Comparative study of functional responses and morphometric state of distal radial arteries in male and female.
BACKGROUND
Differences can exist in terms of physiology and morphology of blood vessels on the basis of gender. Radial artery is now considered to be the second choice for coronary artery bypass grafting. However, there is a lack of comparative studies on the function and morphometery of radial arteries in female and male patients.


METHODS
Radial arteries from 9 female and 9 male patients undergoing coronary artery bypass grafting were used to compare the effects of vasoconstrictors, noradrenaline and 5-hydroxytryptamine, as well as the influence of endothelium-dependent (with methacholine) and endothelium-independent (with sodium nitroprusside) relaxations. Furthermore, morphomteric measurements of smooth muscle thickness, lumen perimeter, lumen area, and intima area (including plaque) of distal radial arteries from female and male patients were also made.


RESULTS
Radial arteries from female patients when compared to male patients were significantly more sensitive to the actions of noradrenaline, and somewhat more sensitive towards the actions of 5-hydroxytryptamine. However, no significant differences were found between the relaxant effects of methacholine in radial arteries of female and male patients. In contrast, radial arteries from female patients when compared to male patients were significantly less sensitive to the relaxant effects of sodium nitroprusside. Morphometric measurements of blood vessels from female and male patients revealed that vessels obtained from female patients had a smaller lumen area and perimeter than vessels from male patients. In contrast, there were no significant differences between tunica intima area (including plaque area) or smooth muscle thickness in radial arteries of female patients when compared to male patients. However, the radial arteries from female patients had a significantly greater ratio of tunica intima area (including plaque) to lumen area when compared with radial arteries from male patients.


CONCLUSIONS
Differences exist between the functional behavior and morphometery of radial arteries of female and male patients. It is possible that postbypass, radial artery graft may show different characteristics in female versus male patients.
Mong
Kam
K
Discipline of Surgery, Health Care Corporation of St. John's, St. John's, Newfoundland, Canada.
Duggan
Jennifer A
JA
Tabrizchi
Reza
R
D000368:Aged; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D017534:Radial Artery / Q000033:anatomy & histology* / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D012737:Sex Factors; D017539:Tunica Intima / Q000187:drug effects / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects / Q000502:physiology
D014662:Vasoconstrictor Agents; D016210:Methacholine Chloride; D009599:Nitroprusside; D012701:Serotonin; D009638:Norepinephrine