Activation of nigral M1 and M2 muscarinic receptors produces opposing effects on striatal 3,4-dihydroxyphenylacetic acid measured by in vivo voltammetry.
3,4-dihydroxyphenylacetic acid (DOPAC) was measured by differential pulse voltammetry in the neostriatum of anesthetized rats. DL-Muscarine (2.9 nmol) applied into the substantia nigra pars compacta, increased DOPAC concentration in the ipsilateral neostriatum. This effect was blocked by pirenzepine (2.8 nmol), and potentiated by AF-DX 116 (2.8 nmol). These results indicate the existence of two types of muscarinic receptors on dopaminergic neurons, whose activation produces opposing effects on dopamine metabolism in neostriatum.
Góngora-Alfaro
J L
JL
Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional de México, D.F., Mexico.
Hernández-López
S
S
Martínez-Fong
D
D
Brassart
J L
JL
Aceves
J
J
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004563:Electrochemistry / Q000379:methods; D007839:Functional Laterality; D008297:Male; D009116:Muscarine / Q000008:administration & dosage / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology; D010890:Pirenzepine / Q000031:analogs & derivatives / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*; D013238:Stereotaxic Techniques; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology*
D010276:Parasympatholytics; D011976:Receptors, Muscarinic; D015102:3,4-Dihydroxyphenylacetic Acid; D010890:Pirenzepine; D009116:Muscarine; C048593:otenzepad