Inalação de crack aumenta a susceptibilidade a crises epilépticas via redução da atividade da acetilcolinesterase

Abstract

In Brazil, there have been reports in the literature on the use of crack cocaine since 1990. In the last decades its consumption has increased due to the high power of addiction and low cost, causing a serious public health problem. Crack cocaine is a psychostimulant drug that can cause neurological, biochemical and behavioral changes. Animal studies have shown that dopaminergic, glutamatergic and cholinergic pathways may play a role in the neurotoxicity and behavior induced by the inhalation of crack cocaine and its metabolites. Thus, the present study aimed to evaluate latency, frequency, duration and severity for limbic seizures and wet dog shake expression (WDS) in rats, 120 minutes after microinjection of low dose pilocarpine (PILO) followed by exposure to crack cocaine pyrolysis products, as well as to measure salivary flow stimulated by administration of PILO (2 mg / kg) 0h, 24h and 15 days after exposure to crack. In addition, the activity of acetylcholinesterase (AChE) in the hippocampus was analyzed after 10 and 60 minutes of microinjection of a low dose of PILO followed by exposure to crack cocaine. Our results show a decrease in latency for seizures when animals were treated with PILO and later exposed to crack cocaine (PILO + CRACK). The frequency, duration and severity of epileptic seizures increased in the PILO + CRACK group in relation to the groups exposed only to PILO or crack. As for the WDS expression, there was an increase in the PILO + CRACK and PILO groups when compared to the CRACK. In addition, the weight of the parotid and submandibular glands did not change during exposure (0h) and 24h and 14 days after exposure to crack, although an expressive increase in salivary flow was observed in animals exposed 14 days to inhalation of crack. The activity of AChE, in the time of 10 min, was increased in the CRACK group when compared to NAIVE and the inhibition of hippocampal AChE was observed 60 min after exposure to crack cocaine in the groups CRACK AND PILO + CRACK when compared to the animals NAIVE. Taken together, these findings suggest that a low dose of PILO followed by crack cocaine inhalation increases the excitability of nerve tissue to the extent of promoting lowering of the threshold for epileptic seizures, as well as increased salivary flow, presumably through inhibition of AChE.