Prolonged physical training decreases mRNA levels of glucocorticoid receptor and inflammatory genes.
OBJECTIVE
Prolonged physical exercise induces adaptive alterations in the hypothalamic-pituitary axis, increasing cortisol metabolism, and reducing cortisol synthesis and glucocorticoid sensitivity. The mechanisms responsible for this relative glucocorticoid resistance remain unknown but may involve expression of genes encoding glucocorticoid receptor (GR) and/or inflammatory molecules of nuclear factor kappa B1 (NFkB1) signaling pathway and cytokines. This study aimed to determine the impact of prolonged physical training on the expression of genes involved in glucocorticoid action and inflammatory response.


METHODS
Normal sedentary male cadets of the Brazilian Air Force Academy were submitted to 6 weeks of standardized physical training. Eighteen of 29 initially selected cadets were able to fully complete the training program. Fasting glucose, insulin and cortisol levels, cytokine concentration and the expression of genes encoding GR, NFkB1, inhibitor of NFkB1 and IkB kinase A were determined before and after the training period.


RESULTS
Prolonged physical exercise reduced the basal cortisol levels and the percent cortisol reduction after dexamethasone. These findings were associated with a significant reduction in the mRNA levels of GR (6.3%), NFkB1 (63%), inhibitor of NFkB1 (25%) and IkB kinase A (46%) with concomitant reduction in cytokine concentrations (ELISA).


CONCLUSIONS
Prolonged physical training decreases the glucocorticoid sensitivity and the mRNA levels of the GR gene combined with decreased mRNA of genes related to the NFkB pathway.
Sousa e Silva
Tatiane
T
Molecular Medicine Laboratory, Physiology Department, Santa Casa de São Paulo, Faculty of Medical Sciences, São Paulo, Brazil.
Longui
Carlos Alberto
CA
Rocha
Mylene Neves
MN
Faria
Claudia Dutra Costantin
CD
Melo
Murilo Rezende
MR
Faria
Thelma Gomes
TG
de Souza
Julio Antonio
JA
Rizzo
Luiz Vicente
LV
D000293:Adolescent; D001786:Blood Glucose / Q000502:physiology; D001823:Body Composition / Q000502:physiology; D016207:Cytokines / Q000235:genetics / Q000502:physiology; D005938:Glucocorticoids / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000502:physiology; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D051550:I-kappa B Kinase / Q000235:genetics / Q000502:physiology; D007328:Insulin / Q000097:blood / Q000502:physiology; D008297:Male; D016328:NF-kappa B / Q000235:genetics / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D010913:Pituitary-Adrenal System / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D055815:Young Adult
D001786:Blood Glucose; D016207:Cytokines; D005938:Glucocorticoids; D007328:Insulin; D016328:NF-kappa B; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D051550:I-kappa B Kinase; D006854:Hydrocortisone