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Effects of some divalent cations on nitrergic relaxations in the mouse corpus cavernosum
Author(s) -
Ertu Peyman Uçar,
Büyükafsar Kansu,
Kumcu Eda Karabal,
Göçmen Cemil,
Seçilmis Ata,
Singirik Ergin,
Dikmen Atilla,
Baysal Firuz
Publication year - 2001
Publication title -
fundamental and clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 73
eISSN - 1472-8206
pISSN - 0767-3981
DOI - 10.1046/j.1472-8206.2001.00045.x
Subject(s) - chemistry , guanethidine , acetylcholine , endocrinology , contraction (grammar) , sodium nitroprusside , medicine , phenylephrine , inhibitory postsynaptic potential , verapamil , divalent , nitric oxide , stimulation , calcium , biology , organic chemistry , blood pressure
Acute effects of some divalent cations (Cd 2+ , Ni 2+ , Co 2+ , Zn 2+ , Mn 2+ and Sn 2+ ) were investigated on neurogenic and endothelium‐dependent relaxations in the isolated mouse corpus cavernosum. Neither neurogenic nor endothelium‐dependent relaxation was affected by cations at the concentrations used (up to 100 μ M ), except Cd 2+ . Although Cd 2+ (20 and 40 μ M ) did not cause any significant alteration in the acetylcholine‐ (ACh) or sodium nitroprusside‐ (SNP) induced relaxation, it inhibited electrical field stimulation‐ (EFS) produced relaxation significantly. Zn 2+ and selenium could not reverse this inhibitory action. Cd 2+ did block the EFS‐evoked guanethidine‐sensitive contraction in the presence of N G ‐nitro‐ L ‐arginine. Elevation of external Ca 2+ content significantly reduced the inhibitions due to Cd 2+ on the EFS‐induced relaxation and on the EFS‐evoked guanethidine‐sensitive contraction. In the Ca 2+ ‐omitted medium, EFS‐induced relaxation disappeared, while acetylcholine‐elicited relaxation resisted. Verapamil was ineffective on the relaxation produced by EFS or acetylcholine. However, it significantly diminished phenylephrine‐induced contractions. These findings suggest that unlike other cations at the concentrations used in the present study, Cd 2+ may have an effect on an external Ca 2+ ‐dependent mechanism at the neuronal level, and this effect may be responsible for its acute inhibitory action on the neurogenic relaxation in the mouse corpus cavernosum.