[The relationship between endothelin receptors and chronic venous insufficiency of lower extremities].
OBJECTIVE
To investigate the effect of endothelin receptors in chronic venous insufficiency (CVI) in lower extremities.


METHODS
Ten cases of varicose veins from CVI patients (as case group) and ten cases of non-varicose veins (as control group) were investigated in this study. The two groups were divided into two groups respectively: endothelium-intact group and de-endothelium groups. The vasoconstriction mediated by endothelin A (ETA) and endothelin B (ETB) receptors was recorded with myography. The distribution of ETA and ETB receptors was detected by immunohistochemistry method.


RESULTS
Endothelin-1 (ET-1) and sarafotoxin 6c (S6c) induced concentration-dependent contraction in the veins. In endothelium-intact veins, the E(max) and pD(2) of contraction curve induced by ET-1 were 132.30% +/- 43.42% and 6.03 +/- 0.35, respectively in control group;and were 19.24% +/- 12.94% and 6.78 +/- 0.46, respectively in case group. The E(max) and pD(2) in case group were much lower than in control group (P < 0.05). The E(max) and pD(2) induced by S6c were 30.10% +/- 12.90% and 6.54 +/- 0.36, respectively in control group, and were 9.61% +/- 1.32% and 6.75 +/- 0.29, respectively in case group; The E(max) in case group was lower than in control group (P < 0.05). In de-endothelium veins, E(max) and pD(2) of S6c were 146.18% +/- 32.33% and 6.50 +/- 0.17 in control group, and 32.93% +/- 3.00% and 6.69 +/- 0.39 in case group; The E(max) in case group was significantly lower than in control group (P < 0.05). ETA receptors was located in endothelium mainly, and ETB receptors in smooth muscle cells mainly. The sites of both ETA and ETB receptors were decreased in case group obviously.


CONCLUSIONS
The contraction mediated by ETA receptor and ETB receptor was decreased with a decrease of ETA receptor and ETB receptor sites in varicose veins of CVI. The contraction insufficiency and down-expression of ETA receptor and ETB receptor are correlated with CVI.
Yang
Lin
L
Department of General Surgery, the First Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an 710061, China. yl581@sohu.com
Qi
Guang-yu
GY
Cao
Yong-xiao
YX
Liu
Jing
J
Zhao
Ming
M
D000328:Adult; D019332:Endothelin-1 / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D017466:Receptors, Endothelin / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014689:Venous Insufficiency / Q000503:physiopathology*; D014757:Viper Venoms / Q000494:pharmacology
D019332:Endothelin-1; D017466:Receptors, Endothelin; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C057354:sarafotoxins s6