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Role of nitric oxide in the corpuscavernosum reactions evoked by hydrogen peroxide
A.V.Gurkovska, K.Yu.Sukhanova, V.A.Bouryi, V.F.Sagach
A.A.Bogomoletz Institute of Physiology, National Academy ofScienses of the Ukraine, KievInstitute of Applied Problems of Physics and Biophysics,National Academy of Sciences of the Ukraine, Kiev.
Abstract
Norpus 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 I2I2 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.
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© National Academy of Sciences of Ukraine, Bogomoletz Institute of Physiology, 2014-2024.
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