Diabetes-induced increase of renal medullary hydrogen peroxide and urinary angiotensinogen is similar in normotensive and hypertensive rats

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Daniela Patinha (Author) Other; Joana Afonso (Author) Other; Sousa, T (Author) FMUP; Manuela Morato (Author) FFUP; Albino Teixeira, A (Author) FMUP

Journal

Title: Life Sciences

Vol. 108

Pages: 71-79

ISSN: 0024-3205

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 10 Citations

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

Other information

Authenticus ID: P-009-MSY

DOI: 10.1016/j.lfs.2014.05.011

Abstract (EN): Aims: Activation of renal renin-angiotensin system (RAS) and reactive oxygen species (ROS) are the main pathophysiological mechanisms associated with kidney injury both in diabetes and hypertension. However, the contribution to medullary damage when the two pathologies coexist has seldom been explored. Main methods: Diabetes was induced with streptozotocin in twelve week-old male Wistar and spontaneously hypertensive rats (SHR) rats; controls received vehicle. Three weeks later, systolic blood pressure (SBP), plasma and urinary angiotensinogen (AGT), renal oxidative stress and metabolic status were evaluated. Key findings: SBP was higher in SHR-controls than in Wistar-controls (200 +/- 6 and 127 +/- 3 mmHg, respectively) and decreased in SHR-diabetics but not in Wistar-diabetics (143 +/- 8 and 122 +/- 6 mmHg, respectively). Renal medullary hydrogen peroxide (H202) production was similarly increased in diabetics (Wistar: 032 +/- 0.04 and 1.11 +/- 0.10 nmol/mg protein, respectively; SHR: 0.40 +/- 0.05 and 0.90 +/- 0.14 nmol/mg protein, respectively) and positively correlated with glycemia (Wistar: r = 0.7166, SHR: r = 0.7899, p < 0.05) and urinary AGT excretion (Wistar: r = 0.8333; SHR: r = 0.8326, p < 0.05). Cortical I-1202 production was higher in SHR-controls than in Wistar-controls (1.10 +/- 0.09 and 0.26 +/- 0.04 nmol/mg protein, respectively) and diabetes induction decreased it in SHR (0.70 +/- 0.09 nmol/mg protein). Diabetes increased urinary AGT excretion by more than 7-fold and decreased plasma AGT concentration by more than 1.5-fold in both strains. Significance: Our results show that STZ-induced diabetes increases medullary H2O2 production and urinary AGT excretion with similar magnitude in normotensive and hypertensive animals. Reducing blood pressure attenuates hypertension-associated cortical damage but does not prevent medullary dysfunction.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9