Captopril inhibits capillary degeneration in the early stages of diabetic retinopathy.
OBJECTIVE
This study was conducted to examine the effect of angiotensin-converting enzyme (ACE) inhibitors on the development of early stages of diabetic retinopathy.


METHODS
Rats were made diabetic by injection of streptozotocin and treated with the ACE inhibitor captopril and the AT1 antagonist losartan. The extent of capillary degeneration and leukostasis in the retina were determined.


RESULTS
Acellular capillaries and pericyte ghosts in the retina of diabetic animals were increased by approximately two-fold after 8 months of diabetes compared with the nondiabetic control, and captopril completely inhibited this capillary degeneration. Captopril and losartan also inhibited hyperglycemia-induced leukostasis at 6 weeks and 1 week in the retinal vasculature, respectively. In cultured retinal endothelial cells, angiotensin II-induced VCAM-1 expression was inhibited by losartan.


CONCLUSIONS
Inhibition of the renin-angiotensin system can block retinal capillary degeneration and inflammation in the early stages of diabetic retinopathy.
Zhang
Jin-Zhong
JZ
Department of Ophthalmology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA. jinzhong_zhang@bausch.com
Xi
Xia
X
Gao
Ling
L
Kern
Timothy S
TS
D000804:Angiotensin II / Q000494:pharmacology; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D002196:Capillaries / Q000187:drug effects* / Q000473:pathology; D002216:Captopril / Q000494:pharmacology*; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000097:blood; D003930:Diabetic Retinopathy / Q000473:pathology*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006943:Hyperglycemia / Q000150:complications; D018921:Leukostasis / Q000209:etiology / Q000517:prevention & control; D019808:Losartan / Q000494:pharmacology; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D012171:Retinal Vessels / Q000187:drug effects / Q000473:pathology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis / Q000187:drug effects
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D001786:Blood Glucose; D019010:Vascular Cell Adhesion Molecule-1; D000804:Angiotensin II; D002216:Captopril; D019808:Losartan