Acute and chronic exercise modulates the expression of MOR opioid receptors in the hippocampal formation of rats.
Exercise stimulates the release of beta-endorphin and other endogenous opioid peptides that are believed to be responsible for changes in mood, perception of pain and also performance. Although the vast majority of literature data support the role of physical exercise in increasing beta-endorphin levels, indirect measures such as increased endorphin levels in peripheral blood do not reflect opioid levels in the central nervous system. The purpose of the present study was to verify whether acute and chronic exercise using both voluntary and forced exercise procedures could modify the expression of μ-opioid receptors (MOR) in rat hippocampal formation. Immunoblotting analysis showed significantly enhanced MOR expression in the hippocampal formation in the acute (forced and voluntary) exercise groups when compared to the control group. Conversely, a significant reduction of MOR expression was noted in the chronic forced and chronic voluntary exercise groups compared to the acute forced and voluntary groups respectively. MOR expression was not significantly different in rats trained using both acute or chronic exercise. Immunohistochemistry analysis showed a higher number of MOR-positive cells for acute forced and voluntary exercise groups in the CA1, CA3, hilus and dentate gyrus regions compared to the control group. Our findings indicate that acute and chronic exercise modulates MOR expression in the hippocampal formation of rats.
de Oliveira
Mônica Sílvia Rodrigues
MS
Universidade de Mogi das Cruzes, São Paulo, Brazil.
da Silva Fernandes
Maria José
MJ
Scorza
Fulvio Alexandre
FA
Persike
Danielle Suzete
DS
Scorza
Carla Alessandra
CA
da Ponte
Jaqueline Botelho
JB
de Albuquerque
Marly
M
Cavalheiro
Esper Abrão
EA
Arida
Ricardo Mario
RM
D000328:Adult; D000818:Animals; D006624:Hippocampus / Q000033:anatomy & histology / Q000378:metabolism*; D006801:Humans; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D012420:Running
D017450:Receptors, Opioid, mu