title: [Response of thyrotropin (TSH) to the stimulation with hypothalamic releasing factor (TRF) in hypothyroid children].
abstract: The normal human serum thyrotropin (TSH) measured by radioimmunoassay in 36 children was 3.3 +/- 1.13 muUI/ml. No differences dependent on age or sex were found. Stimulation by intravenous injection of 100 mug of TRF has been carried out in 7 euthyroid children and in 14 with hypothyroidism. TSH was determined prior to, and during TRF stimulation. Among other thyroid tests included in this study were: serum T3 uptake, total thyroxine, serum protein-bound iodine, 131INa uptake and thyroid scanning. In the euthyroid children, TSH at zero time was 4.4 muUI/ml.; a significant increase was reached at 30-40 minutes. In 13 children with a light primary hypothyroidism, TSH was little increased in correlation with other parameters assessed. In two children with true primary hypothyroidism, TSH at zero time was X 465 muUI/ml., showing an increase at 30 minutes of X 550 muUL/ml. which was in agreement with the absence of thyroid tissue, showed by the scanning image and with the low concentration of thyroid hormones. The synthetic thyrotropin-releasing factor (TRF) should be a useful agent for clinical assessment of pituitary reserve. TSH, T3, T4 and T4I serum concentration measurement in pediatric age, makes possible to evaluate the physiopathology of the pituitary - thyroid axis.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013268:Stimulation, Chemical; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000502:physiology*; D013972:Thyrotropin / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
chemical_list: D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin
vernacular_title: Respuesta de la tirotrofina (TSH) a la estimulación con el factor liberador hipotalámico (TRF) en niños hipotiroideos