K. Mawatari et al., EFFECTS OF SEROTONIN AND ENDOTHELIN ON THE SMOOTH-MUSCLE CELLS OF AUTOGENOUS VEIN GRAFTS, British Journal of Surgery, 84(10), 1997, pp. 1419-1424
Background The purpose of this study was to compare the effects of vas
oconstrictor substances such as 5-hydroxytryptamine (5-HT) and endothe
lin on the smooth muscle of canine femoral veins and vein grafts. Meth
ods The right canine femoral vein was grafted into the right femoral a
rtery. The left femoral vein was used as a control. In other experimen
ts to examine the effects of surgical procedures such as dissection of
the adventitia and the effects of grafting (vein-to-vein bypass), the
right femoral vein was dissected out but not removed for grafting and
an autogenous vein bypass of the right femoral vein was made using th
e left femoral vein. In all experiments, the veins were removed 4 week
s after operation and suspended in organ chambers for isometric tensio
n recording. Results Maximum contractions to endothelin were comparabl
e in control vein and vein grafts. In control vein, the maximum contra
ction to 5-HT was small, and was inhibited by both methiothepin, a 5-H
T1 and 5-HT2 antagonist, and sarpogrelate hydrochloride, a 5-HT2 antag
onist. In vein grafts 5-HT produced significantly larger contractions
than in control veins, which were inhibited by methiothepin but not by
the 5-HT2 antagonist. In veins with adventitial dissection alone and
vein-to-vein grafts, 5-HT produced small contractions which were compa
rable to those in control vein. Conclusion The larger contraction resp
onse to 5-HT in canine vein grafts may be due to an increased responsi
veness of the 5-HT1 receptor caused by grafting into the arterial circ
ulation.