Do the blood vessels of the antler velvet of the red deer have an adrenergic innervation?

Samples of antler velvet and pedicle skin of Red deer were snap-frozen, freeze-dried and treated with hot formaldehyde vapour. Sections (4 microns thick) were epi-illuminated with ultra-violet light. No blue-green fluorescence characteristic of adrenergic nerves was seen in sections from the antler velvet except in one castrate, although the blood vessels of the pedicle skin were well innervated. Yellow fluorescence characteristic of 5-hydroxytryptamine was present in mast cells in the velvet. The lack of a discrete adrenergic vasomotor innervation of the antler blood vessels makes it unlikely that antlers in velvet control heat loss by functioning as heat radiators.