Atividade analgésica em camundongos Swiss submetidos a diferentes doses de cloreto de magnésio (MgCl2) associado ou não a paracetamol e clonazepam

Abstract

The pain perception represents an important adapting mechanism based on the nociceptive system function, which depends on the excitability of the nervous system, thus, searching new methods of control for the excitability in the nociceptive system is very important for the human analgesia. Objective: To determine the excitation threshold of nociceptive system in mice treated with different doses of magnesium chloride, associated or not with paracetamol and clonazepam. Material and Methods: Swiss mice were treated with magnesium chloride, paracetamol and clonazepam. The excitation threshold was determined by the “hot plate” test. Result and Discussion: Magnesium chloride (130mgKg-1) showed a synergistic action with Paracetamol (12.5mgKg-1) probably due to a low excitability in the nociceptive system and depolarization in the endogenous analgesic system. The clonazepam (0.066mgKg-1) seems to block an analgesic action of the magnesium chloride in the endogenous analgesic system by the neural hyperpolarization, due to the chloride influx. Conclusions: Magnesium chloride (130mgKg-1) strengthened the analgesic action of paracetamol. The clonazepam seems to have blocked an analgesic action of magnesium chloride probably in the endogenous analgesic system.