PT  - JOURNAL ARTICLE
AU  - J Wagner
AU  - A H Jan Danser
AU  - F H Derkx
AU  - T V de Jong
AU  - M Paul
AU  - J J Mullins
AU  - M A Schalekamp
AU  - D Ganten
TI  - Demonstration of renin mRNA, angiotensinogen mRNA, and angiotensin converting enzyme mRNA expression in the human eye: evidence for an intraocular renin-angiotensin system.
AID  - 10.1136/bjo.80.2.159
DP  - 1996 Feb 01
TA  - British Journal of Ophthalmology
PG  - 159--163
VI  - 80
IP  - 2
4099  - http://bjo.bmj.com/content/80/2/159.short
4100  - http://bjo.bmj.com/content/80/2/159.full
SO  - Br J Ophthalmol1996 Feb 01; 80
AB  - AIMS/BACKGROUND: All components necessary for the formation of angiotensin II, the biologically active product of the renin-angiotensin system (RAS), have been demonstrated in ocular tissue or vitreous and subretinal fluid. The tissue concentrations of renin were too high to be explained by admixture of blood. This raises the possibility of an intraocular RAS, independent of the RAS in the circulation. METHODS: In the present study, gene expression of RAS components in different parts of enucleated human eyes was investigated as evidence for tissue specific production. RESULTS: By using pooled tissue samples renin mRNA could be detected with the RNAse protection assay in retinal pigment epithelium (RPE) choroid, but not in neural retina or sclera. With reverse transcription polymerase chain reaction (RT-PCR), renin mRNA was detected in individual samples of RPE choroid and neural retina, and not anterior uveal tract or sclera. Angiotensinogen and angiotensin converting enzyme (ACE) gene expression could be demonstrated by RT-PCR in individual RPE choroid and neural retina samples and marginally in sclera samples. CONCLUSIONS: These results support the concept of intraocular synthesis of angiotensin II, independent of renin, angiotensin, and ACE in the circulation. Since gene expression was highest in ocular parts, which are highly vascularised, local angiotensin II may be involved in blood supply and/or pathological vascular processes such as neovascularisation in diabetic retinopathy.