Premium
Divergence of renal vascular endothelial growth factor mRNA expression and protein level in post‐ischaemic rat kidneys
Author(s) -
Vannay Ádám,
Fekete Andrea,
Ádori Csaba,
Tóth Tibor,
Losonczy György,
László Lajos,
Vásárhelyi Barna,
Tulassay Tivadar,
Szabó András
Publication year - 2004
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2004.027516
Subject(s) - vascular endothelial growth factor , kidney , endocrinology , messenger rna , medicine , angiogenesis , immunohistochemistry , biology , western blot , hypoxia inducible factors , vegf receptors , biochemistry , gene
Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis and vascular protection. Synthesis of VEGF is induced by hypoxia and different cytokines including interleukin‐6 (IL‐6) and interleukin‐1β (IL‐1β). However, post‐ischaemic alterations of this growth factor in the kidney are incompletely known. To determine VEGF synthesis in renal ischaemia/reperfusion (I/R) injury unilateral warm ischaemia was induced by cross‐clamping the left renal pedicle for 55 min followed by 2 and 24 h of reperfusion (T 2 and T 24 kidneys; n = 6 in each group). Sham‐operated, non‐clamped animals served as controls ( n = 6). Renal VEGF, IL‐6 and IL‐1β mRNA expression were determined by reverse transcription‐polymerase chain reaction (RT‐PCR). VEGF protein level and distribution were determined by Western blot and immunohistochemical analysis. Immunohistochemistry revealed prominent VEGF staining in the outer medulla of control, T 2 and T 24 kidneys. VEGF immunoreactivity accumulated at the basolateral area of tubular epithelial cells in T 2 kidneys, while it was diffuse in control and T 24 kidneys. VEGF protein levels were increased 2‐ to 3‐fold in T 2 and T 24 kidneys (both P < 0.01 versus controls), while VEGF mRNA expression remained unchanged. IL‐6 mRNA expression was increased ( P < 0.01 versus controls) in T 2 kidneys, while IL‐1β mRNA expression remained unchanged. Increased VEGF protein levels but not mRNA expression suggests that during renal I/R injury VEGF synthesis in kidneys – unlike in other organs – is primarily regulated at a post‐transcriptional level. As IL‐6 mRNA expression increased simultaneously with VEGF protein levels, the post‐ischaemic regulation of IL‐6 and VEGF synthesis might be interrelated in rat kidney.