Effect of tetrahydroisoquinoline (TIQ), one of endogenous substances inducing parkinsonism, on isolated rat vas deferens.
1. The effect of tetrahydroisoquinoline (TIQ) was examined on isolated rat vas deferens. 2. TIQ shifted the concentration-response curve for norepinephrine towards lower concentrations: the pD2-value of norepinephrine in the presence of TIQ was significantly greater than in its absence. 3. Tyramine-induced contraction in the presence of TIQ decreased by a significant 35% more than in the absence of TIQ. 4. These results indicate that the pharmacological effect of TIQ is due to the inhibition of the neuronal uptake of catecholamines.
Koike
K
K
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.
Takayanagi
I
I
Wani
S
S
Yanagita
T
T
Ohta
S
S
Hirobe
M
M
D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects; D010302:Parkinson Disease, Secondary / Q000139:chemically induced* / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D044005:Tetrahydroisoquinolines; D014649:Vas Deferens / Q000187:drug effects
D002395:Catecholamines; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; C014843:1,2,3,4-tetrahydroisoquinoline