ABSTRACT
Aims: The objective was to evaluate the single exposure of general anesthetics with or without a surgical procedure at postnatal day 14 (P14) on nociceptive behavioral responses. Furthermore, we evaluated ectonucleotidase activities at P14 and P30. Place of Study: All experiments were performed at the Animal Experimentation Unit of Hospital de Clínicas de Porto Alegre. The Institutional Committee approved the experimental protocol f (GPPG-HCPA protocol No: 08149). Methodology: Fourteen-day-old male Wistar rats were divided into two experimental designs (ED): the 1st ED – control (C), isoflurane (ISO), isoflurane/surgery (ISO-SUR) and the 2nd ED – control (C), fentanyl/S(+)-ketamine (FK) and fentanyl/S(+)- ketamine/surgery (FK-SUR). Nociceptive responses were evaluated using the formalin and tail-flick tests, and the ectonucleotidase activities were evaluated by spinal cord synaptosome. All assessments were performed at P14 and P30. Results: The FK and FK-SUR groups displayed an increased latency at P30. For the ectonucleotidase activity analysis, the following results were observed: (a) in the 1st ED, the ISO group displayed a reduction in ATPase and ADPase, and both ISO and ISOSUR displayed a reduction in AMPase activity at P14; (b) in the 2nd ED, the FK group displayed an increase in AMPase activity at P14 and increased ATPase activity at P30, and both FK and FK-SUR exhibited an increase in AMPase activity at P30. Conclusion: Our results indicate that single administration of general anesthetics at P14 is able to promote changes in the nociceptive response in the intermediate-term, and in the ectonucleotidase activities in the short- and medium-terms.
ABSTRACT
Objective: Adenine nucleotides and adenosine have many important functions in the physiological and pathological conditions. The measurement of these nucleotides in serum may be an auxiliary tool in the identification of cellular damage in many pathological conditions. The aim of this study is to examine the effect of chemotherapy treatment on nucleotide hydrolysis in the serum of rats following glioma implantation. Methods: C6 glioma cells were injected in the right striatum of 60 day-old Wistar rats, and 20 days after the induction of gliomas, blood serum samples were prepared for measurement of ATP and AMP hydrolysis. Results: The pathological analysis showed that the malignant gliomas induced by C6 injection and treated with temozolomide exhibited a reduction in malignant characteristics. The results demonstrated that the rats that underwent temozolomide treatment had a significant decrease (p<0.05) in blood serum hydrolysis of ATP and AMP when compared with the glioma group. None of the animals included in this study presented significant alterations in the activities of the serum enzymes alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase. Conclusion: The decrease in the enzymatic hydrolysis of the ATP and AMP is probably related to the diminished malignant characteristics caused by temozolomide treatment on the gliomas in vivo.