Objective To observe the distribution and concentration of 125I-nerve growth factor (NGF) in rabbitsprime; eyes after intravitreal injection and posterior juxtascleral injection.Methods Intravitreal injection(group A) and posterior juxtascleral injection (group B) were performed with the dosage of 30mu;g/100mu;l 125I-NGF on left and right eyes in 45 white rabbits respectively. The gamma;-counts and the concentration of 125I-NGF (％ID/g) of each ocular tissue was determined 15 and 30 minutes, and 1,3,6,12,24,and 48 hours after injection. Results The 125I-NGF diffusion in group A was faster in ocular content and ocular inner wall. The vitreous content of 125I-NGF decreased gradually in group A, the curve changes in other eye tissues were normal. The concentration of 125I-NGF reached the peak 3 hours after injection in aqueous humor, iris and ciliary body, retina, and choroids, but 6 hours after injection in sclera and 8 hours in cornea. The changes of concentration of 125I-NGF in group B showed normal curve change. The peak time in group B were all 6 hours in all the tissues except aqueous humor (3 hours). Except the high concentration in vitreous body caused by intravitreal injection, the concentration of 125I-NGF in retina was the highest in group A. Conclusion Intravitreal injection of 125I-NGF can gain higher concentration in each ocular tissue than posterior juxtascleral injection, especially in retina. So intravitreal injection of NGF is a better ocular delivery method to treat the ocular fundus diseases.
Axon guidance molecules, slit glycoprotein (Slit) and Roundabout receptors (Robo) were firstly identified in the central neural system of Drosophila melanogaster. The Slit-Robo signal plays a crucial role in axon guidance, inflammation, tumor metastasis and angiogenesis, of which the role of Slit2-Robo pathway in angiogenesis has drawn a greater attention and still remains conflicting. Herein, we provide a review on the role of Slit2-Robo pathway in ocular angiogenesis and vascularization of other organs and systems. We hope this review will be the basis of further study on the mechanism of Slit2-Robo signaling on angiogenesis and provide new target for the therapy on ocular vascular disease