NO donor SIN-1 potentiates monosynaptic reflexes in the cat spinal cord.
The effect produced by the nitric oxide donor SIN-1 on monosynaptic reflexes was examined. Experiments were performed on anesthetized, paralyzed and spinalized cats. Lumbar monosynaptic reflexes were produced by stimulation of Ia afferents. I.v. application of SIN-1 (500 microg/kg) produced a mean marked potentiation of 704% of pre-drug control (100%) in the amplitude of monosynaptic reflexes. In addition, in other experiments a concentration-dependent effect on the amplitude of monosynaptic reflexes was observed after microinjections of SIN-1 into the ventral horn (1 microl; 10(-12) - 10(-3) M), with a mean facilitatory effect of 355%. In both cases, the potentiation was reversible 45 min after i.v. or local application of SIN-1. These results provide the first evidence that monosynaptic reflexes can be potentiated by nitric oxide.
Manjarrez
E
E
Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 sur 6301, Col. San Manuel, Apartado Postal 406., Puebla, Pue. CP 72570, México.
Rocha
T
T
Rojas-Piloni
G
G
Méndez
I
I
Vélez
D
D
Flores
A
A
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004594:Electrophysiology; D007275:Injections, Intravenous; D008845:Microinjections; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D012023:Reflex, Monosynaptic / Q000187:drug effects* / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects* / Q000502:physiology; D013569:Synapses / Q000187:drug effects* / Q000502:physiology
D020030:Nitric Oxide Donors; C002385:linsidomine; D008981:Molsidomine