scholarly journals Intermittent hypoxia exacerbates increased blood pressure in rats with chronic kidney disease

2018 ◽  
Vol 315 (4) ◽  
pp. F927-F941 ◽  
Author(s):  
Jennifer L. Riggs ◽  
Carolyn E. Pace ◽  
Heather H. Ward ◽  
Laura V. Gonzalez Bosc ◽  
Lynnette Rios ◽  
...  

Kidney injury and sleep apnea (SA) are independent risk factors for hypertension. Exposing rats to intermittent hypoxia (IH) to simulate SA increases blood pressure whereas adenine feeding causes persistent kidney damage to model chronic kidney disease (CKD). We hypothesized that exposing CKD rats to IH would exacerbate the development of hypertension and renal failure. Male Sprague-Dawley rats were fed a 0.2% adenine diet or control diet (Control) until blood urea nitrogen was >120 mg/dl in adenine-fed rats (14 ± 4 days, mean ± SE). After 2 wk of recovery on normal chow, rats were exposed to IH (20 exposures/h of 5% O2-5% CO2 7 h/day) or control conditions (Air) for 6 wk. Mean arterial pressure (MAP) was monitored with telemeters, and plasma and urine samples were collected weekly to calculate creatinine clearance as an index of glomerular filtration rate (GFR). Prior to IH, adenine-fed rats had higher blood pressure than rats on control diet. IH treatment increased MAP in both groups, and after 6 wk, MAP levels in the CKD/IH rats were greater than those in the CKD/Air and Control/IH rats. MAP levels in the Control/Air rats were lower than those in the other three groups. Kidney histology revealed crystalline deposits, tubule dilation, and interstitial fibrosis in both CKD groups. IH caused no additional kidney damage. Plasma creatinine was similarly increased in both CKD groups throughout whereas IH alone increased plasma creatinine. IH increases blood pressure further in CKD rats without augmenting declines in GFR but appears to impair GFR in healthy rats. We speculate that treating SA might decrease hypertension development in CKD patients and protect renal function in SA patients.

2012 ◽  
Vol 50 (1) ◽  
pp. 147-155 ◽  
Author(s):  
S. Chakrabarti ◽  
H. M. Syme ◽  
C. A. Brown ◽  
J. Elliott

Chronic kidney disease is common in geriatric cats, but most cases have nonspecific renal lesions, and few studies have correlated these lesions with clinicopathological markers of renal dysfunction. The aim of this study was to identify the lesions best correlated with renal function and likely mediators of disease progression in cats with chronic kidney disease. Cats were recruited through 2 first-opinion practices between 1992 and 2010. When postmortem examinations were authorized, renal tissues were preserved in formalin. Sections were evaluated by a pathologist masked to all clinicopathological data. They were scored semiquantitatively for the severity of glomerulosclerosis, interstitial inflammation, and fibrosis. Glomerular volume was measured using image analysis; the percentage of glomeruli that were obsolescent was recorded. Sections were assessed for hyperplastic arteriolosclerosis and tubular mineralization. Kidneys from 80 cats with plasma biochemical data from the last 2 months of life were included in the study. Multivariable linear regression ( P < .05) was used to assess the association of lesions with clinicopathological data obtained close to death. Interstitial fibrosis was the lesion best correlated with the severity of azotemia, hyperphosphatemia, and anemia. Proteinuria was associated with interstitial fibrosis and glomerular hypertrophy, whereas higher time-averaged systolic blood pressure was associated with glomerulosclerosis and hyperplastic arteriolosclerosis.


2013 ◽  
Vol 304 (7) ◽  
pp. C591-C603 ◽  
Author(s):  
Gabriela Campanholle ◽  
Giovanni Ligresti ◽  
Sina A. Gharib ◽  
Jeremy S. Duffield

Chronic kidney disease, defined as loss of kidney function for more than three months, is characterized pathologically by glomerulosclerosis, interstitial fibrosis, tubular atrophy, peritubular capillary rarefaction, and inflammation. Recent studies have identified a previously poorly appreciated, yet extensive population of mesenchymal cells, called either pericytes when attached to peritubular capillaries or resident fibroblasts when embedded in matrix, as the progenitors of scar-forming cells known as myofibroblasts. In response to sustained kidney injury, pericytes detach from the vasculature and differentiate into myofibroblasts, a process not only causing fibrosis, but also directly contributing to capillary rarefaction and inflammation. The interrelationship of these three detrimental processes makes myofibroblasts and their pericyte progenitors an attractive target in chronic kidney disease. In this review, we describe current understanding of the mechanisms of pericyte-to-myofibroblast differentiation during chronic kidney disease, draw parallels with disease processes in the glomerulus, and highlight promising new therapeutic strategies that target pericytes or myofibroblasts. In addition, we describe the critical paracrine roles of epithelial, endothelial, and innate immune cells in the fibrogenic process.


