Effects of intravitreal injection of bevacizumab on nitric oxide levels

This study aimed to determine the possible effects of single-dose intravitreal bevacizumab on nitric oxide (NO) levels in serum and remote organs and to reveal one of the possible mechanisms in the pathophysiology of hypertension.

Thirty-eight adult New Zealand albino rabbits were divided into a control group (no injection was performed, killed on day 28 of the study), group 1 (killed on day 1 of the study), group 2 (killed on day 7 of the study), group 3 (killed on day 14 of the study), and group 4 (killed on day 28 of the study). The right eyes of the animals in groups 1-4 received an intravitreal single injection of 1.25 mg (0.05 ml) bevacizumab (Avastin), and their brain, heart, liver, kidney, and blood samples were collected. NO levels were evaluated in the serum and organ homogenates. Kidney tissues were assessed by electron microscopy.

Serum, brain, kidney, and liver NO levels significantly decreased in groups 2, 3, and 4 as compared with the control group (P<0.05). In addition, heart NO levels significantly decreased in groups 3 and 4 compared with the control group (P<0.05). There were no electron microscopic changes in the kidneys of either group.

This study demonstrated that single intravitreal injection of bevacizumab decreased NO levels in serum, brain, heart, liver, and kidneys. In addition, there were no electron microscopic changes in the kidneys.