Nervous influence on traumatic vasospasm in the rabbit ear artery

The effects of partial denervation, partial denervation with additional nervous blockade with bupivacaine, and total denervation achieved by amputation and replantation of the ear on traumatic vasospasm were studied in the rabbit. The central ear artery was exposed and compressed in a standardized fashion. The inner diameter was determined by in vivo microscopy using transillumination with cold light. The resulting spasm was assessed in terms of its duration, intensity (reduction of initial diameter), and severity (integrated change in diameter over time). None of the types of denervation had any influence on the vasospasm. The results suggest that the vasospasm is a local phenomenon of the vascular smooth muscle and is not modified by the nervous system.