The unique expression profile of the androgen receptor gene in a rat model of neonatal cardiac hypertrophy.
Gender can influence many cardiovascular events, including cardiac hypertrophy. The presence of and dynamic changes involving androgen receptor (AR) gene expression are important confirmatory findings for androgen modulation in the pathogenesis of cardiac hypertrophy.


OBJECTIVE
To determine AR expression profile during neonatal hypertrophy and its regression process using a rat model.


METHODS
Relative mRNA levels of the AR gene were quantified at postnatal days 1, 7, 14, 21 and 28 using real time PCR.


RESULTS
A significant 10.6-fold decrease in AR transcription levels was observed at birth in neonates with cardiac hypertrophy (p < 0.05). Our analysis also showed a significant increase in AR mRNA levels at day 28, corresponding with regression of cardiac hypertrophy.


CONCLUSIONS
The AR gene demonstrated a noteworthy trend in its expression pattern. The initial down-regulation was most likely the result of increased testosterone levels induced by hyperinsulinaemia and hypoglycaemia, which were present in neonates from diabetic mothers during pregnancy. The paradoxical increase in AR at day 28 suggested a potential long term-effect of the in utero diabetic environment.
Department of Molecular and Clinical Genetics, Royal Prince Alfred Hospital, Camperdown, and Central Clinical School, The University of Sydney, Camperdown, New South Wales, Australia.
Bamini
B
Gopinath
Ronald
R
Trent
Bing
B
Yu
D000818:Animals; D000831:Animals, Newborn; D006332:Cardiomegaly / Q000151:congenital / Q000235:genetics* / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D012333:RNA, Messenger; D011944:Receptors, Androgen