ASSOCIATION BETWEEN METABOLIC SYNDROME AND THE DISTURBANCE OF THE HYPOTHALAMUS PITUITARY THYROID AXIS IN A MALE SPRAGUE-DAWLEY RAT MODEL
El Sindrome Metabólico (SM) es una constelación de entidades neuroendocrinas que contribuye a estados crónicos pro inflamatorios. A pesar de que el eje tiroideo se encarga de mantener el equilibrio metabólico, poco se sabe sobre su papel en el SM. Este trabajo evaluó la asociación del SM con la alteración del eje hipotalámico hipofisario tiroideo (EHHT) en un modelo de ratas macho Sprague-Dawley (SD). 32 ratas de 5 semanas de edad fueron divididas en dos grupos, control y experimental. Durante 28 semanas, las controles recibieron una dieta hipoglicémica y las experimentales, una dieta rica en carbohidratos y grasas. Mediciones seriales simultáneas de presión arterial sistólica (PAS) y frecuencia cardiaca fueron tomadas. Luego, las esperimentales se subclasificaron como “normotensas” e “hipertensas”. Finalmente, todas fueron sacrificadas mediante punción cardiaca para medir glucosa (GLc), insulina, hormona estimulante de la tiroides (TSH), tetraiodotironina (T4 libre), triglicéridos (TAG) y colesterol LDL (LDL). Se encontraron diferencias significativas (p<0.05) en las siguientes mediciones: peso entre controles vs. normotensas e hipertensas; PAS final menor en controles y normotensas vs. hipertensas; GLc aumentó en normotensas e hipertensas vs. controles, como en normotensas vs. hipertensas; insulina mayor en controles vs. normotensas e hipertensas; LDL mayor en normotensas e hipertensas vs. controles, como en normotensas vs. hipertensas; TAG mayor en normotensas e hipertensas vs. controles, como en hipertensas vs. normotensas; TSH aumentó en normotensas e hipertensas vs. controles, como en hipertensas vs. normotensas y HOMA-IR mayor en controles vs. hipertensas. Los puntos de corte de los percentiles de TSH y T4 libre también fueron calculados (p<0.05). De las hipertensas, una desarrolló hipotiroidismo; cuatro, hipotiroidismo primario y tres, hipotiroidismo subclínico. No hay pruebas suficientes para rechazar una asociación entre el hipotiroidismo y el SM con hipertensión en este modelo de ratas macho SD.
ASSOCIATION BETWEEN METABOLIC SYNDROME AND THE DISTURBANCE OF THE HYPOTHALAMUS PITUITARY THYROID AXIS IN A MALE SPRAGUE-DAWLEY RAT MODEL
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DOI: 10.22533/at.ed.1592108108
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Palavras-chave: Sindrome Metabólico, hormona tiroidea, Sprague-Dawley
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Keywords: Metabolic Syndrome, thyroid hormone, Sprague-Dawley
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Abstract:
Metabolic syndrome (MetS) is a constellation of neuroendocrine entities that contribute to chronic pro-inflammatory states. Though the thyroid axis is responsible for the energetic maintenance, little is known about its role in MetS. This work evaluated the association between MetS and the disturbance of the hypothalamic pituitary thyroid (HPT) axis in male Sprague-Dawley (SD) rats. 32 5-week-old rats were divided into control and experimental groups. For 28 weeks, control group received a hypoglycemic diet and experimental group a high-carbohydrate and fat diet. Serial measurements of systolic blood pressure (SBP) and heart rate were taken simultaneously. Then, the latter was sub-classified as normotensive and hypertensive. Rats were sacrificed by heart puncture and blood analysis was done [glucose (GLc), triglycerides (TAG), cholesterol LDL (LDL), insulin, thyroid-stimulating hormone (TSH) and free tetra iodine thyroxine (Free T4)]. Significant differences were found in weight between control and normotensive rats, and control and hypertensive rats (p<0.05). Final SBP measurement lower in control, and normotensive rats vs. hypertensive rats (p<0.05). GLc increased in normotensive, and hypertensive rats vs. control group (p<0.05); same in normotensive vs. hypertensive rats. Insulin higher among control group vs. normotensive, and hypertensive rats (p<0.05). LDL higher in normotensive, and hypertensive rats vs. control group; same in normotensive vs. hypertensive. TAG higher in normotensive, and hypertensive rats vs. control group; same in hypertensive vs. normotensive (p<0.05). TSH increased in normotensive, and hypertensive rats vs. control group (p<0.05). Difference also found in hypertensive vs. normotensive. HOMA-IR higher in control vs. hypertensive group (p<0.05). Free T4 and TSH percentiles’ critical values were calculated (p<0.05). In hypertensive rats, one developed hypothyroidism; four, primary hypothyroidism and three, subclinical hypothyroidism. There is no sufficient evidence to reject an association between hypothyroidism and MetS with hypertension in this male SD rat model.
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Número de páginas: 16
- Frine Samalvides Cuba
- Thalía Colmenares Arce
