8-Phenyltheophylline reverses the antinociceptive action of morphine in the periaqueductal gray.

Neuropharmacology (1991-08-01)
J Sawynok, M J Espey, A Reid
RESUMO

Morphine was injected into the periaqueductal gray region of the rat and 8-phenyltheophylline, an adenosine receptor antagonist, was injected intrathecally 15 or 30 min later, to determine whether supraspinally-administered morphine activated descending mechanisms to release adenosine (or a nucleotide which is metabolized to adenosine) from the spinal cord. 8-Phenyltheophylline (10 micrograms) reversed the antinociceptive action of morphine in the hot plate but not the tail-flick test. A combination of methysergide/phentolamine (15 micrograms each) reversed the action of morphine in both tests. 8-Phenyltheophylline retained the ability to reverse the action of morphine in the hot plate test in rats pretreated with 6-hydroxydopamine (to induce degeneration of descending noradrenergic pathways) but reversal was no longer observed in rats pretreated with 5,7-dihydroxytryptamine (after pretreatment with desipramine, to induce degeneration of descending serotonergic pathways). These results indicate that a component of the supraspinal antinociceptive action of morphine is due to release of adenosine or nucleotide, within the spinal cord and this release is dependent on intact serotonergic pathways.

MATERIAIS
Número do produto
Marca
Descrição do produto

Sigma-Aldrich
1,3-Dimethyl-8-phenylxanthine, crystalline

Redes sociais

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

Merck

Pesquisa. Desenvolvimento. Produção.

Somos um fornecedor global líder para o setor de ciências biológicas, com soluções e serviços para pesquisa, desenvolvimento e produção de biotecnologia, além de produção e desenvolvimento de terapias farmacológicas com medicamentos.

© 2021 Merck KGaA, Darmstadt, Alemanha e/ou suas filiais. Todos os direitos reservados.

A reprodução não autorizada de quaisquer materiais deste site é estritamente proibida.