concanavalin-a and Hyperthyroidism

We have studied the effect of thyroid disfunction during the postnatal period, on the serum and brain levels of rat alpha-fetoprotein (AFP) and albumin. Hypothyroidism was induced by treatment of pregnant rats and their newborn pups with 2-mercapto-1-methylimidazole(methimazole). Hyperthyroidism was provoked in newborns by daily injections of thyroxine (0.25 micrograms/g body wt) from the 3rd postnatal day weaning. Impaired growth, lower brain size, altered behaviour and morphological features observed were according to an altered thyroid status. Hypothyroid rats showed a significantly reduction in serum AFP concentration (78% of control values at 8 days of age) and a slight increase in that of albumin. level could be appreciated. Thyroxine supplementation (0.2 micrograms/rat/day) corrected most of these alterations. Hyperthyroidism induced a drastic fall in both serum and brain AFP levels (about 48% of the corresponding control values). Albumin concentration in serum was augmented significantly from the 12th postnatal day, but its brain levels did not change significantly. In hyperthyroid rats, a significant reduction (37% relative to controls) in the concanavalin A-non reactive microform of AFP, was observed. This alteration of the glycosylation pattern of AFP could be due to the inhibition by thyroxine of the activity of the hepatic enzyme GlcNAc-transferase III.

Topics: Aging; alpha-Fetoproteins; Animals; Animals, Newborn; Body Weight; Brain; Concanavalin A; Glycosides; Hyperthyroidism; Hypothyroidism; Immunoelectrophoresis, Two-Dimensional; Rats; Rats, Inbred Strains; Serum Albumin; Thyroxine

Topics: Animals; Antibody Formation; Body Weight; Chickens; Concanavalin A; Hyperthyroidism; Immunity; Male; Organ Size; Propylthiouracil; Spleen; Thymus Gland; Thyroid Gland; Thyroxine

A highly sensitive radioimmunoassay procedures for the measurement of serum hTSH is described which permits delineation of the entire range of values in normal subjects (0.5-4.5 microU/ml). The procedure involves the concentration of hTSH from serum by adsorption to concanavalin A covalently bound to 4B Sepharose, Lactoperoxidase iodination of hTSH, and disequilibrium assay conditions. This method utilizes commonly available radioimmunoassay materials and is convenient to perform. Our results with this assay show that patients with thyrotoxicosis of a variety of etiologies have serum hTSH levels suppressed well below the normal range.

Topics: Adolescent; Adult; Chromatography, Gel; Concanavalin A; Humans; Hyperthyroidism; Immune Sera; Iodine; Middle Aged; Radioimmunoassay; Thyrotropin