Histological evaluation of the canine retinal vasculature following chronic systemic administration of basic fibroblast growth factor

The purpose of the present study was to determine if prolonged systemic arterial administration of basic fibroblast growth factor (bFGF) at a dose sufficient to enhance collateral vessel formation in the ischaemic hearts of dogs would produce retinal neovascularisation in these same animals. Adult dogs (15-25 kg) were subjected to gradual occlusion of a coronary artery and randomised to receive 1 of 3 treatments via an indwelling left atrial catheter: (1) bFGF 1.74 mg/d, 5 d/wk for 63 d (n = 7); (2) bFGF 1.74 mg/d, 5 d/wk, for 35 d followed by physiological saline, 5 d/wk, for 28 d (n = 10); or (3) physiological saline, 5 d/wk, for 63 d (n = 10). After 63 d the retinal vasculatures from these dogs were isolated and examined for capillary varicosity, neovascularisation and other histopathological signs of angiopathy. All data were collected under masked conditions. The results suggest that chronic, systemic arterial administration of bFGF stimulates neovascularisation in the ischemic myocardium, but has no significant structural or vasoproliferative effect on the nonischaemic retina of the same animal.