The short-term effect of pentoxifylline on rabbit choroidal blood flow.

This study evaluates the effect of different doses ofpentoxifylline on rabbit choroidal blood flow (CBF). Sixteen albino rabbits of both sexes, weighing 2.0-3.0 kg, were randomly separated into four groups. The first group of rabbits received 2 ml normal saline injection through the ear vein. They served as the control group (group n). Three different doses of pentoxifylline, 1 mg/kg, 5 mg/kg, and 10 mg/kg, were injected intravenously to groups p1, p5 and p10, respectively. By means of a laser Doppler flowmeter, the blood cell flux (PF), velocity, and the concentration of moving blood cells (CMBC) were recorded simultaneously. The laser probe was advanced through the pars plana and positioned near the retinal surface. The mean arterial pressure was recorded at the same time. There was a significant increase in PF at 1, 5 and 10 min in group p10 rabbits compared with the control group (p=0.0005, 0.0416, and 0.0087, respectively). The velocity increased at 5 min in group p5 rabbits (p=0.0082) and at 1, 5 and 10 min in group p10 rabbits (p=0.0188, 0.0080, and 0.0207, respectively) as compared with the controls. The CMBC decreased after injection of pentoxifylline and reached statistical significance at 5 and 10 min in group p5 rabbits (p=0.0019 and 0.0046, respectively) and at 5 min in group p10 rabbits (p=0.0447). These results show that larger doses of pentoxifylline (10 mg/kg) increased the CBF of rabbits. This effect was achieved primarily by an increase in blood cell velocity.