Changes in rhodopsin kinase and transducin in the rat retina in early-stage diabetes.
To establish changes in phototransduction in diabetes, the effects of high glucose on rhodopsin kinase (RK) and transducin (G(t)), as well as recoverin, were examined in the retina of STZ-induced diabetic rats. Diabetes was induced by single intraperitoneal injection of STZ (50mg/kg) to Sprague-Dawley (SD) rats and the animals were sacrificed after 6 weeks. Immunohistochemistry (IHC) and Western blot analysis were carried out using antibodies against RK and G(talpha) (alpha subunit of G(t)) in the STZ-induced diabetic retina and the control retina. The expression level of recoverin protein was also analysed. In the diabetic retina, while the expression of RK protein increased, that of G(talpha) and recoverin proteins decreased. RK immunoreactivity (IR) appeared generally in the retina, and its signal increased in the outer limiting membrane (OLM), some rod cells in the outer segment layer (OSL) and at the tip of the outer plexiform layer (OPL) in the diabetic retina. G(talpha)-IR also appeared in the OPL and in photoreceptor layer. In the diabetic retina, G(talpha)-IR significantly decreased in the OPL, indicating RK-IR increase. This study illustrates the alterations in RK, G(talpha) and recoverin in the diabetic retina that may induce dysfunctions in phototransduction even in early-stage diabetes.
Kim
Young Hee
YH
Department of Anatomy and Neurobiology, College of Medicine, Institute of Health Science, Gyeongsang National University, Chilam-dong 92, Jinju, Gyungnam 660-751, South Korea.
Kim
Yoon Sook
YS
Noh
Hae Sook
HS
Kang
Sang Soo
SS
Cheon
Eun Woo
EW
Park
Sang Kyu
SK
Lee
Byung Ju
BJ
Choi
Wan Sung
WS
Cho
Gyeong Jae
GJ
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D015153:Blotting, Western / Q000379:methods; D001835:Body Weight / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D005136:Eye Proteins / Q000032:analysis*; D051606:G-Protein-Coupled Receptor Kinase 1; D007150:Immunohistochemistry / Q000379:methods; D008074:Lipoproteins / Q000032:analysis; D008297:Male; D011494:Protein Kinases / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D051603:Recoverin; D012160:Retina / Q000201:enzymology*; D015293:Transducin / Q000032:analysis*
D001786:Blood Glucose; D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D008074:Lipoproteins; C496733:Rcvrn protein, rat; D051603:Recoverin; D011494:Protein Kinases; D051606:G-Protein-Coupled Receptor Kinase 1; C496765:Grk1 protein, rat; D015293:Transducin