摘要
Abstract
Objective To cladfy the dependence of neural nitric
oxide synthase mRNA (nNOSmRNA) and endothelial
nitric oxide synthase mRNA (eNOSmRNA) on
androgens (testosterone [T] and dihydrotestosterone
[DHT]).
Methods 160 male Sprague Dawley (SD) rats were
divided into Groups A (56 rats, 5 weeks old), B (50
rets,10 weeks old) and C (54 rats, 58 weeks old).
Groups A, B and C were all subdivided respectively
into five Subgroups. Subgroup 1: intact osntrels;
Subgroup 2: castrated; Subgroup 3: castrated with
testosterone ubdecanoate 25 mg/kg·mon-1,
intramuscular injection, Subgroup 4: castrated with
testosterone undecanoate 50 mg/kg·mon-1,
intramuscular injection and Subgroup 5: treated with
finaeteride 4.5 mg/kg·day-1, orally. Four and ten
weeks after treatments described above, one half of
the rats were killed. Serum samples were token for
measurements of T, free testosterone (FT) and DHT
by raclioimmunoassay. Penile samples were treated
with liquid nitrogen and then stored at-80℃.
nNOSmRNA and eNOSmRNA were detected by
semiquantitative reveres-transcription polymerase chain
reaction (RT-PCR) and Dot blot.
Resulte There was no significant difference between
Subgroup 1 and Subgroup 2 or Subgroup 5 in all
Groups A, B and C. The expression of penile
eNOSmRNA of Group A was significantly increased (4
weeks model) (P＜0.05) or increased (10 weeks
model) (P＞0.05) in Subgroup 2 or 5 compared with
those in Subgroup 1.There wes no significant
difference between Subgroup 1 and Subgroup 2 or
Subgroup 5 of Group B in 4 weeks model (P＞0.05).
There was an elevation when animals were castrated or
treated with finasteride in the 10 weeks model.The
expreseion of penile eNOSmRNA of Group C was
significantly increased (10 weeks model) (P＜0.05)
or increased (4 weeks model) in Subgroup 2 compared
with those in Subgroup 1.The production of
eNOSmRNA in Subgroup 5 was also increased
(including 4- and 10-week models). When T was
supplied for castration, the penile eNOSmRNA was
desreased to some extent; the greater the dose of T
given, the lower penile eNOSmRNA was observed.
Conclusions The expression of eNOSmRNA in SD
rat penile tissue increases while T or DHT diminishes.
Sometimes androgens medaulate penile eNOSmRNA in
opposite directions. There is no srrelation between the
expression of nNOSmRNA and androgens (including T
and DHT) . Androgens give rise to penile erection
probably not via the NOS pathway.关键词
androgen/penis/corpus cavernosum/nitric oxide synthaseKey words
androgen/penis/corpus cavernosum/nitric oxide synthase
