원위부 신세뇨관성 산증에서 산-염기 운반체의 결손

김혜영,한진석,전은실,진호준,주권욱,나기영,정우경,오지은,김현리,이서진,이중건,김근호,엄재호,궁성수,김진,이정상 대한신장학회 2000 대한신장학회잡지 Vol.19 No.5

이뇨제의 저항성과 내성 기전

오윤규,나기영,김근호,김소영,한진석 대한신장학회 2001 대한신장학회잡지 Vol.20 No.5

Pseudohyponatremia : Does It Matter in Current Clinical Practice?

( Gheun Ho Kim ) 대한전해질학회 2006 Electrolytes & Blood Pressure Vol.4 No.2

Serum consists of water (93% of serum volume) and nonaqueous components, mainly lipids and proteins (7% of serum volume). Sodium is restricted to serum water. In states of hyperproteinemia or hyperlipidemia, there is an increased mass of the nonaqueous components of serum and a concomitant decrease in the proportion of serum composed of water. Thus, pseudohyponatremia results because the flame photometry method measures sodium concentration in whole plasma. A sodium-selective electrode gives the true, physiologically pertinent sodium concentration because it measures sodium activity in serum water. Whereas the serum sample is diluted in indirect potentiometry, the sample is not diluted in direct potentiometry. Because only direct reading gives an accurate concentration, we suspect that indirect potentiometry which many hospital laboratories are now using may mislead us to confusion in interpreting the serum sodium data. However, it seems that indirect potentiometry very rarely gives us discernibly low serum sodium levels in cases with hyperproteinemia and hyperlipidemia. As long as small margins of errors are kept in mind of clinicians when serum sodium is measured from the patients with hyperproteinemia or hyperlipidemia, the present methods for measuring sodium concentration in serum by indirect sodium-selective electrode potentiometry could be maintained in the clinical practice.

Pharmacologic Treatment of Chronic Hyperkalemia in Patients with Chronic Kidney Disease

Gheun-Ho Kim 전해질고혈압연구회 2019 Electrolytes & Blood Pressure Vol.17 No.1

Hyperkalemia is frequently complicated in patients with advanced chronic kidney disease(CKD) because kidney is the major route of potassium excretion. Urinary potassium excretion is reduced according to the decline in glomerular filtration rate, and the risk of hyperkalemia is increased in patients with high potassium intake, advanced age, diabetes mellitus, congestive heart failure, and medica- tions such as renin-angiotensin-aldosterone system(RAAS) blockades. On the other hand, the benefits of RAAS blockades and a high-potassium diet should be considered in CKD patients. To overcome these contradictory treatment stra- tegies, potassium binders have emerged as new options to enhance fecal pota- ssium excretion. In different regions of the world, four types of potassium binders are preferentially used. Whereas sodium polystyrene sulfonate(SPS) exchanges sodium for potassium, calcium polystyrene sulfonate(CPS) has the advantage of avoiding hypervolemia because it exchanges calcium for potassium. SPS was first introduced in the 1950s and used for a long time in western countries, and CPS is currently prescribed in Asia including South Korea. In contrast with the paucity of clinical studies using SPS or CPS, the recent ran- domized, controlled trials reported that two newer potassium binders, patiromer and sodium zirconium cyclosilicate(ZS-9), effectively and safely reduce serum potassium levels in CKD patients taking RAAS blockades. Our experiences showed that the long-term administration of a small dose of CPS was also effec- tive and safe in treatment of chronic hyperkalemia. Further comparative trials among patiromer, ZS-9, and CPS are required to provide guides to cost-effective management of hyperkalemia in CKD patients.

Treating lithium-induced nephrogenic diabetes insipidus with a COX-2 inhibitor improves polyuria via upregulation of AQP2 and NKCC2.

Kim, Gheun-Ho,Choi, Nak Won,Jung, Ju-Young,Song, Ji-Hyun,Lee, Chang Hwa,Kang, Chong Myung,Knepper, Mark A American Physiological Society 2008 American Journal of Physiology Vol.294 No.4

<P>Prostaglandin E(2) may antagonize vasopressin-stimulated salt absorption in the thick ascending limb and water absorption in the collecting duct. Blockade of prostaglandin E(2) synthesis by nonsteroidal anti-inflammatory drugs (NSAIDs) enhances urinary concentration, and these agents have antidiuretic effects in patients with nephrogenic diabetes insipidus (NDI) of different etiologies. Because renal prostaglandins are derived largely from cyclooxygenase-2 (COX-2), we hypothesized that treatment of NDI with a COX-2 inhibitor may relieve polyuria through increased expression of Na-K-2Cl cotransporter type 2 (NKCC2) in the thick ascending limb and aquaporin-2 (AQP2) in the collecting duct. To test this hypothesis, semiquantitative immunoblotting and immunohistochemistry were carried out from the kidneys of lithium-induced NDI rats with and without COX-2 inhibition. After male Sprague-Dawley rats were fed an LiCl-containing rat diet for 3 wk, the rats were randomly divided into control and experimental groups. The COX-2 inhibitor DFU (40 mg.kg(-1).day(-1)) was orally administered to the experimental rats for an additional week. Treatment with the COX-2 inhibitor significantly relieved polyuria and raised urine osmolality. Semiquantitative immunoblotting using whole-kidney homogenates revealed that COX-2 inhibition caused significant increases in the abundance of AQP2 and NKCC2. Immunohistochemistry for AQP2 and NKCC2 confirmed the effects of COX-2 inhibition in lithium-induced NDI rats. The upregulation of AQP2 and NKCC2 in response to the COX-2 inhibitor may underlie the therapeutic mechanisms by which NSAIDs enhance antidiuresis in patients with NDI.</P>

Renal Effects of Prostaglandins and Cyclooxygenase-2 Inhibitors

( Gheun Ho Kim ) 대한전해질학회 2008 Electrolytes & Blood Pressure Vol.6 No.1

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.

