged into 240 pairs of consecutive evaluations, of which 171 had first evaluations with observed involuntary detrusor contraction. The following results were obtained: cystometric capacity was significantly larger and maximal detrusor pressure was significantly lower on follow-up; on univariate analysis, reflex volume and maximal detrusor pressure were significant, and multivariate analysis using these two parameters showed that maximal detrusor pressure is significantly associated with total ERPF; and no significant differences were observed. CONCLUSION: Maximal detrusor pressure should be closely monitored in the urologic management of neurogenic detrusor overactivity in SCI patients. The results also may serve as a reference for regular UDS follow-up.
Compliance ; Follow-Up Studies ; Humans ; Multivariate Analysis ; Reflex ; Renal Plasma Flow ; Renal Plasma Flow, Effective ; Spinal Cord ; Spinal Cord Injuries* ; Urinary Bladder, Neurogenic ; Urodynamics*

Prostaglandins (PGs) with best-defined renal functions are PGE2 and prostacyclin (PGI2). These vasodilatory PGs increase renal blood flow and glomerular filtration rate under conditions associated with decreased actual or effective circulating volume, resulting in greater tubular flow and secretion of potassium. Under conditions of decreased renal perfusion, the production of renal PGs serves as an important compensatory mechanism. PGI2 (and possibly PGE2) increases potassium secretion mainly by stimulating secretion of renin and activating the renin-angiotensin system, which leads to increased secretion of aldosterone. In addition, PGE2 is involved in the regulation of sodium and water reabsorption and acts as a counterregulatory factor under conditions of increased sodium reabsorption. PGE2 decreases sodium reabsorption at the thick ascending limb of the loop of Henle probably via inhibition of the Na+-K+-2Cl-cotransporter type 2 (NKCC2). Cyclooxygenase inhibitors may enhance urinary concentrating ability in part through effects to upregulate NKCC2 in the thick ascending limb of Henle's loop and aquaporin-2 in the collecting duct. Thus, they may be useful to treat Bartter's syndrome and nephrogenic diabetes insipidus.
Aldosterone ; Aquaporin 2 ; Bartter Syndrome ; Cyclooxygenase 2 ; Cyclooxygenase 2 Inhibitors ; Cyclooxygenase Inhibitors ; Diabetes Insipidus, Nephrogenic ; Dinoprostone ; Epoprostenol ; Extremities ; Glomerular Filtration Rate ; Kidney ; Kidney Concentrating Ability ; Loop of Henle ; Perfusion ; Potassium ; Prostaglandins ; Renal Circulation ; Renin ; Renin-Angiotensin System ; Sodium ; Water

OBJECTIVE: The purposes of this study were to determine the renal function by radioisotope renography and to compare the findings of radioisotope renography in the spinal cord injured patients to the clinical presentations and findings of other conventional urologic examinations. METHOD: Intravenous pyelogram(IVP), voiding cystourethrogram(VCUG) and urodynamic study were performed in twenty-five spinal cord injured patients along with serum BUN/Creatinine levels and 24 hour creatinine clearance tests. Technetium-99 m mercaptoacetyltriglycine was used for the radioisotope renography. RESULTS: One abnormal radioisotope renography finding was noted among 22 normal findings by IVP and VCUG studies, while no abnormal finding by IVP and VCUG studies was noted among the subjects with a normal radioisotope renography. Effective renal plasma flow(ERPF) was significantly lower in patients with lower creatinine clearance. ERPF, cortical retention and creatinine clearance values for hyperreflexic bladders were significantly different from areflexic bladders. ERPF was significantly higher in a clean intermittent catheterization group than in a percussion and Cred method group for the hyperreflexic bladders. CONCLUSION: The study proves that the radioisotope renography is a sensitive and valuable study to evaluate the renal dysfunction in the spinal cord injured patients.
Creatinine ; Humans ; Intermittent Urethral Catheterization ; Percussion ; Plasma ; Radioisotope Renography* ; Renal Plasma Flow, Effective ; Spinal Cord Injuries* ; Spinal Cord* ; Urinary Bladder ; Urodynamics

