Enhancement of spinal monosynaptic reflexes with phenylethylamine and related drugs through descending noradrenergic neurons.
The effects of phenylethylamine (PEA) and related drugs, such as methamphetamine, phenelzine, methylphenidate, nomifensine and mazindol on the spinal monosynaptic reflex (MSR) were investigated in rats treated with 6-hydroxydopamine (6-OHDA) or 5,6-dihydroxytryptamine (5,6-DHT). PEA (1 x 10(-5) mol/kg, i.v.) increased the amplitude of MSR in control rats, but decreased the amplitude in rats treated with 6-OHDA. Although PEA-related drugs increased the amplitude of MSR, they did not change the MSR amplitude in 6-OHDA-treated rats. In 5,6-DHT-treated rats, PEA-related drugs increased the amplitude of MSR, whereas PEA produced a decrease. These results support our previous suggestion that the enhancement of MSR by these drugs might be mediated through release of noradrenaline or inhibition of noradrenaline uptake at the noradrenergic synapses.
Hasebe
Y
Y
Department of Toxicology and Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Ono
H
H
Fukuda
H
H
Ohta
S
S
Hirobe
M
M
D015115:5,6-Dihydroxytryptamine / Q000494:pharmacology; D000320:Adrenergic Fibers / Q000187:drug effects*; D000818:Animals; D006892:Hydroxydopamines / Q000494:pharmacology; D008297:Male; D016627:Oxidopamine; D010627:Phenethylamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012023:Reflex, Monosynaptic / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects*
D006892:Hydroxydopamines; D010627:Phenethylamines; D016627:Oxidopamine; D015115:5,6-Dihydroxytryptamine