RESUMEN
Amikacin sulphate (30 mg kg(-1)) administered either intraperitoneally (i.p.) or subcutaneously (s.c.) produced antinociceptive effect in BALB/c mice in the acetic acid writhing test which is employed as an inflammatory pain model. The lack of difference between two routes with regard to antinociceptive potency was taken as evidence for the absence of a local effect. Amikacin sulphate-induced antinociception seems unlikely to be due to non-specific behaviour alteration, since this drug, at a dose range of 15-100 mg kg(-1)did not affect motor coordination of mice in rot-a-rod test. Morphine (1 mg kg(-1)) also caused antinociception when administered i.p. or s.c. but the effect was greater with the latter route. At the i.p. site; the concurrent use of amikacin and morphine produced more remarkable antinociception compared to their individual usages. Besides, naloxone (2 mg kg(-1)) significantly decreased antinociceptive effect of amikacin but itself also exerted antinociception. At present, we have no plausible explanation for these findings at the i.p. site.
Asunto(s)
Amicacina/uso terapéutico , Analgésicos/uso terapéutico , Morfina/uso terapéutico , Naloxona/uso terapéutico , Dolor/prevención & control , Acetatos , Animales , Modelos Animales de Enfermedad , Interacciones Farmacológicas , Inyecciones Intraperitoneales , Inyecciones Subcutáneas , Ratones , Ratones Endogámicos BALB C , Dolor/inducido químicamente , Umbral del DolorAsunto(s)
Aminoácidos/metabolismo , Apomorfina/farmacología , Aminas Biogénicas/metabolismo , Encéfalo/metabolismo , Clorpromazina/farmacología , Glicina/farmacología , Animales , Unión Competitiva , Encéfalo/efectos de los fármacos , Dopamina/metabolismo , Levodopa/farmacología , Ratas , Ratas Endogámicas , Factores de TiempoRESUMEN
The effects of stress and lithium on brain free amino acid levels in rats were investigated. Stress caused a significant decrease in the brain levels of alanine, ammonia, arginine, isoleucine, lysine and phenylalanine. Lithium by itself induced a significant increase in the brain levels of arginine and threonine, and a significant decrease in those of alanine, ammonia, aspartic acid, glutamic acid, glycine, lysine, phenylalanine and tyrosine. Lithium and stress together significantly decreased brain levels of alanine, arginine, aspartic acid, glycine, isoleucine, leucine, lysine, phenylalanine and tyrosine, and significantly increased that of serine.
Asunto(s)
Aminoácidos/metabolismo , Química Encefálica/efectos de los fármacos , Litio/farmacología , Estrés Fisiológico/metabolismo , Animales , RatasRESUMEN
The effect of lithium on the brain levels of monoamines was examined in stress-exposed rats. It was found that stress lowered brain levels of noradrenaline and serotonin and had no effect on the brain level of dopamine. Lithium, alone, caused a decrease in brain levels of noradrenaline and dopamine, but not in serotonin. Nevertheless, the diminished level of serotonin in stress-exposed rats increased by lithium treatment. It may be possible to make a correlation between the later finding with the inhibitory effect of lithium on aggression in human beings and animals.