Estudio de marcadores biológicos de estrés en la glándula tiroides y en el timo de rata en un modelo experimental de radiación subtérmico a 2,45 GHz

Introducción: En el campo de la Medicina Física y Rehabilitación se utilizan las microondas por los efectos terapéuticos causados por el calentamiento en los tejidos. Se desconocen, sin embargo, cuales son los efectos subtérmicos tisulares de las microondas. Esta tesis es un estudio experimental de marcadores biológicos obtenidos en las glándulas tiroides y timos de las ratas después la exposición subtérmica a 2,45 GHz. Objetivos: a) La obtención de un modelo experimental de radiación subtérmico en ratas Sprague-Dawley de exposición localizada con una sistema de radiación controlada a 2,45 GHz. b) Cálculo dosimétrico y estudio de marcadores biológicos tisulares y morfológicos en las glándula tiroides y timos de ratas que permitan determinar niveles de estrés celular después de la radiación de los animales

Efecto de la radiofrecuencia aguda y repetida a 2,45 GHz en la morfología de la glándula tiroides de rata

Non-ionizing radiation at 2.45 GHz may modify the morphology and expression of genes that codify heat shock proteins (HSP) in the thyroid gland. Fifty six rats were individually exposed once or repeatedly (ten times in 2 weeks) for 30 min to 2.45 GHz radiation in a Gigahertz transverse electromagnetic (GTEM) cell at different levels of non-thermal specific absorption rate (SAR), which was calculated using the finite difference time domain (FDTD) technique. Using the immunohistochemistry technique, we studied the expression of HSP-90 protein and morphological changes in tissues thyroid gland. Ninety minutes after the radiation of the central and peripheral follicles increased in size while the peripheral wall thickness suffered a decrease in size with the highest SAR exposure. Twenty four hours after radiation central and peripheral follicles decrease in size with the SAR of 0.4 ± 12×10-3. Likewise with repeated exposure showed a decrease in the size of the follicles (peripheral and central). Morphological changes in the thyroid gland after radiation indicate acute or repeated stress adaptation in thyroid tissue in the hypothalamic-thyroi

La radiofrecuencia aguda y repetida a 2,45 GHz provoca incremento de la expresión de C-FOS en el hipotálamo

Non-ionizing radiation at 2.45 GHz may modify the morphology and expression of genes that codify heat shock proteins (HSP) in the thyroid gland. Fifty six rats were individually exposed once or repeatedly (ten times in 2 weeks) for 30 min to 2.45 GHz radiation in a Gigahertz transverse electromagnetic (GTEM) cell at different levels of non thermal specific absorption rate (SAR), which was calculated using the finite difference time domain (FDTD) technique. Using the immunohistochemistry technique, we studied the expression of HSP-90 protein and morphological changes in tissues thyroid gland. Ninety minutes after the radiation of the central and peripheral follicles increased in size while the peripheral wall thickness suffered a decrease in size with the highest SAR exposure. Twenty four hours after radiation central and peripheral follicles decrease in size with the SAR of 0.4 ± 12×10-3. Likewise with repeated exposure showed a decrease in the size of the follicles (peripheral and central). Morphological changes in the thyroid gland after radiation indicate acute or repeated stress adaptation in thyroid tissue in the hypothalamic-thyroid

Electromagnetic fields at 2.45 GHz trigger changes in heat shock proteins 90 and 70 without altering apoptotic activity in rat thyroid gland

Summary Non-ionizing radiation at 2.45 GHz may modify the expression of genes that codify heat shock proteins (HSP) in the thyroid gland. Using the enzyme-linked immunosorbent assay (ELISA) technique, we studied levels of HSP-90 and HSP-70. We also used hematoxilin eosin to look for evidence of lesions in the gland and applied the DAPI technique of fluorescence to search for evidence of chromatin condensation and nuclear fragmentation in the thyroid cells of adult female Sprague-Dawley rats. Fifty-four rats were individually exposed for 30 min to 2.45 GHz radiation in a Gigahertz transverse electromagnetic (GTEM) cell at different levels of non-thermal specific absorption rate (SAR), which was calculated using the finite difference time domain (FDTD) technique. Ninety minutes after radiation, HSP-90 and HSP-70 had decreased significantly (P<0.01) after applying a SAR of 0.046±1.10 W/Kg or 0.104±5.10−3 W/Kg. Twenty-four hours after radiation, HSP-90 had partially recovered and HSP-70 had recovered completely. There were few indications of lesions in the glandular structure and signs of apoptosis were negative in all radiated animals. The results suggest that acute sub-thermal radiation at 2.45 GHz may alter levels of cellular stress in rat thyroid gland without initially altering their anti-apoptotic capacity