Tratamiento con TRIAC en pacientes pediátricos con deficiencia de MCT8 / Treatment with TRIAC in pediatric patients with MCT8

Los transportadores de monocarboxilatos (MCT) permiten el ingreso celular de hormonas tiroideas, especialmente en el sistema nervioso central (SNC), donde son indispensables para el neurodesarrollo. La deficiencia de MCT8 produce la combinación de hipotiroidismo en SNC e hipertiroidismo periférico, caracterizada por T3 elevada. El único tratamiento actualmente disponible es el ácido 3,3',5-triyodotiroacético (TRIAC), un análogo de hormonas tiroideas que tiene como objetivo mejorar la tirotoxicosis periférica y prevenir la progresión del deterioro neurológico. En el presente artículo, se evalúan las características clínicas, imagenológicas, bioquímicas y genéticas de 4 pacientes con deficiencia de MCT8 tratados con TRIAC hasta la fecha, las dosis utilizadas y la respuesta al tratamiento.

Monocarboxylate transporters (MCTs) allow the cellular entry of thyroid hormones, especially into the central nervous system (CNS), where they are crucial for neurodevelopment. MCT8 deficiency results in the combination of hypothyroidism in the CNS and peripheral hyperthyroidism, characterized by elevated T3 levels. The only treatment currently available is 3,3',5-triiodothyroacetic acid (TRIAC), a thyroid hormone analogue aimed at improving peripheral thyrotoxicosis and preventing the progression of neurological impairment. Here we assess the clinical, imaging, biochemical, and genetic characteristics of 4 patients with MCT8 deficiency who have received TRIAC to date, the doses used, and the response to treatment.

Treatment with TRIAC in pediatric patients with MCT8. / Tratamiento con TRIAC en pacientes pediátricos con deficiencia de MCT8.

Monocarboxylate transporters (MCTs) allow the cellular entry of thyroid hormones, especially into the central nervous system (CNS), where they are crucial for neurodevelopment. MCT8 deficiency results in the combination of hypothyroidism in the CNS and peripheral hyperthyroidism, characterized by elevated T3 levels. The only treatment currently available is 3,3',5-triiodothyroacetic acid (TRIAC), a thyroid hormone analogue aimed at improving peripheral thyrotoxicosis and preventing the progression of neurological impairment. Here we assess the clinical, imaging, biochemical, and genetic characteristics of 4 patients with MCT8 deficiency who have received TRIAC to date, the doses used, and the response to treatment.

Los transportadores de monocarboxilatos (MCT) permiten el ingreso celular de hormonas tiroideas, especialmente en el sistema nervioso central (SNC), donde son indispensables para el neurodesarrollo. La deficiencia de MCT8 produce la combinación de hipotiroidismo en SNC e hipertiroidismo periférico, caracterizada por T3 elevada. El único tratamiento actualmente disponible es el ácido 3,3',5-triyodotiroacético (TRIAC), un análogo de hormonas tiroideas que tiene como objetivo mejorar la tirotoxicosis periférica y prevenir la progresión del deterioro neurológico. En el presente artículo, se evalúan las características clínicas, imagenológicas, bioquímicas y genéticas de 4 pacientes con deficiencia de MCT8 tratados con TRIAC hasta la fecha, las dosis utilizadas y la respuesta al tratamiento.

Effect of acute swimming exercise at different intensities but equal total load over metabolic and molecular responses in swimming rats.

Acute metabolic and molecular response to exercise may vary according to exercise's intensity and duration. However, there is a lack regarding specific tissue alterations after acute exercise with aerobic or anaerobic predominance. The present study investigated the effects of acute exercise performed at different intensities, but with equal total load on molecular and physiological responses in swimming rats. Sixty male rats were divided into a control group and five groups performing an acute bout of swimming exercise at different intensities (80, 90, 100, 110 and 120% of anaerobic threshold [AnT]). The exercise duration of each group was balanced so all groups performed at the same total load. Gene expression (HIF-1α, PGC-1α, MCT1 and MCT4 mRNA), blood biomarkers and tissue glycogen depletion were analyzed after the exercise session. ANOVA One-Way was used to indicate statistical mean differences considering 5% significance level. Blood lactate concentration was the only biomarker sensitive to acute exercise, with a significant increase in rats exercised above AnT intensities (p < 0.000). Glycogen stores of gluteus muscle were significantly reduced in all exercised animals in comparison to control group (p = 0.02). Hepatic tissue presented significant reduction in glycogen in animals exercised above AnT (p = 0.000, as well as reduced HIF-1α mRNA and increased MCT1 mRNA, especially at the highest intensity (p = 0.002). Physiological parameters did not alter amongst groups for most tissues. Our results indicate the hepatic tissue alterations (glycogen stores and gene expressions) in response to different exercise intensities of exercise, even with the total load matched.