Author(s):  
Natalie Ebert ◽  
Elke Schaeffner

Both acute and chronic states of kidney disease have considerable healthcare impact as they can produce enormous disease burden and costs. To classify chronic kidney disease into the CKD staging system, glomerular filtration rate as an index of kidney function, as well as albuminuria as a marker of kidney damage have to be assessed as correctly as possible. Misclassification is a serious concern due to the difficulties in precise GFR assessment and correct interpretation of results. Differentiating between pure senescence and true disease among older adults can be a delicate issue. To find the right renal replacement option for individuals that progress to end-stage renal disease can be challenging, and some older patients may even benefit from conservative care without dialysis. To prevent acute kidney injury as a frequent and potentially life-threatening complication, clinicians need to develop an understanding of the common vulnerability to kidney damage among older adults.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Patricia Rivera ◽  
Catalina Miranda ◽  
Nicole Roldán ◽  
Aaron Guerrero ◽  
Javier Olave ◽  
...  

AbstractObesity has been firmly established as a major risk factor for common disease states including hypertension, type 2 diabetes mellitus, and chronic kidney disease. Increased body mass index (BMI) contributes to the activation of both the systemic and intra-tubular renin angiotensin systems (RAS), which are in turn associated with increased blood pressure (BP) and kidney damage. In this cross-sectional study, 43 subjects of normal or increased body weight were examined in order to determine the correlation of BMI or body fat mass (BFM) with blood pressure, fasting blood glucose (FBG), and urinary kidney injury markers such as interleukin-18 (IL-18), connective tissue growth factor (CTGF), neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 (KIM-1). Our results showed that: (1) subjects with increased body weight showed significantly higher BP, BFM, total body water and metabolic age; (2) BMI was positively correlated to both systolic (R2 = 0.1384, P = 0.01) and diastolic BP (R2 = 0.2437, P = 0.0008); (3) BFM was positively correlated to DBP (R2 = 0.1232, P = 0.02) and partially correlated to urine protein (R2 = 0.047, P = 0.12) and FBG (R2 = 0.07, P = 0.06); (4) overweight young adults had higher urinary mRNA levels of renin, angiotensinogen, IL-18 and CTGF. These suggest that BMI directly affects BP, kidney injury markers, and the activation of the intra-tubular RAS even in normotensive young adults. Given that BMI measurements and urine analyses are non-invasive, our findings may pave the way to developing a new and simple method of screening for the risk of chronic kidney disease in adults.


2014 ◽  
Vol 307 (11) ◽  
pp. F1169-F1178 ◽  
Author(s):  
Vishal Diwan ◽  
David Small ◽  
Kate Kauter ◽  
Glenda C. Gobe ◽  
Lindsay Brown

Gender contributes to differences in incidence and progression of chronic kidney disease (CKD) and associated cardiovascular disease. To induce kidney damage in male and female Wistar rats ( n = 12/group), a 0.25% adenine diet for 16 wk was used. Kidney function (blood urea nitrogen, plasma creatinine, proteinuria) and structure (glomerular damage, tubulointerstitial atrophy, fibrosis, inflammation); cardiovascular function (blood pressure, ventricular stiffness, vascular responses, echocardiography) and structure (cardiac fibrosis); plasma testosterone and estrogen concentrations; and protein expression for oxidative stress [heme oxygenase-1, inflammation (TNF-α), fibrosis (transforming growth factor-β), ERK1/2, and estrogen receptor-α (ER-α)] were compared in males and females. Adenine-fed females had less decline in kidney function than adenine-fed males, although kidney atrophy, inflammation, and fibrosis were similar. Plasma estrogen concentrations increased and plasma testosterone concentrations decreased in adenine-fed males, with smaller changes in females. CKD-associated molecular changes in kidneys were more pronounced in males than females except for expression of ER-α in the kidney, which was completely suppressed in adenine-fed males but unchanged in adenine-fed females. Both genders showed increased blood pressure, ventricular stiffness, and cardiac fibrosis with the adenine diet. Cardiovascular changes with adenine were similar in males and females, except males developed concentric, and females eccentric cardiac hypertrophy. In hearts from adenine-fed male and female rats, expression of ER-α and activation of the ERK1/2 pathway were increased, in part explaining changes in cardiac hypertrophy. In summary, adenine-induced kidney damage may be increased in males due to the suppression of ER-α.


