[Role of nitric oxide in the corpus cavernosum reactions evoked by hydrogen peroxide].
Corpus cavernosum smooth muscle spends the majority of its time in the contracted state consisting of tonic and tetanic components. Tetanic component is a result of superposition of phasic contrations ocuring spontaneously with a frequency of 5-27/minute. Hydrogen peroxide (H2O2) in concentration of 10(-3) mol/l causes a transient increase in tetanic contraction lasting 5 to 8 minutes, followed by either recovery of spontaneous activity or inhibition of its frequency and muscle strip relaxation. 30 minutes pretreatment with the specific blocker of NO syntase, L-NAME, does not affect the intrinsic spontaneous activity parameters but enhances H2O2 evoked reaction, increasing both the amplitude and duration of the transient contraction by 41.2 +/- 14.5 and 52.5% +/- 22.8% (n=9) correspondingly. By contrast, the exogenous NO donors nitroglycerin and sodium nitroprusside, cause spontaneous activity inhibition and muscle strip relaxation resulting in the decrease of H2O2 evoked contraction and duration by 8.7 +/- 3.7 and 24.5% +/- 10.6% (n=7) correspondingly. These results suggest that tetanic contraction is an important component of corpus cavernosum smooth muscle tone which is modulated by free radical oxygen species and controlled by NO dependent mechanism.
Gurkovs'ka
A V
AV
Sukhanova
Kh Iu
KhIu
Buryĭ
V O
VO
Sahach
V F
VF
D000818:Animals; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010413:Penis / Q000187:drug effects / Q000378:metabolism*; D011817:Rabbits
D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D019331:NG-Nitroarginine Methyl Ester