연구에서는 고혈당이 시각의 dopaminergic 및 cholinergic system에 미치는 영향을 알아보기 위하
여 streptozotocin (STZ)으로 유도한 당뇨병 모델 흰쥐의 망막에서 tyrosine hydroxylase (TH)와 choline acetyltransferase
(ChAT)의 변화를 알아보았다. 당뇨병은 250~300 g Sprague-Dawley (SD) 흰쥐에 50 mg/kg STZ을 복
막내 주사하여 유도하였고 6주 후에 희생시켰다. H & E 염색을 통하여 정상쥐와 당뇨쥐 망막의 형태학적인 변
화를 관찰하였고, 면역조직화학법과 western blotting을 이용하여 TH와 ChAT 단백질의 발현과 변화를 분석하였
다.
당뇨병 유발 6주 후 흰쥐의 망막에서 뚜렷한 형태학적인 변화는 나타나지 않았으나 TH와 ChAT의 단백질
발현과 면역반응성의 유의적인 감소가 확인되었다.
본 연구는 TH와 ChAT의 변화가 초기 당뇨 흰쥐 망막의 시각시스템변화와 연관되어 있음을 시사한다.To investigate the effect of hyperglycemia on the visual system, we investigated the retinal
dopaminergic and cholinergic systems using tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) in the rat
retinas of streptozotocin (STZ)-induced diabetes. Diabetes was induced by a single intraperitoneal injection of STZ (50
mg/kg) to Sprague-Dawley rats (250~300 g). We first analyzed morphologic thickness changes in the several retinal
layers of 6-week-old control and STZ-diabetic rats after H & E staining. To confirm whether TH and ChAT protein
expressions changed, we carried out immunohistochemistry analysis and Western blotting. After induction of diabetes,
significant changes were not shown in the retinal thickness at 6 weeks. TH and ChAT immunoreactivities were clearly
detected in amacrine cells and sublaminas in the inner retina of both control and diabetic rats, showing continuously
reduced positive amacrine cells in the retinas during diabetes. In addition, the decline in TH and ChAT protein
expression was already present to a significant extent in the retina at 6 weeks in early diabetes. Our present study
demonstrates the possibility that the observed alterations in TH and ChAT in the diabetic retina may cause the visual system changes in the retinal pathophysiology associated with diabetes mellitus.