The effect of captopril on the membrane properties of central neurons in-vitro.
Captopril, a potent antihypertensive that acts via inhibition of angiotensin converting enzyme also has apparent central actions. Its effects on membrane properties on particular central neurons in-vitro has therefore been investigated. In the substantia nigra, where there is a high concentration of angiotensin converting enzyme, captopril caused a dose-dependent depolarization without any apparent change in conductance, but possibly requiring the integrity of the dendritic arbour. A similar effect occurred when captopril was applied to neurons in either the thalamus or hippocampus, where levels of angiotensin converting enzyme are relatively low. Further studies with homologues of captopril revealed that the -SH group on the molecule was a prerequisite of the effect observed. It is concluded that the -SH group on the captopril molecule has an electrogenic effect on diverse central neurons, independent of inhibition of angiotensin converting enzyme, but preferentially manifest at the level of the dendrite.
Robinson
E L
EL
University Department of Pharmacology, Oxford, UK.
Greenfield
S A
SA
D000818:Animals; D002216:Captopril / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects; D005260:Female; D006168:Guinea Pigs; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure*; D010477:Perfusion; D013378:Substantia Nigra / Q000166:cytology / Q000187:drug effects; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D013788:Thalamus / Q000166:cytology / Q000187:drug effects
D013757:Tetraethylammonium Compounds; D002216:Captopril