[Function of growth hormone in the human energy continuum during physical exertion]. / Función de la hormona del crecimiento en el continuum energético humano durante el ejercicio físico.

A study has been carried out in 18 healthy sedentary males (controls) and 15 trained handball players. It was programmed two different tests on cycle-ergometer: Test 1 aerobic of progressive increments of load (1 W/kg/3 min) and Test 2 (A) anaerobic (4 W/kg, during 1.5 min) and after resting 10 min., Test 2 (B) till exhaustion. The blood samples were 10 ml each collected by antecubital vein catheterization. Before, during and post-exercise recovery period HG hormone, glycemia, lactate, and FFA were measured. It was found a correlation between HGH levels and substances of the energetic metabolism. The only exception was trained subjects test-2 possibly due to slower response of HGH. However FFA variation levels are correlated at the beginning with the increasing levels (p less than 0.001). It is concluded that HGH can play an important role on the turn-over to get fuel to contractile process from carbohydrates to free fatty acids.

[Importance of changes in plasmatic volume in the evaluation of TSH, L-T3 and L-T4, during muscular activity]. / Importancia de los cambios de volumen plasmático en la valoración de la TSH, L-T3 y L-T4, durante la actividad muscular.

The changes in plasma concentrations of TSH and thyroid hormones (L-T3 and L-T4), lactate, proteins and FFA were studied in 8 male volunteers undergoing maximal exercise during 12 min on the bicycle ergometer from 1 to 4 w/kg. Serial blood samples were taken at -30, 0, 3, 6, 9, 12, +3, +15 and +30 min intervals. All samples for TSH, L-T3 and L-T4 measurements were processed by radioimmunoassay. The possibility of interference in the RIA determination, with protein and FFA, has been studied in this work. However, in men the available evidence suggests that protein and FFA do not play an important role of interference in the determination methodology of thyroid hormone levels. This interpretation is in accordance with the fact that in men, plasma concentrations of thyroid hormones are related to changes in plasmatic volume, the intensity and the extended duration of the exercise.

[L-thyroxine and triiodo-L-thyronine in the cerebrospinal fluid and hypothalamo-hypophyseal axis of hyper- or hypothyroid rats]. / L-tiroxina y triiodo-L-tironina en líquido cefalorraquídeo y eje hipotálamo hipofisario de ratas, hiper- e hipotiroideas.

L-thyroxine and triiodo-L-thyronine concentrations in cerebrospinal fluid (CSF), hypothalamus and pituitary gland are measured in male albino-Wistar rats under several experimental thyroid disfunction : including hyperthyroidism induced by L-T3 and L-T4 treatments and surgical hypothyroidism. Radioimmunoassay is carried out by Nejad's method modified in this work. The pattern of thyroid hormone concentrations in CSF is similar to that in serum, but the values obtained are lower. Thyroid hormone concentrations in adenohypophysis as opposed to hypothalamus or cerebral cortex, show an inverse change to functional thyroid status.

[Changes in dehydrogenase glutamate in the rat brain caused by thyroid hormone deficiency]. / Alteraciones de la glutamato deshidrogenasa en áreas cerebrales de rata por deficiencia de hormonas tiroideas.

The dependent GDH-NADPH activity in adenohypophysis and other cerebral areas, has been studied in hypothyroid rats, in which hypothyroidism has been induced surgically. After thyroidectomy a decrease of GDH activity in limbic system (amygdala, septum and hippocampus), and an increase of this enzyme in cortex and hypothalamus have been found, with no changes in adenohypophysis. The alterations of GDH activity, induced by thyroidectomy, have been corrected, although not uniformly in the different brain areas after L-T3 treatment.

[Effect of experimental changes in thyroid function on oxidative metabolism and glutamate dehydrogenase activity in the limbic system of the rat]. / Efecto de las alteraciones experimentales de la función tiroidea sobre el metabolismo oxidativo y actividad de la glutamato deshidrogenasa en el sistema límbico de la rata.

The oxidative metabolism and GDH activity has been studied in the following regions of the brain: frontal cortex, as tissue control, adenohypophysis, hypothalamus and limbic system in adult male rats subjected to alterations of the thyroid function due to excess (by hyperthyroidism with L-thyroxine and thyrotoxicosis with Tri-iodothyronine) or defect (chronic hypothyroidism by thyroidectomy, 131-I treatment and low iodine diet). A different influence of the H.T. was observed in these animals according to the areas studied and the experimental situation induced. All this seems to indicate an oxidative metabolic pattern peculiar to each area of the brain following H.T. administration. On the other hand, the decrease of the QO2 in chronic hypothyroidism in the majority of the areas studied is remarkable. In GDH results activity increased or decreased depending on the absence or presence of thyroid hormones.