Korean J Urol.  2003 Jun;44(6):592-598.

Expression of Heme Oxygenase-2 and Smooth Muscle Relaxation by Carbon Monoxide in Rat Prostate: Effects of Age and Castration

• Oh HY
• Kwon SM
• Lee JR
• Kim SI
• Choi YD
• Hong SJ

Abstract

PURPOSE: Carbon monoxide (CO), as well as nitric oxide (NO), have been proposed as potential effectors in the non-adrenergic, non-cholinergic (NANC), nerve-mediated relaxation of the prostate. Attempts were made to determine the localization and expression of heme oxygenase-2 (HO-2), and to observe the change in the relaxation of the smooth muscle induced by CO, depending on age and castration, in rat prostate glands.
MATERIALS AND METHODS
The prostate smooth muscles, isolated from young (125+/-4.5g, n=18), adult (321+/-17.8g, n=18), old (413+/-6.4g, n=18) and castrated adult (318+/-15.2g, n=18) rats, were used. The HO-2 immunohistochemistry was observed using the rabbit anti-HO-2 polyclonal antibody. The expressions of HO-2 were measured by a reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting. Polygraphy, connecting the force displacement transducer, was used to observe the relaxation effect of CO. To investigate the relaxation action of the CO mediated, to the soluble guanylate cyclase (sGC) enzyme inhibitors, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and methylene blue were added to the reaction solutions.
RESULTS
The HO-2 was located in the nerve fibers of the rat prostates. A quantitative analysis of PCR products revealed greater decreased levels of HO-2 mRNA and protein expression in the young (p<0.05) and castrated adults (p<0.05) than in the normal adult rats. The relaxation effect of CO was greater in the adult than in the young (p<0.05), old and castrated adult rats (p<0.05), but the effect was inhibited by the addition of ODQ and methylene blue in all groups (p<0.05).
CONCLUSIONS
CO has an effect on the relaxation of rat prostate smooth muscle. The expression of HO-2 in the prostate became higher with increasing age, so it is estimated the relaxation effect of CO in the older adults will be higher than with the other ages. Androgen deprivation decreases relaxation effect of CO in prostate smooth muscle.

Keyword

Muscle; smooth; Carbon monoxide; Heme oxygenase; Castration; Prostate

MeSH Terms

Adult
Animals
Blotting, Western
Carbon Monoxide*
Carbon*
Castration*
Enzyme Inhibitors
Guanylate Cyclase
Heme Oxygenase (Decyclizing)
Heme*
Humans
Immunohistochemistry
Methylene Blue
Muscle, Smooth*
Nerve Fibers
Nitric Oxide
Polymerase Chain Reaction
Prostate*
Rats*
Relaxation*
RNA, Messenger
Transducers
Carbon
Carbon Monoxide
Enzyme Inhibitors
Guanylate Cyclase
Heme
Heme Oxygenase (Decyclizing)
Methylene Blue
Nitric Oxide
RNA, Messenger