Vascular cross-sectional area in rat mammary tumours; influence of noradrenaline. 
A double fluorescent staining technique for visualisation of blood vessels was applied to rat mammary tumours.  Rats were exposed to noradrenaline or saline and the stained vascular area was recorded.  In tumours exposed to noradrenaline, vascular staining was different from that in those exposed to saline, reflecting the possible closure of part of the vasculature in response to the drug.