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- Dolinina, Julia, et al.
(författare)
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Clemizole and La3+ salts ameliorate angiotensin II-induced glomerular hyperpermeability in vivo
- 2021
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Ingår i: Physiological Reports. - : Wiley. - 2051-817X. ; 9:10
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Tidskriftsartikel (refereegranskat)abstract
- Angiotensin II (Ang II) induces marked, dynamic increases in the permeability of the glomerular filtration barrier (GFB) in rats. After binding to its receptor, Ang II elicits Ca2+ influx into cells, mediated by TRPC5 and TRPC6 (transient receptor potential canonical type 5 and 6). Clemizole and La3+ salts have been shown to block TRPC channels in vitro, and we therefore tested their potential effect on Ang II-induced glomerular hyperpermeability. Anesthetized male Sprague-Dawley rats were infused with Ang II (80 ng kg–1min–1) alone, or together with clemizole or low-dose La3+ (activates TRPC5, blocks TRPC6) or high-dose La3+ (blocks both TRPC5 and TRPC6). Plasma and urine samples were taken during baseline and at 5 min after the start of the infusions and analyzed by high-performance size-exclusion chromatography for determination of glomerular sieving coefficients for Ficoll 10–80 Å (1–8 nm). Ang II infusion evoked glomerular hyperpermeability to large Ficolls (50–80 Å), which was ameliorated by clemizole, having no significant effect on glomerular filtration rate (GFR) or Ang II-mediated increase in mean arterial pressure (ΔMAP). In contrast, high- and low-dose La3+ significantly lowered ΔMAP and reduced Ang II-induced hyperpermeability. Combined, clemizole and low-dose La3+ were less effective at ameliorating Ang II-induced glomerular hyperpermeability than low-dose La3+ alone. In conclusion, our data show that both clemizole and La3+ are effective against Ang II-induced glomerular hyperpermeability, with differential effects on blood pressure. Further research using more specific blockers of TRPC5 and TRPC6 should be performed to reveal the underlying mechanisms.
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| 2. |
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| 3. |
- Dolinina, Julia, et al.
(författare)
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Glomerular hyperpermeability after acute unilateral ureteral obstruction : Effects of Tempol, NOS, RhoA, and Rac-1 inhibition
- 2018
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Ingår i: American Journal of Physiology - Renal Physiology. - : American Physiological Society. - 1522-1466 .- 1931-857X. ; 315:3, s. 445-453
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that proteinuria following urinary tract obstruction is mainly of a tubular nature. However, it is unknown whether there are also changes in glomerular permeability. In this study, we compared glomerular sieving coefficients (θ) of polydisperse fluorescein isothiocyanate (FITC)-Ficoll 70/400 following a 120-or 180-min unilateral ureteral obstruction (UUO) in anesthetized Sprague-Dawley rats. Samples were collected from the obstructed kidney at 5, 15, and 30 min postrelease and analyzed by means of high-pressure size-exclusion chromatography. After 120-min UUO, mean θ for Ficoll70Å was increased (P < 0.01) from 2.2 ± 0.5 × 10−5 (baseline) to 10.6 ± 10 × 10−5 15 min postrelease (highest value). After 180-min UUO, mean θ for Ficoll70Å was further increased (P < 0.001) from 1.4 ± 0.5 × 10−5 (baseline) to 40 ± 10 × 10−5 at 5 min postrelease (highest value). Administration of a reactive oxygen species (ROS) scavenger (Tempol; 1 mg·kg−1·min−1) partly abrogated the permeability effects following 120-min UUO but not after 180 min. Moreover, administration of the RhoA kinase inhibitor Y-27632, the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester, or Rac-1 inhibition did not ameliorate glomerular hyperpermeability following 180-min UUO. We show, for the first time, that acute UUO results in marked elevations in glomerular permeability. In addition, our data suggest a time-dependent pathophysiology of UUO-induced hyperpermeability, where reactive oxygen species generation may play an important role in the early stages.
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| 4. |
- Dolinina, Julia, et al.
