Augmented retinal endothelin-1, endothelin-3, endothelinA and endothelinB gene expression in chronic diabetes.
OBJECTIVE
Endothelins (ETs) belong to a family of vasoactive peptides implicated in several disorders of the microvasculature. In the present study, we investigated ET-1 and ET-3 peptide mRNAs and ETA, ETB receptor mRNAs in the retina of diabetic BB/W rats and age-matched, non-diabetic control animals, following six months of diabetes.


METHODS
Total mRNA was extracted from each retina and was subjected to reverse transcriptase polymerase chain reaction for ET-1, ET-3, ETA and ETB. Simultaneously, beta-globin was amplified and used as a housekeeping gene. The products were analyzed on agarose gels and the specificity of the amplification was established by hybridization with amplification-specific biotinylated oligoprobes. For quantification, the products from the linear phase of amplification were subjected to serial dilution slot-blot hybridization and densitometry.


RESULTS
ETs and their receptor mRNA expressions were present in the retina. Retinas from the diabetic animals showed significant increases in ET-1, ET-3 ET(A), ET(B) mRNA expressions compared to those from control rats.


CONCLUSIONS
These findings indicate that retinal ET-1, ET-3, ET(A) and ET(B) mRNA expression in increased in the chronically diabetic BB/W rat. Augmented gene expression of ETs and their receptors potentially may be of importance in the pathogenesis of retinal microangiopathy in diabetes.
Chakrabarti
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Department of Pathology, University of Western Ontario, London, Canada. schakrab@julian.uwo.ca
Gan
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Merry
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Karmazyn
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Sima
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D000818:Animals; D015139:Blotting, Southern; D002908:Chronic Disease; D017931:DNA Primers / Q000737:chemistry; D016373:DNA, Antisense / Q000737:chemistry; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000378:metabolism*; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism; D019334:Endothelin-3 / Q000235:genetics / Q000378:metabolism; D016232:Endothelins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D008297:Male; D016133:Polymerase Chain Reaction; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011913:Rats, Inbred BB; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin / Q000235:genetics* / Q000378:metabolism; D012160:Retina / Q000378:metabolism
D017931:DNA Primers; D016373:DNA, Antisense; D019332:Endothelin-1; D019334:Endothelin-3; D016232:Endothelins; D012333:RNA, Messenger; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin; D012313:RNA