Arginine vasopressin(AVP) released from the posterior pituitary gland is well known to cause an increase in blood pressure, antidiuresis, natriuresis and inhibition of renin secretion. However, the mechanism involved in AVP-induced natriuresis is still unknown. To investigate the mechanism of AVP- induced natriuresis, different doses of AVP were infused into the left renal artery for 10 min and renal function and data were obtained in unanesthetized rabbits. Infusion of different doses of AVP (0.3pg/kg/min-10,000pg/kg/min) caused marked decreases in urine volume, renal blood flow, glomerular filtration rate and free water clearance without changes in blood pressure. Changes in renal function by AVP were not dose-dependent but it took more time for the renal function to recover with increasing doses. Infusion of large doses of AVP(3,000, 10,000pg/kg/min) caused increases in sodium excretion in both kidneys without changes in blood pressure. Infusion of AVP caused a decrease in renin secretion rate. In indomethacin-treated rabbits, changes in urine volume and renal hemodynamics by AVP were markedly accentuated whereas natriuretic effects were attenuated. However, a marked natriuresis caused by AVP in control right kidney still persistently existed. These results suggest that the AVP-induced natriuresis may occur in two-different ways: one is indirect hormonal including prostaglandins and the other is tubular.
Arginine Vasopressin* ; Arginine* ; Blood Pressure ; Glomerular Filtration Rate ; Hemodynamics ; Kidney ; Natriuresis ; Natriuretic Agents ; Pituitary Gland, Posterior ; Prostaglandins ; Rabbits* ; Renal Artery ; Renal Circulation ; Renin* ; Sodium ; Water

This study was undertaken to determine whether verapamil protects renal function in rabbits with ischemic acute renal failure. Renal ischemia was induced by clamping bilateral renal arteries for 60 min. One group received intravenously an infusion of verapamil (lmg/kg) for 30 min prior to initiation of renal artery clamping and the other group received equal volume of saline. Renal blood flow was measured with flowmeter before (basal) and 24 hr after ischemia. Serum creatinine level increased 24 hr after ischemia and remained high to 72 hr. When verapamil was pretreated, the level 48 and 72 hr after ischemia was significantly decreased compared with saline insusion. Urine flow was markedly decreased 24 hr after ischemia and remained depressed to 72 hr, but it was significantly increased 72 hr after ischemia in verapa- mil-pretreatment animals as compared with the saline-infusion animals. GFR were markedly reduced 24 hr after ischemia and remained depressed to 72 hr, which was significantly prevented by verapamil pretreatment. Ischemia caused a significant increase in FEVa and a reduction in Uosm, and TcH2O, indicating impairment in urine concentrating ability of tubules, and the impairment was significantly attenuated by verapamil. The uptake of p-aminohippurate in cortical slices was depressed by ischemia, which was significantly prevented by verapamil pretreatment. In salineinfusion animals, renal blood flow was not significantly different between the basal value and that after 24 hr of reflow. Renal blood flow was not significantly altered by verapamil pretreatment. Anoxia/reoxygenation injury in the control renal slices was not significantly prevented by Ca channel blockers. These results suggest that verapamil exerts a protective effect in ichemic acute renal failure, and the beneficial effects may be attributed to effects other than vasodilation. These data also indicate that a reduction in GFR following ischemia does not result from change in renal blood flow.
Acute Kidney Injury* ; Animals ; Constriction ; Creatinine ; Flowmeters ; Ischemia ; Kidney Concentrating Ability ; p-Aminohippuric Acid ; Rabbits* ; Renal Artery ; Renal Circulation ; Vasodilation ; Verapamil*