Hepcidin as a Biomarker of Cardiorenal Syndrome

Gheun-Ho Kim 대한의학회 2020 Journal of Korean medical science Vol.35 No.1

Anemia is frequently accompanied with advanced chronic kidney disease (CKD), and its prevalence was reported to be 45% among 2,198 non-dialysis CKD patients from stage 1 to 5 in Korea.1 Treatment of anemia is very important in CKD because anemia itself can cause high-output heart failure and lead to cardiovascular mortality. Thus, anemia may be the common denominator in progression of cardiorenal syndrome. The importance of managing cardiorenal syndrome is recently reemerging because CKD and heart failure are frequently associated and influence each other in a vicious cycle of comorbidity that increases the risk of mortality.

Review : Gaps between Global Guidelines and Local Practices in CKD-MBD

( Gheun Ho Kim ) 대한전해질학회 2014 Electrolytes & Blood Pressure Vol.12 No.2

The term ‘chronic kidney disease-mineral bone disorder’ (CKD-MBD) is a new term that, in contrast to the old term ‘renal osteodystrophy’, implies a systemic syndrome associated with cardiovascular morbidity and mortality. This new terminology is in line with previous studies that show elevated serum calcium, phosphorus, and parathyroid hormone (PTH) levels associated with increased cardiovascular and all-cause mortality. In order to improve outcomes in patients with CKD-MBD, many countries have developed clinical practice guidelines. Globally, the Kidney Disease Outcome Quality Initiative (KDOQI) and Kidney Disease: Improving Global Outcomes (KDIGO) guidelines are the most commonly used. However, whether these global guidelines can be successfully implemented on a local level needs to be studied. Differences in medical care and social factors between countries may limit the generalizability of global guidelines. Reports from the Korean registry and the Dialysis Outcomes and Practice Patterns Study (DOPPS) suggest that many dialysis patients are not within the target ranges recommended by the KDOQI and KDIGO guidelines for serum calcium, phosphorus, and PTH, suggesting gaps between global guidelines and local practices. Clinical studies with Korean CKD-MBD patients are necessary to compare Korean practices and outcomes to those suggested by global guidelines and to determine the target serum mineral levels associated with the best local outcomes.

Edematous Hyponatremia Treated with Tolvaptan in a Patient with Amyotrophic Lateral Sclerosis

( Gheun-ho Kim ) 대한전해질학회 2017 Electrolytes & Blood Pressure Vol.15 No.2

Amyotrophic lateral sclerosis (ALS) patients rarely present with either syn-drome of inappropriate antidiuretic hormone secretion or generalized edema. Tolvaptan is a selective vasopressin V2 receptor antagonist that produces effective aquaresis, and its use in ALS patients has not been previously reported. A 50-year-old male ALS patient was admitted be-cause of both generalized edema and dilutional hyponatremia. These manifestations were refractory to conventional diuretics and fluid therapy, but a very brisk diuresis was induced by tolvaptan administration. Edema and hyponatremia were also improved, and the patient was able to be discharged without tolvaptan. In this case report, we postulate how edema and dilutional hyponatremia developed in the patient, and discuss the mechanism of tolvaptan in treating hypervolemic hyponatremia. Further experience is necessary to evaluate the usefulness of tolvaptan in pa-tients with neurological disorders.

Reviews : Dialysis Unphysiology and Sodium Balance

( Gheun Ho Kim ) 대한전해질학회 2009 Electrolytes & Blood Pressure Vol.7 No.2

Dialysis unphysiology was first discussed by Carl Kjellstrand in 1975 for the possible negative effects of the unphysiology of intermittent dialysis treatment. Current hemodialysis practices are still unphysiologic because they cannot keep blood chemistries within normal limits, both before and after dialysis. In addition, the discontinuous nature of hemodialysis causes saw-tooth volume fluctuations, and the extracellular fluid volume expansion during the interdialytic period may lead to hypertension and adverse cardiovascular consequences. Sodium, which is accumulated over the interdialytic period, may be divided into two fractions. The one is the fraction of osmotically active sodium which is mainly confined to the extracellular space, and the other is that of water-free (osmotically inactive) sodium which diffuses into the intracellular space. Both contribute to the pathogenesis of hypertension because the former may act to expand extracellular fluid volume and the latter may cause vasoconstriction in the long run by increasing cytosolic concentration of calcium in the vascular smooth muscle cells. Even in intensive hemodialysis, it may take several weeks to months for water-free sodium storage in the vascular smooth muscle cells to be relieved. This may be an explanation for the lag phenomenon, i.e., the delay of blood pressure decrease after normalization of extracellular fluid volume shown in the Tassin experience. Modest restriction of dietary sodium intake, the dialytic session length long enough to maintain a high ultrafiltration volume, and the reasonably low dialysate sodium concentration are required to avoid unphysiology of positive sodium balance in current hemodialysis practice.