mRNA and protein expression of nitric oxide synthase and adrenoceptor alpha 1 in young and old rat penile tissues.
OBJECTIVE
To investigate alterations of neuronal structure and the mRNA expression of nitric oxide synthase (NOS) and adrenoceptor alpha 1 in young and old rat penile tissues, and assess the importance of these factors in erectile dysfunction (ED) associated with ageing.


METHODS
NOS was determined in the pelvic ganglia of 32 rats using nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining. Adrenergic neurons were identified by histofluorescence staining. The gene expression for NOS and for adrenoceptor alpha 1 was investigated in corporal tissue by differential reverse transcriptase-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. b-actin was used as an internal standard in each tube to quantify the baseline gene expression.


RESULTS
The following changes occurred in old rats: (i) an increase of lipofuscin and a decrease in both bNOS-containing neurons and fluorescent adrenergic neurons in the pelvic ganglia; (ii) significantly less expression of NOS mRNA than in young rat penile tissues; and (iii) no significant alteration in adrenoreceptor alpha 1 mRNA expression.


CONCLUSIONS
The fewer adrenergic and NOS-containing neurons and neurotransmitters in pelvic ganglia from old rats may explain the enhanced penile smooth muscle tone previously reported in older impotent men. Furthermore, lower mRNA expression of NOS may be associated with structural and functional changes associated with ageing penile tissue.
Dahiya
R
R
Department of Urology, University of California, San Francisco and VA Medical Center, 94121, USA.
Lin
A
A
Bakircioglu
M E
ME
Huang
S T
ST
Lue
T F
TF
D000367:Age Factors; D000818:Animals; D007172:Erectile Dysfunction / Q000209:etiology / Q000378:metabolism; D007001:Hypogastric Plexus / Q000378:metabolism; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010413:Penis / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*
D012333:RNA, Messenger; D018340:Receptors, Adrenergic, alpha-1; D019001:Nitric Oxide Synthase