OBJECTIVE: To evaluate the renal function by investigating the relationship among serum cystatin C, serum creatinine, creatinine clearance and the average of bilateral ERPF (effective renal plasma flow) ratio of the MAG3 renal scan for the spinal cord injured patients. METHOD: Seventy-one spinal cord injured patients who admitted to our department were evaluated from January 2004 to October 2004. Blood samples and 24-hour urine of all the subjects were collected for measuring serum cystatin C, serum creatinine and creatinine clearance. MAG3 renal scan was done for 47 subjects. Regression analysis and Pearson's correlation methods were utilized for statistical analysis. RESULTS: There was significant correlation between 1/cystatin C and creatinine clearance (p<0.001) and the correlation coefficient between 1/cystatin C vs. creatinine clearance (R= 0.552) was bigger than that between 1/creatinine and creatinine clearance (R=0.329). The reciprocal of cystatin C was positively correlated with the average of bilateral ERPF ratio of MAG3 renal scan (p=0.01), while there was no significant correlation between 1/creatinine and the average of bilateral ERPF ratio. CONCLUSION: Measurement of serum cystatin C is a useful and convenient method for the evaluation of renal function in spinal cord injured patients.
Creatinine ; Cystatin C* ; Humans ; Plasma ; Renal Plasma Flow, Effective ; Spinal Cord Injuries ; Spinal Cord*

In an attempt to obtain evidence in the mechanism of stone formation, the effectiveness of Amiloride. a K-sparing diuretic known to act on the distal nephron. on the kidney with oxamide-induced urolithiasis was investigated. Futhermore. the influence of stone formation on the distribution of intrarenal blood flow and the effect of Amiloride on them were also studied. Most prominent derangements of renal function observed during stone formation were decreases of both C(PAH) and C(cr) indicating the curtailment in renal hemodynamics. The oxamide-treated kidney also responded to Amiloride with typical natriuresis and antikaluresis. in the same fashion with normal kidneys. The experiments in which the intrarenal blood flow distribution was measured by PAH-extraction technique raveled that mainly the cortical blood flow was curtailed, whereas non-cortical blood flow (medullary flow) did not change during oxamide-stone formation. Amiloride did not influence the intrarenal b100d flow distribution both in normal and oxamide kidneys. These observations suggest that oxamide-stone formation was initiated not by tubular necrosis produced by the toxic action of oxalate on the tubules, but rather by mechanical obstruction of the tubules.
Amiloride* ; Hemodynamics ; Kidney* ; Natriuresis ; Necrosis ; Nephrons ; Renal Circulation ; Urolithiasis

Adrenomedullin (AM) is a multi-functional peptide discovered in human pheochromocytoma. Initially, it was suggested that AM was synthesized only by tumor cells, however, subsequent studies revealed that it was produced also by normal adrenal medulla as well as by many other tissues. Now it is well established that AM functions as a circulating hormone and local paracrine mediator with multiple biological activities. AM stimulated cAMP production in human platelets and exerted potent and long-lasting hypotensive activity in the rat. AM is a physiologically relevant regulator in fluid and electrolyte homeostasis; inhibition both water and salt intake, increase renal blood flow, and cause diuresis and natriuresis. The up-regulation of cardiac AM system in hypertension may be a protective mechanism decreasing myocardial overload due to vasodilatory and natriuretic properties of AM, as well as limiting further myocardial hypertrophy and remodeling. AM may protect the kidney against ischemia-reperfusion injury. AM is also suggested as antiapoptotic, anti-inflammatory and angiogenic factor. In this review, I offer a review of our current knowledge on AM and give the putative role of AM in water-electrolyte balance, hypertension and kidney disease.
Adrenal Medulla ; Adrenomedullin* ; Angiogenesis Inducing Agents ; Animals ; Diuresis ; Homeostasis ; Humans ; Hypertension ; Hypertrophy ; Kidney Diseases ; Kidney* ; Natriuresis ; Pheochromocytoma ; Rats ; Renal Circulation ; Reperfusion Injury ; Up-Regulation ; Water-Electrolyte Balance

