These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: [Effects of analgesic-antipyretics on the spinal reflex potentials in cats: an analysis of the excitatory action of aminopyrine]. Author: Hara Y, Murayama S. Journal: Nihon Yakurigaku Zasshi; 1992 Nov; 100(5):383-90. PubMed ID: 1464397. Abstract: The effects of some analgesic-antipyretics on the spinal reflex potentials were studied in spinal cats. Aminopyrine at 25-100 mg/kg, i.v. produced a marked increase in mono- and poly-synaptic reflex potentials (MSR and PSR), and a decrease in dorsal root reflex potentials (DRR) in a dose-dependent manner. The amplitude of DRR decreased by aminopyrine was reversed by diazepam at 0.2 mg/kg, i.v.; however, the increased amplitudes of MSR and PSR were not affected by diazepam. Pretreatment of semicarbazide at 200 mg/kg, i.v. did not influence the increasing effect of aminopyrine on MSR and PSR. DL-5-Hydroxytryptophan produced facilitation of the MSR and PSR. In DL-5-hydroxytryptophan-treated cats, the amplitude of MSR was further increased by aminopyrine. Methysergide at 1 mg/kg, i.v. antagonized this increasing effect of aminopyrine on MSR and PSR. These observations suggest that the excitatory action of aminopyrine may be partly related to 5-hydroxytryptamine and not connected to the GABAergic mechanism. Other pyrazolone derivatives were also studied. Isopropylantipyrine at 50 mg/kg, i.v. produced increases in MSR and PSR. Intravenous sulpyrine at 500 mg/kg, antipyrine at 50 mg/kg or 4-aminoantipyrine at 50 mg/kg did not affect the reflex potentials. The non-pyrazolones, acetaminophen and indomethacin, did not increase the MSR and PSR. These results suggest that the N-dimethyl or isopropyl residue at the 4 position of the pyrazolone structure plays an important role in the excitatory action of analgesic-antipyretics in cat spinal cord.[Abstract] [Full Text] [Related] [New Search]