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 systemi c arterial administration of basic fibroblast growth factor (bFGF) at a dose sufficient to enhance collateral vessel formation in the ischae mic hearts of dogs would produce retinal neovascularisation in these s ame 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 physiologi cal 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 thes e dogs were isolated and examined for capillary varicosity, neovascula risation and other histopathological signs of angiopathy. All data wer e collected under masked conditions. The results suggest that chronic, systemic arterial administration of bFGF stimulates neovascularisatio n in the ischemic myocardium, but has no significant structural or vas oproliferative effect on the nonischaemic retina of the same animal.