Influences of sodium on the contraction induced by oxytocin in rat testicular capsule.
1. The effect of tetrodotoxin (5 microM), monensin (10 microM) and the replacement of Na+ by choline (choline medium) on the contractions of the rat testicular capsule induced by oxytocin (50 and 200 nM) have been studied. 2. The sodium channel blocker tetrodotoxin did not modify the oxytocin contraction. 3. The sodium ionophore monensin produces contraction of rat testicular capsule and reduces the oxytocin-induced contraction. The monensin contraction is inhibited by amiloride (0.1 mM). 4. Replacement of Na+ by choline increases the contraction induced by oxytocin and KCl (60 mM) but inhibits that induced by noradrenaline (3 microM). 5. The increase of contraction due to oxytocin in choline medium is inhibited by amiloride (50 microM and 1 mM) and when calcium is suppressed of the incubation medium.
Departamento de Medicina, Facultad de Medicina, Universidad de Oviedo, Spain.
M
M
Sanchez
F
F
Andrés-Trelles
A
A
Hidalgo
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002794:Choline / Q000494:pharmacology; D066298:In Vitro Techniques; D007474:Ion Exchange; D008297:Male; D008985:Monensin / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D010121:Oxytocin / Q000494:pharmacology*; D051381:Rats; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology*; D013737:Testis / Q000187:drug effects* / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology
D013779:Tetrodotoxin; D010121:Oxytocin; D008985:Monensin; D012964:Sodium; D002794:Choline; D002118:Calcium