Vascular reactivity after balloon angioplasty in an atherosclerotic rabbit.

Abstract

Alterations in vessel wall reactivity (VR) at or adjacent to the dilation site after balloon angioplasty (BA) may vary according to the inflation protocol and the time after angioplasty and may influence outcome. In 64 atherosclerotic rabbit femoral arteries, we evaluated VR after BA with intravenous ergonovine (ERGO) (40 ,ug/min for 5 minutes) and intra-arterial nitroglycerin (NTG) (2,500 ,ug single bolus)

Effect of chronic subcutaneous or intramural administration of heparin on femoral artery restenosis after balloon angioplasty in hypercholesterolemic rabbits. A quantitative angiographic and histopathological study.

“…Details of this experimental model have been published previously. [17][18][19] Induction of Focal Atherosclerosis Fifty-nine male New Zealand White rabbits (weight, 4.0±0.4 kg) were anesthetized with ketamine (50 mg/kg i.m.) and xylocaine (5 mg/kg i.m.).…”

Potentiation of the vasospastic response to angioplasty by pretreatment with fluoxetine. A study in the atherosclerotic rabbit.

“…This finding is consistent with the presence of vasospasm at the angioplasty site in the fluoxetine-treated rabbits and would appear to be in conflict with data published earlier from our laboratory when we reported that vasospasm does not occur at the angioplasty site after angioplasty. 23 In this study, a balloon matched to the lumen size was used. Histologically, there was less medial damage than reported previously, and thus, the vessel was presumably able to react to the intense vasospastic stimulus that was present in this study.…”

“…Often these processes occur in concert, and the individual effects of each are difficult to separate. 118 Vasospasm after angioplasty has been identified in both animals 19 " 23 and patients. 24 Its contribution to acute vessel closure is suggested by reversal of the acute occlusion in some cases with vasodilators.…”

Effects of serotonin-receptor blockade on angioplasty-induced vasospasm in an atherosclerotic rabbit model.

“…In our anesthetized rabbits, it is likely that the studied vessels are maximally dilated at baseline, as demonstrated by their lack of further dilatation to infused nitrogrycerin. 26 Thus, any vasodilatory effect of lowdose serotonin on normal vessels may be masked. Similarly, others have reported that the S 2 -mediated contractile effects of serotonin may predominate in vivo, 27 and serotonin-induced endothelium-dependent relaxation may not be apparent unless unmasked by an S 2 -receptor antagonist.…”

“…35 We have shown previously in this model that dilatation to 10 arm with an appropriately sized balloon causes moderate degrees of medial necrosis and patchy areas of acellularity in the treated areas 32 and that this may render the dilatation site unresponsive to ergonovineinduced vasoconstriction. 26 Of note, treated sites can regain some responsiveness to vasoconstrictors with time, 26 particularly to serotonin. 36 Others have suggested that treated sites do retain the ability to vasoconstrict when treated with appropriately sized balloons at relatively low inflation pressures.…”