EFFECTS OF MELATONIN TREATMENT ON INFLAMMATORY MARKERS AND PITUITARY DYSFUNCTION IN INSULIN RESISTANT RATS

JUAN SALVADOR CALANNI; MARÍA ELISA MERCAU; MORENA WISZNIEWSKI; MARCOS ARANDA; SILVIA SÁNCHEZ PUCH; CAROLINA VECINO; ESTEBAN MARTÍN REPETTO; CORA BEATRIZ CYMERYNG

Ciudad Autónoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIC

Excessive consumption of diets with high sugar content has beenassociated with an increased incidence of insulin resistance andobesity. Several reports have shown a concomitant dysfunction ofthe hypothalamus pituitaryadrenal(HPA) axis in these patients.We have previously reported that rats fed a sucrose richdiet (SRD,30% sucrose in the drinking water) for 7 weeks show a significantdecrease in insulin sensitivity. Analysis of HPA axis activity after 3weeks of treatment, when changes in insulin sensitivity were still notevident, showed augmented levels of circulating ACTH and a higherpituitary expression of POMC that was accompanied by an increasein oxidative stress parameters.Present experiments were designed to analyze the involvementof inflammation-related effects on the observed pituitary dysfunction.Animals were randomly distributed in 4 groups: 1) Control, 2)SRD, 3) Mel and 4) SRD + Mel. In groups 3 and 4, subcutaneousmelatonin implants (10mg) were surgically implanted. Animals weresacrificed after 3 weeks and pituitary glands were processed to obtainprotein and RNA.Results showed an increase in mRNA levels of TNFα (p