The expression of vascular endothelial growth factor in skeletal muscle of patients with sleep disorders.
An increased capillary network has been observed in skeletal muscle of patients with restless legs syndrome (RLS) and obstructive sleep apnea syndrome (OSAS). This finding could be due to upregulation of growth factors responsible for angiogenesis. The aim of the study was to examine the occurrence and localization of VEGF and capillary proliferation in skeletal muscle of RLS (n = 12) and OSAS (n = 12) patients and controls (n = 11). Double-immunofluorescence staining for capillaries (CD31) and VEGF, and proliferating cells (Ki-67), was carried out on biopsies taken from the tibialis anterior. The percentage of capillaries expressing VEGF (CD31,VEGF(+)) was significantly higher in OSAS and RLS patients compared with controls. The percentage of proliferating capillaries (CD31,Ki-67(+)) was significantly higher in OSAS patients compared with controls. Our study shows the occurrence of proliferation of endothelial cells in skeletal muscle in RLS and OSAS, supporting an upregulation of VEGF located in capillaries, probably due to local hypoxia.
Wåhlin-Larsson
Britta
B
School of Health and Medical Sciences, Orebro University, Orebro, Sweden. bwl@du.se
Ulfberg
Jan
J
Aulin
Karin Piehl
KP
Kadi
Fawzi
F
D000328:Adult; D001706:Biopsy; D002196:Capillaries / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D012016:Reference Values; D012148:Restless Legs Syndrome / Q000378:metabolism; D020181:Sleep Apnea, Obstructive / Q000378:metabolism; D012893:Sleep Wake Disorders / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
D019394:Ki-67 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A