Hypo-algesia caused by acute administration of sweet substance in rodent- and human-based pain models
Daoud Hibrahim Elias-Filho
Laboratório de Neuroanatomia & Neuropsicobiologia, Departamento de Farmacologia, FMRP-USP, Av. dos Bandeirantes, 3900, Ribeirão Preto (SP), 14049-900, Brasil
Abstract:
There is evidence that sweetened substances cause antinociception in young rats. The aim of the present work is to compare the effect of acute intake of sucrose solution on nociceptive thresholds (NT) in adult rats and humans. Male Wistar rats (n=8 per group), and male and females (n=6-7) volunteers were submitted to the experiment. All subjects were informed, and requested for consent. After the baseline, oral intake of 0.5mL (in rodents) or 5.0mL (in humans) of spring water or sucrose at 25, 50, 150 and 250g/L, were done before the tail-flick test (in rodents) or hot stimuli applied on the ventral part of the left forearm (in humans), and the pain threshold was recorded from 5-5min, during 30 min. NT increased in rats after the treatment with sucrose solution at 50g/L, during 5min, 150g/L and 250g/L, during 20min, in both cases. Major doses of acute sucrose intake also increased NT from 5min to 30min in humans. In addition, the aversion to painful stimuli was lower after the pretreatment with sucrose at 150g/L and 250g/L. Sucrose solutions seem to reduce pain-related responses in both adult rodents and humans, and it may be a safe and useful analgesic for minor surgical interventions.
Supported by FAPESP, CNPq and FAEPA.
