scholarly journals INHIBITION OF K-INDUCED TONIC CONTRACTION IN VAS DEFERENS OF GUINEA PIG BY CHLORPROMAZINE AND ITS FREE RADICAL

1974 ◽  
Vol 24 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Shigeru YAMABE ◽  
Aritomo SUZUKI ◽  
Hiroshi MATSUMOTO
Keyword(s):  
Free Radical ◽  
Guinea Pig ◽  
Vas Deferens ◽  
Tonic Contraction

Contribution of Na+ and membrane depolarization to contraction induced by adrenaline in the guinea pig vas deferens

1986 ◽  
Vol 64 (6) ◽  
pp. 720-723 ◽  
Author(s):  
Sadaharu Usune ◽  
Takeshi Katsuragi ◽  
Yasuzi Sakamoto ◽  
Tatsuo Furukawa
Keyword(s):  
Guinea Pig ◽  
Vas Deferens ◽  
Rhythmic Activity ◽  
Membrane Depolarization ◽  
Tonic Contraction ◽  
Rhythmic Contraction ◽  
High K ◽  
Membrane Bound ◽  
Small Contraction ◽  
Rhythmic Contractions

The contribution of Na+ and membrane depolarization to biphasic contractions induced by adrenaline were investigated in the smooth muscle of guinea pig vas deferens. Adrenaline (5 × 10−6 M) produced an initial small contraction (first contraction) followed by a large tonic contraction (second contraction) with subsequent rhythmic activity. The entire response to adrenaline was largely inhibited by phentolamine (5 × 10−6 M). By adding an appropriate concentration of Mn2+ (2 × 10−4 M) or nifedipine (3 × 10−7 M), a Ca2+ blocker, the second contraction was strongly reduced, accompanied by abolishment of the rhythmic contraction, whereas the first contraction was virtually unaffected. However, the first contraction was markedly suppressed by a higher concentration of Mn2+. All contractions produced by adrenaline were greatly reduced in Ca2+-free solution containing 0.5 mM EGTA. By lowering external Na+ concentration, the first contraction was markedly increased without greatly affecting the second contraction. By exposure to Na+-free isotonic high K+ solution, which elicited a greater depolarization of the membrane, the first contraction produced by adrenaline was also greatly potentiated, while the second and rhythmic contractions were eliminated. These results suggest that the adrenaline-evoked first contraction may be due to an influx of membrane bound Ca2+ which is independent of membrane depolarization, while the second (rhythmic) contraction is due to an influx of extracellular Ca2+ which is dependent upon depolarization.

scholarly journals Inhibitory effect of beauvericin on a high K+-induced tonic contraction in guinea-pig taenia coli.

1987 ◽  
Vol 45 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Shinjiro NAKAJYO ◽  
Kiyomi MATSUOKA ◽  
Tomohiro KITAYAMA ◽  
Yutaka YAMAMURA ◽  
Kazumasa SHIMIZU ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Inhibitory Effect ◽  
Tonic Contraction ◽  
Taenia Coli ◽  
High K

Opioid agonist affinity in the guinea-pig ileum and mouse vas deferens

1990 ◽  
Vol 179 (1-2) ◽  
pp. 129-139 ◽  
Author(s):  
Frank Porreca ◽  
Diane LoPresti ◽  
Susan J. Ward
Keyword(s):  
Guinea Pig ◽  
Vas Deferens ◽  
Guinea Pig Ileum ◽  
Opioid Agonist ◽  
Mouse Vas Deferens ◽  
Agonist Affinity
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