Altered growth factor expression in the aging penis: the Brown-Norway rat model.
The objective of the present study was to evaluate age-related changes in the protein and gene expression of modulators of erectile function (nitric oxide [NO] and endothelin-1 [ET-1]) and growth factors such as transforming growth factor (TGF-beta1) and vascular endothelial growth factor (VEGF) in the penile tissue of Brown-Norway (BN) rats. Young and old BN male rats were euthanized, and the penile tissue was processed for immunohistochemical and molecular analyses. Total RNA was extracted, and an Access reverse transcription-polymerase chain reaction (RT-PCR) system was used for messenger RNA (mRNA) expression analysis. Immunohistochemical studies showed a decreased expression of endothelial nitric oxide synthase (eNOS) protein and an increased staining for ET-1. Quantitative analysis of PCR products revealed decreased levels of VEGF mRNA expression in the old population of rats. The most significant decrease was detected between bands corresponding to splice forms 164 (21%) and 120 (18%). The observed alterations in the gene expression of growth factors such as VEGF may contribute to the abnormal age-related morphological and physiological alterations in the erectile tissue.
Rajasekaran
Mahadevan
M
Division of Urology, University of California San Diego Medical Center, 92103-8897, USA. mrajasek@ucsd.edu
Kasyan
Armen
A
Jain
Amita
A
Kim
Sae-Woong
SW
Monga
Manoj
M
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001391:Azo Compounds; D016228:Endothelial Growth Factors / Q000032:analysis / Q000235:genetics*; D019332:Endothelin-1 / Q000032:analysis / Q000235:genetics; D004801:Eosine Yellowish-(YS); D007172:Erectile Dysfunction / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology; D007150:Immunohistochemistry; D008222:Lymphokines / Q000032:analysis / Q000235:genetics*; D008297:Male; D008739:Methyl Green; D023421:Models, Animal; D017942:Nitric Acid / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000235:genetics; D052250:Nitric Oxide Synthase Type III; D010413:Penis / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011914:Rats, Inbred BN; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000235:genetics*; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D001391:Azo Compounds; D016228:Endothelial Growth Factors; D019332:Endothelin-1; D008222:Lymphokines; D012333:RNA, Messenger; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C017768:trichrome stain; D017942:Nitric Acid; D008739:Methyl Green; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D004801:Eosine Yellowish-(YS)