Retinal And Systemic Side-Effects Studies Following Intravitreal Injection Of Bevacizumab (AVASTIN) In Adult Mice

Objective: To evaluate the toxic effects on the mouse retina, brain, cardiac, liver and kidney tissue by an intravitreal Avastin in adult mice.Methods: Select 60 healthy male Wistar rats, which were randomly divided into four groups (of 15 in each group): control group, there experimental group (①0.75mg,②1.25mg,③2.5mg). The right eyes were designated as the study eyes and received 2μl of Avastin(Avastin eye) , and the left eyes served as a control and received the same volume of saline intravitreally in the Avastin group (saline eye). The control group was injected intravitreally with 2μl of saline into two eyes. All the groups were scheduled to be terminated five mice at 1st, 4th, 7th days. Sections were stained with hematoxylin-eosin (H&E), Apoptosis was detected in retina, brain, cardiac, liver and kidney using TUNEL staining.Results: 1. A similar morphology of retina HE staining could be observed in Avastin group. The retina tissue is structural integrity, the inner nuclear layer, nuclear layer, cone cells, rod cells are in well stratified. The HE staining shows of the experimental eyes were of normal pattern and morphology and did not differ from the control eyes throughout the 1st, 4th, 7th days. 2. The retina TUNEL staining shows that the TUNEL positive cells were detected only in retinal ganglion cell throughout the follow-up period in Avastin group. The experimental eyes of apoptosis index compared with control eyes have no statistical significance (P>0.05). The apoptosis index also have no statistical significance (P>0.05) between the 1st, 4th, 7th days in each different experimental eyes group.3. A similar morphology of brain HE staining could be observed in Avastin group and control group. The nucleus of cerebral cortical neuron is clear.cell structure is integrity.The HE staining shows of the Avastin group were of normal pattern and morphology and did not differ from the control group throughout the 1st, 4th, 7th days. A few TUNEL positive cells can be found in brain tissue.4. A similar morphology of cardiac HE staining could be observed in Avastin group and control group. The nucleus of cardiac muscle cell is clear.cell structure is integrity.The HE staining shows of the Avastin group were of normal pattern and morphology and did not differ from the control group throughout the 1st, 4th, 7th days. The TUNEL positive cells cannot be found in cardiac tissue.5. A similar morphology of liver HE staining could be observed in Avastin group and control group. The liver tissue is structural integrity ,hepatic lobule with a fairly complete structure , hepatic cell show a radial pattern around central vein ,hepatic sinusoids is clear ,hepatic cord is in well stratified. The HE staining shows of the Avastin group were of normal pattern and morphology and did not differ from the control group throughout the 1st, 4th, 7th days. The TUNEL positive cells cannot be found in liver tissue.6. A similar morphology of kidney HE staining could be observed in Avastin group and control group. Glomerulus is in normomorph, the renal tubular epithelium is in well stratified, renal tubule is structural intergrity.The HE staining shows of the Avastin group were of normal pattern and morphology and did not differ from the control group throughout the 1st, 4th, 7th days. The TUNEL positive cells cannot be found in kidney tissue.Conclusions: 2.5mg intravitreal Avastin does not have obvious toxic effects on the mouse retina, brain, cardiac, liver and kidney tissue.