(författare)
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Nitric oxide synthase inhibition causes acute increases in glomerular permeability in vivo, dependent upon reactive oxygen species
- 2016
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Ingår i: American Journal of Physiology: Renal, Fluid and Electrolyte Physiology. - : American Physiological Society. - 0363-6127. ; 311:5, s. 984-990
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing evidence that the permeability of the glomerular filtration barrier (GFB) is partly regulated by a balance between the bioavailability of nitric oxide (NO) and that of reactive oxygen species (ROS). It has been postulated that normal or moderately elevated NO levels protect the GFB from permeability increases, whereas ROS, through reducing the bioavailability of NO, have the opposite effect. We tested the tentative antagonism between NO and ROS on glomerular permeability in anaesthetized Wistar rats, in which the left ureter was cannulated for urine collection while simultaneously blood access was achieved. Rats were systemically infused with eitherL-NAME orL-NAME together with the superoxide scavenger Tempol, or together withL-arginine or the NO-donor DEA-NONOate, or the cGMP agonist 8-bromo-cGMP. To measure glomerular sieving coefficients (theta, θ) to Ficoll, rats were infused with FITC-Ficoll 70/400 (mol/radius 10-80 Å). Plasma and urine samples were analyzed by high-performance size-exclusion chromatography (HPSEC) for determination of θ for Ficoll repeatedly during up to 2 h.L-NAME increased θ for Ficoll70Å from 2.27 ± 1.30 ˟ 10-5 to 8.46 ± 2.06 ˟ 10-5 (n = 6, P < 0.001) in 15 min. Tempol abrogated these increases in glomerular permeability and an inhibition was also observed withL-arginine and with 8-bromo-cGMP. In conclusion, acute NO synthase inhibition in vivo byL-NAME caused rapid increases in glomerular permeability, which could be reversed by either an ROS antagonist or by activating the guanylyl cyclase-cGMP pathway. The data strongly suggest a protective effect of NO in maintaining normal glomerular permeability in vivo.
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| 5. |
- Dolinina, Julia, et al.
(författare)
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Sustained, delayed, and small increments in glomerular permeability to macromolecules during systemic ET-1 infusion mediated via the ETa receptor
- 2019
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Ingår i: American Journal of Physiology - Renal Physiology. - : American Physiological Society. - 1522-1466 .- 1931-857X. ; 316:6, s. 1173-1179
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Tidskriftsartikel (refereegranskat)abstract
- Dolinina J, Rippe A, Öberg CM. Sustained, delayed, and small increments in glomerular permeability to macromolecules during systemic ET-1 infusion mediated via the ETA receptor. Am J Physiol Renal Physiol 316: F1173–F1179, 2019. First published March 13, 2019; doi:10.1152/ajprenal.00040.2019.—Emerging evidence indicates that endogenous production of endothelin (ET)-1, a 21-amino acid peptide vasoconstrictor, plays an important role in proteinuric kidney disease. Previous studies in rats have shown that chronic administration of ET-1 leads to increased glomerular albumin leakage. The underlying mechanisms are, however, currently not known. Here, we used size-exclusion chromatography to measure glomerular sieving coefficients for neutral FITC-Ficoll (molecular Stokes-Einstein radius: 15–80 Å, molecular weight: 70 kDa/400 kDa) in anesthetized male Sprague-Dawley rats (n = 12) at baseline and at 5, 15, 30, and 60 min after intravenous administration of ET-1. In separate experiments, ET-1 was given together with the selective ET type A (ETA) or ET type B (ETB) receptor antagonists JKC-301 and BQ-788, respectively. At both 15 and 30 min postadministration, the glomerular sieving coefficient for macromolecular Ficoll (70 Å) was significantly increased to 4.4 x 10-5 0.7 x 10-5 (P = 0.024) and 4.5 x 10-5 0.8 x 10-5 (P = 0.007), respectively, compared with baseline (2.2 x 10-5 0.4 x10-5). Decreased urine production after ET-1 prevented the use of higher doses of ET-1. Data analysis using the two-pore model indicated changes in large-pore permeability after ET-1, with no changes in the small-pore pathway. Administration of ETA blocker abrogated the permeability changes induced by ET-1 at 30 min, whereas blockade of ETB receptors was ineffective. Mean arterial pressure was only significantly increased at 60 min, being 123 4 mmHg compared with 111 2 mmHg at baseline (P = 0.02). We conclude that ET-1 evoked small, delayed, and sustained increases in glomerular permeability, mediated via the ETA receptor.
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