The renal function is under regulatory influence of central nervous system, in which various neurotransmitter and neuromodulator systems take part, and it has been known that kallikrein-kininogen- kinin system exists also in the brain, but its physiological role remains to be explored. This study was, therefore, undertaken to delineate the possible role of central kinin system in the regulation of renal function. Kallikrein given into a lateral ventricle(icv) of rabbit brain in doses ranging from 3 to 30 microgram/kg icv elicited increases in Na excretion and the fraction of filtered sodium excreted(FENa), as well as in urine flow rate. K excretion, however, did not parallel the Na excretion, but tended to decrease when the natriuresis reached its peak. Renal blood flow and glomerular filtration did not significantly change. Neither did free water reabsorption significantly change, but tended to decrease. The systemic blood pressure slightly increased. When 30 microgram/kg kallikrein was given intravenously, all the parameters of renal function and systemic blood pressure did not show any increase but decrease, primarily by decreased renal hemodynamics, resulting from transient hypotension. In experiments in which the plasma ANP was measured, the ANP level markedly increased, reaching more than 5 times the control value 25min after 30 microgram/kg icv, and lasting until the end of the experiment at 80min. The renal nerve activity increased with kallikrein, 30 microgram/kg icv, peaking at 1 min but it remained slightly increased until about 40 min, and then slightly declined. This indicates that the increased renal nerve activity may have antagonized or ameliorated the natriuretic effect of icv kallikrein. Lys-bradykinin(kallidin), a cleavage product from kallidinogen by kallikrein, when given icv in doses of 0.3 to 30 microgram/kg also produced increased Na excretion and diuresis. When CHA, a kallikrein inhibitor, was given icv in doses of 3-30 microgram/kg, elicited antidiuresis and antinatriuresis. However, pretreatment with CHA tended slightly to suppress the kallikrein effect. These results indicate that the central kallikrein- kinin system is involved in the central regulation of renal function, the activation of the system in the CNS resulting in increased natriuresis and diuresis, which are related to increased plasma ANP level, with the possible antagonistic effects of increased renal nerve activity.
Atrial Natriuretic Factor ; Blood Pressure ; Brain ; Central Nervous System ; Diuresis ; Filtration ; Hemodynamics ; Hypotension ; Kallidin* ; Kallikreins* ; Natriuresis ; Natriuretic Agents ; Neurotransmitter Agents ; Plasma ; Renal Circulation ; Sodium ; Water

PURPOSE: Low-dose dopamine (0.5-3 microgram/kg/min) increases renal blood flow, glomerular filtration rate and natriuresis and has protective and therapeutic effects on oliguric renal failures. Asphyxia is the most common cause of acute renal failure in neonates. But the protective effects of dopamine have never been reported in asphyxiated neonates. So we reported the effects of low-dose dopamine on the renal function of asphyxiated neonates. METHODS: Twenty-seven asphyxiated neonates who were admitted to the neonatal intensive care unit of Ewha Womans University hospital, from September, 1995 to June, 1997, were randomized to dopamine group (N=14, dopamine 0.5-3 microgram/kg/min) and control group (N=13). Serum creatinine (Pcr) and Na (PNa), urine creatinine (Ucr) and Na (UNa), urine output, creatinine clearance rate (Ccr), fractional excretion of Na (FENa) of two groups were compared on postnatal day 1, 3, 5. Incidences of acute renal failure and neonatal complications were also checked. RESULTS: The postnatal changes of Pcr (mg/dL), Ccr (mL/min/1.73m2) and FENa (%), on lst, 3rd & 5th days were not significnatly diffrent between dopamine group and control group. The postnatal changes of UNa (mmol/day) and urine output (ml/kg/hr) in dopamine group on 1st, 3rd & 5th days were significantly higher than those of control group (P<0.05). The incidence of acute renal failure, intraventricular hemorrhage, bronchopulmonary dysplasia, patient ductus arteriosus, sepsis and necrotizing enterocolitis were not significantly different between two groups. CONCLUSION: Low-dose dopamine, which was prophylactically given after birth in asphyxiated neonates, showed natriuretic and diuretic effects without significant increase of glomerular function.
Acute Kidney Injury ; Asphyxia ; Bronchopulmonary Dysplasia ; Creatinine ; Diuretics ; Dopamine* ; Ductus Arteriosus ; Enterocolitis, Necrotizing ; Female ; Glomerular Filtration Rate ; Hemorrhage ; Humans ; Incidence ; Infant, Newborn* ; Intensive Care, Neonatal ; Natriuresis ; Parturition ; Polymerase Chain Reaction ; Renal Circulation ; Renal Insufficiency ; Sepsis