2022 ◽  
Vol 23 (2) ◽  
pp. 747
Author(s):  
Meihui Wang ◽  
Zixu Wang ◽  
Yaoxing Chen ◽  
Yulan Dong

The rapid growth of obesity worldwide has made it a major health problem, while the dramatic increase in the prevalence of obesity has had a significant impact on the magnitude of chronic kidney disease (CKD), especially in developing countries. A vast amount of researchers have reported a strong relationship between obesity and chronic kidney disease, and obesity can serve as an independent risk factor for kidney disease. The histological changes of kidneys in obesity-induced renal injury include glomerular or tubular hypertrophy, focal segmental glomerulosclerosis or bulbous sclerosis. Furthermore, inflammation, renal hemodynamic changes, insulin resistance and lipid metabolism disorders are all involved in the development and progression of obesity-induced nephropathy. However, there is no targeted treatment for obesity-related kidney disease. In this review, RAS inhibitors, SGLT2 inhibitors and melatonin would be presented to treat obesity-induced kidney injury. Furthermore, we concluded that melatonin can protect the kidney damage caused by obesity by inhibiting inflammation and oxidative stress, revealing its therapeutic potential.


2016 ◽  
Vol 310 (6) ◽  
pp. F560-F568 ◽  
Author(s):  
Cierra N. Sharp ◽  
Mark A. Doll ◽  
Tess V. Dupre ◽  
Parag P. Shah ◽  
Marimuthu Subathra ◽  
...  

Cisplatin, a chemotherapeutic used for the treatment of solid cancers, has nephrotoxic side effects leading to acute kidney injury (AKI). Cisplatin cannot be given to patients that have comorbidities that predispose them to an increased risk for AKI. Even without these comorbidities, 30% of patients administered cisplatin will develop kidney injury, requiring the oncologist to withhold or reduce the next dose, leading to a less effective therapeutic regimen. Although recovery can occur after one episode of cisplatin-induced AKI, longitudinal studies have indicated that multiple episodes of AKI lead to the development of chronic kidney disease, an irreversible disease with no current treatment. The standard mouse model of cisplatin-induced AKI consists of one high dose of cisplatin (>20 mg/kg) that is lethal to the animal 3 days later. This model does not accurately reflect the dosing regimen patients receive nor does it allow for the long-term study of kidney function and biology. We have developed a repeated dosing model whereby cisplatin is given once a week for 4 wk. Comparison of the repeated dosing model with the standard dosing model demonstrated that inflammatory cytokines and chemokines were induced in the repeated dosing model, but levels of cell death were lower in the repeated dosing model. The repeated dosing model had increased levels of fibrotic markers (fibronectin, transforming growth factor-β, and α-smooth muscle actin) and interstitial fibrosis. These data indicate that the repeated dosing model can be used to study the AKI to chronic kidney disease progression as well as the mechanisms of this progression.


2018 ◽  
Vol 169 (9) ◽  
pp. 610 ◽  
Author(s):  
William R. Zhang ◽  
Timothy E. Craven ◽  
Rakesh Malhotra ◽  
Alfred K. Cheung ◽  
Michel Chonchol ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Nima Abbasian ◽  
Maryam Ghaderi-Najafabadi ◽  
Emma Watson ◽  
Jeremy Brown ◽  
Li Yu si ◽  
...  

Abstract Background Taurine depletion occurs in patients with end-stage chronic kidney disease (CKD). In contrast, in the absence of CKD, plasma taurine is reported to increase following dietary L-glutamine supplementation. This study tested the hypothesis that taurine biosynthesis decreases in a rat CKD model, but is rectified by L-glutamine supplementation. Methods CKD was induced by partial nephrectomy in male Sprague-Dawley rats, followed 2 weeks later by 2 weeks of 12% w/w L-glutamine supplemented diet (designated NxT) or control diet (NxC). Sham-operated control rats (S) received control diet. Results Taurine concentration in plasma, liver and skeletal muscle was not depleted, but steady-state urinary taurine excretion (a measure of whole-body taurine biosynthesis) was strongly suppressed (28.3 ± 8.7 in NxC rats versus 78.5 ± 7.6 μmol/24 h in S, P < 0.05), accompanied by reduced taurine clearance (NxC 0.14 ± 0.05 versus 0.70 ± 0.11 ml/min/Kg body weight in S, P < 0.05). Hepatic expression of mRNAs encoding key enzymes of taurine biosynthesis (cysteine sulphinic acid decarboxylase (CSAD) and cysteine dioxygenase (CDO)) showed no statistically significant response to CKD (mean relative expression of CSAD and CDO in NxC versus S was 0.91 ± 0.18 and 0.87 ± 0.14 respectively). Expression of CDO protein was also unaffected. However, CSAD protein decreased strongly in NxC livers (45.0 ± 16.8% of that in S livers, P < 0.005). L-glutamine supplementation failed to rectify taurine biosynthesis or CSAD protein expression, but worsened CKD (proteinuria in NxT 12.5 ± 1.2 versus 6.7 ± 1.5 mg/24 h in NxC, P < 0.05). Conclusion In CKD, hepatic CSAD is depleted and taurine biosynthesis impaired. This is important in view of taurine’s reported protective effect against cardio-vascular disease - the leading cause of death in human CKD.


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