IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effect of melatonin suppression by SCGx in the rat metabolism
Autor/es:
PLANO SA; MUÑOZ EM
Lugar:
Tunuyan
Reunión:
Congreso; XII Latin American Symposium on Chronobiology; 2013
Resumen:
Circadian rhythms are endogenous variations in nearly all physiological functions with a periodicity of approx 24 hours. These rhythms are synchronized to the environment by photic and nonphotic stimuli. Melatonin is synthesized in a circadian fashion by the pineal gland. Under SCN control, AA-NAT is activated at night by NE released from the superior cervical ganglia (SCG). Shift work is a working condition leading to alterations in 6-sulfatoxymelatonin levels. Shift workers are predisposed to cognitive impairment, cardiac/metabolic disorders with increased body mass index and obesity, glucose intolerance and higher risk of Type 2 diabetes mellitus. In vitro melatonin was reported to stimulate glucose uptake by adipocytes and muscle cells and to stimulate leptin expression. Moreover, rats submitted to pinealectomy become glucose intolerant and exhibit increased hepatic glucose production. The bilateral SCG removal (SCGx) has proved to be a solid and reliable procedure to completely prevent nocturnal AA-NAT increase, irreversibly suppressing melatonin rhythm. In the present work we studied the role of melatonin in the rat metabolism by chronic SCGx. We found a significant difference between SCGx and sham rats in metabolic parameters measured from youth to adulthood, proving that melatonin plays a key role in metabolism and that SCGx is a valid model without brain-invasive surgery.