Role of periaqueductal gray MU and Kappa opioid receptors in stress-induced fever

• Grant number: 13/02813-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): May 01, 2013
• Effective date (End): February 28, 2014
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Kênia Cardoso Bícego
• Grantee: Caroline Cristina Silva
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The endogenous opioids are involved in analgesia and physiological responses to various stressful stimuli such as infection, psychological stress, and also body temperature (Tc) regulation. These mediators induce an increase or decrease of Tc depending on the receptor, MU, and kappa, which is activated. There is evidence that mu receptors in the hypothalamus are involved in endotoxin-induced fever and kappa receptors in the opposite response, hypoxia-induced regulated Tb reduction. Furthermore, it is known that febrile responses induced by both bacterial endotoxin and psychological stress present several similarities in their mechanisms of development. The periaqueductal gray (PAG) seems to be a possible site in the central nervous system involved in the febrile responses to stress because it is involved in defense responses and presents both mu and kappa receptors. Thus, the objective of the present study is to verify the role of mu and kappa opioid receptors in the PAG of rats in restraint-induced fever. To this end, four protocols will be performed to verify: 1) the effect of intra-PAG microinjection of kappa opioid receptors selective antagonist, nor-BNI, in euthermic rats; 2) effect of intra-PAG microinjection of nor-BNI in rats during restraint stress, 3) effect of intra-PAG microinjection of MU-opioid receptors selective antagonist, CTAP, in euthermic rats and 4) the effect of intra-PAG microinjection of CTAP in rats during restraint stress. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CRISTINA-SILVA, CAROLINE; MARTINS, VICTOR; GARGAGLIONI, LUCIANE H.; BICEGO, KENIA C.. Mu and kappa opioid receptors of the periaqueductal gray stimulate and inhibit thermogenesis, respectively, during psychological stress in rats. PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, v. 469, n. 9, p. 1151-1161, SEP 2017. (15/04849-6, 13/02813-9)