J Korean Androl Soc.  1997 Jun;15(1):21-28.

Involvement of ATPase in Impaired Endothelium-Dependent Relaxation of Rabbit corpus Cavernosum Smooth Muscle Induced by Hypercholesterolemia

• Kim IK
• Ro BS
• Han JY
• Han KJ
• Kim SC

Abstract

PURPOSE: To investigate the involvement of ATPase in impaired relaxation of the cavernous smooth muscle by endothelium-dependent vasodilators in the hypercholesterolemic rabbit.
METHODS
We measured th activity of total ATPase, Na, K-ATPase, and Mg-ATPase in the cavernous tissue of New Zealand White rabbits that had received a regular diet (n=20) or a diet of 2% cholesterol (n=20) for 8 weeks. The animals were sacrificed, and cavernosal tissues were obtained.
RESULTS
Blood cholesterol was significantly higher in the cholesterol-fed group than in the control group. The contractile responses of the cavernosal strips to norepinephrine were not significantly different in the two groups, whereas the relaxation response of the cavernosal tissue to endothelium-dependent agents (acetylcholine, bradykinin) was significantly reduced in the hypercholesterolemic group. However, the relaxation response to endothelium-independent agents (papaverine, verapamil)was not significantly different in the two groups. The activities of total ATPase, MG-ATPase, and Na, K-ATPase increased significantly in the hypercholesterolemic group (p<0.05).
CONCLUSION
The impairment of endothelium-dependent relaxation of the cavernous smooth muscle does not seem to be related to ATPase activity, whereas the ATPase may be activated, at least in the early stage of atherosclerosis induced by hypercholesterolemia, to compensate for the hypercholesterolemia-induced intimal injury.

MeSH Terms

Adenosine Triphosphatases*
Animals
Atherosclerosis
Cholesterol
Diet
Endothelium-Dependent Relaxing Factors
Erectile Dysfunction
Hypercholesterolemia*
Male
Muscle, Smooth*
Norepinephrine
Rabbits
Relaxation*
Adenosine Triphosphatases
Cholesterol
Endothelium-Dependent Relaxing Factors
Norepinephrine