Small artery structural alterations of patients with microvascular angina (syndrome X).
1. There is increasing evidence that a substantial number of patients who suffer from angina have normal epicardial arteries (Syndrome X), and it has been suggested that these individuals have a generalized disorder of small vessels not confined to the intramyocardial vasculature. 2. Small arteries were therefore obtained from biopsies of skin and subcutaneous fat from nine normotensive patients with Syndrome X and nine matched control subjects. Vessels were dissected and mounted as ring preparations in a myograph for morphological and functional assessment. 3. Morphological measurements revealed a significant increase in media thickness/lumen diameter ratio in arteries from patients with Syndrome X. Contractile responses to U46619 were similar in arteries from patients and control subjects. Endothelium-dependent relaxation induced with acetylcholine and bradykinin was greater in arteries from patients although differences were not statistically significant. Endothelium-independent relaxation induced by forskolin and sodium nitroprusside was not different. 4. In conclusion, these data demonstrate that subcutaneous small arteries from patients with Syndrome X are characterized by increased media thickness/lumen diameter ratios, although contractile responses were normal. Additionally, endothelium-dependent relaxation was not impaired in arteries from these patients. Thus, no significant functional abnormalities were associated with the observed structural differences.
Bund
S J
SJ
University Department of Medicine, Manchester Royal Infirmary, U.K.
Tweddel
A
A
Hutton
I
I
Heagerty
A M
AM
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine / Q000494:pharmacology; D000273:Adipose Tissue / Q000098:blood supply*; D000328:Adult; D001158:Arteries / Q000473:pathology / Q000503:physiopathology; D001920:Bradykinin / Q000494:pharmacology; D046508:Culture Techniques; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D017566:Microvascular Angina / Q000473:pathology*; D008875:Middle Aged; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D012867:Skin / Q000098:blood supply*; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D011450:Prostaglandin Endoperoxides, Synthetic; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine; D001920:Bradykinin