Study of inhibitory effects of an antiangiogenic somatostatin-camptothecin conjugate on laser-induced choroidal neovascularization in rats.
OBJECTIVE
To evaluate the ocular toxicity and efficacy of intravitreal camptothecin-somatostatin conjugate (JF-10-81), a somatostatin type 2 receptor-directed, antiangiogenic compound.


METHODS
Part 1: New Zealand albino rabbits (except for controls) were injected intravitreally with conjugate at various concentrations. Preoperative and postoperative ocular examinations and electroretinography were performed until animals were killed for histology. Part 2: Long-Evans pigmented rats had choroidal neovascularization (CNV) induced by argon laser. One eye per animal was injected with concentration 10M (safe dose), whereas the other eyes were controls and received 30 microL of sterile water at different time intervals after laser application. Fluorescein angiography was performed at various time points to evaluate the lesions and confirm presence of CNV. Animals were euthanized. The eyes were immediately enucleated and prepared for histologic examination.


RESULTS
Part 1: No clinical changes were seen in groups receiving 10(-8)M, 10(-7)M, 10(-6)M, and 10(-5) M of conjugate. Electroretinography showed decreasing b-wave amplitude in groups receiving 10(-4) M and 10(-3) M; cataracts also developed in these eyes. Part 2: Fluorescein angiography revealed that intravitreal injection of somatostatin conjugate JF-10-81 favorably affected the development of CNV when the treatment was performed at least 1 week after the laser application. These results were statistically significant. Histologic analysis results of eyes treated 2 weeks after laser application also showed significant benefit.


CONCLUSIONS
Part 1: Camptothecin-somatostatin conjugate injected intravitreally appeared safe at concentrations of 10(-5)M or less. Part 2: Conjugate JF-10-81 at a concentration of 10(-5)M administered intravitreally 1 to 3 weeks after laser demonstrated statistically significant efficacy in the treatment of choroidal neovascularization.
Bezerra
Yanno
Y
Department of Ophthalmology, Tulane University Health Sciences Center, New Orleans, Louisiana 70112-2699, USA.
Fuselier
Joseph A
JA
Peyman
Gholam A
GA
Oner
Hakan
H
Drouant
George
G
Coy
David H
DH
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D002166:Camptothecin / Q000627:therapeutic use* / Q000633:toxicity; D020256:Choroidal Neovascularization / Q000188:drug therapy* / Q000503:physiopathology; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004596:Electroretinography; D005451:Fluorescein Angiography; D007267:Injections; D053685:Laser Therapy; D008297:Male; D011817:Rabbits; D051381:Rats; D020318:Rats, Long-Evans; D012160:Retina / Q000187:drug effects / Q000503:physiopathology; D013004:Somatostatin / Q000627:therapeutic use* / Q000633:toxicity; D014822:Vitreous Body
D020533:Angiogenesis Inhibitors; D013004:Somatostatin; D002166:Camptothecin