Effect of tempol and tempol plus catalase on intra-renal haemodynamics in spontaneously hypertensive stroke-prone (SHSP) and Wistar rats.

Autor: Ahmeda AF; Department of Physiology, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia. aahmeda@ksu.edu.sa., Rae MG; Department of Physiology, University College Cork, Cork, Republic of, Ireland., Al Otaibi MF; Department of Physiology, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia., Anweigi LM; College of Dentistry, Princess Nourah bint Abdulrahman University, Riyadh, Kingdom of Saudi Arabia., Johns EJ; Department of Physiology, University College Cork, Cork, Republic of, Ireland.
Jazyk: angličtina
Zdroj: Journal of physiology and biochemistry [J Physiol Biochem] 2017 May; Vol. 73 (2), pp. 207-214. Date of Electronic Publication: 2016 Dec 09.
DOI: 10.1007/s13105-016-0541-1
Abstrakt: Vasoconstriction within the renal medulla contributes to the development of hypertension. This study investigated the role of reactive oxygen species (ROS) in regulating renal medullary and cortical blood perfusion (MBP and CBP respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar rats. CBP and MBP were measured using a laser-Doppler flow meter before and after intra-renal infusion of tempol, the superoxide dismutase (SOD) mimetic or tempol plus catalase, the hydrogen peroxide-degrading enzyme. Tempol infusion significantly elevated blood perfusion within the renal medulla (MBP) in both SHRSP (by 43 ± 7%, P < 0.001) and Wistar rats (by 17 ± 2%, P < 0.05) but the magnitude of the increase was significantly greater in the SHRSP (P < 0.01). When the enzyme catalase and tempol were co-infused, MBP was again significantly increased in SHRSP (by 57 ± 6%, P < 0.001) and Wistar rats (by 33 ± 6%, P < 0.001), with a significantly greater increase in perfusion being induced in the SHRSP relative to the Wistar rats (P < 0.01). Notably, this increase was significantly greater than in those animals infused with tempol alone (P < 0.01). These results suggest that ROS plays a proportionally greater role in reducing renal vascular compliance, particularly within the renal medulla, in normotensive and hypertensive animals, with effects being greater in the hypertensive animals. This supports the hypothesis that SHRSP renal vasculature might be subjected to elevated level of oxidative stress relative to normotensive animals.
Databáze: MEDLINE
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