Comparison of displacemental potencies of terazosin enantiomers for alpha 1-adrenoceptor subtypes.
The present study was designed to assess displacemental potencies of terazosin and its isomers for alpha 1 High and alpha 1 Low adrenoceptor subtypes in rat brain, heart, bovine prostate and canine aorta using a radioligand binding assay method. Although no significant difference in pKi values of each terazosin isomer for alpha 1 High in canine aorta and rat brain were observed, the displacemental potency of (S-)terazosin for those in rat heart and bovine prostate was stronger than that of (R+)isomer (p < 0.01). On the other hand, only in alpha 1 Low subtypes of bovine prostate was stronger displacemental potency of (S-)terazosin than (R+)isomer (p < 0.05) observed. Thus, these results imply that there is a different affinity between (S-)terazosin and (R+)isomer on the alpha 1 High in bovine prostate and rat heart and alpha 1 Low in bovine prostate.
Maruyama
K
K
Department of Pharmacology, Niigata College of Pharmacy, Japan.
Ohkura
N
N
Yagi
Y
Y
Nagatomo
T
T
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D001667:Binding, Competitive / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002417:Cattle; D004285:Dogs; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000378:metabolism; D011224:Prazosin / Q000031:analogs & derivatives* / Q000494:pharmacology; D011467:Prostate / Q000187:drug effects / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects*; D013237:Stereoisomerism
D018340:Receptors, Adrenergic, alpha-1; C041226:Terazosin; D011224:Prazosin