Changes in serum N-acetyl-beta-hexosaminidase levels after treatment of hypothyroid and hyperthyroid individuals with L-thyroxine and propylthiouracil.
Multiple serum samples were obtained from six hypothyroid and six hyperthyroid females, 11--17 years of age, over the course of their corrective treatment with L-thyroxine (LT4) and propylthiouracil (PTU), respectively. Sera were assayed for total N-acetyl-beta-hexosaminidase (HEX), the A (heat-labile) and B (heat-stable) isozymes, and total T4. HEX activity (total HEX A) in sera from hypothyroid (< 4 micrograms/dl T4) patients (total HEX: 518 +/- 66 nmol/60 min/ml, mean +/- S.D.; HEX A: 325 +/- 55; n = 5) was significantly lower than that of the euthyroid control group (total HEX: 638 +/- 77 (p  < 0.005); HEX A: 420 +/- 76 ( p < 0.01); n = 23); no difference in HEX B levels was noted. Serum samples from patients successfully treated for hypothyroidism via oral administration of LT4 (n = 12) displayed levels of total HEX (722 +/- 113) and HEX A (491 +/- 91) significantly higher than those of the control group (p < 0.01 in both cases); again, no change in levels of HEX B was observed. HEX activity in sera from hyperthyroid (> 13 micrograms/dl T4) individuals (total HEX: 839 +/- 96; HEX A: 540 +/- 74; HEX B: 299 +/- 52; n =20) was significantly higher than that of the control group (p < 0.005 in all cases). The depression of hormone activity to the euthyroid range by PTU was accompanied ay a decrease in enzyme activity to control levels (total HEX: 632 +/- 92; HEX A: 400 +/- 55; HEX B: 232 +/- 52; n = 16). Non-parametric analysis of the data shows highly significance differences between pre- and post-treatment enzyme levels (alpha < 0.001) in both hyper- and hypothyroid groups. Alteration of thyroid status, and specifically T4 level is, therefore, indicated to be a contributing factor in the regulation of serum HEX activity in humans, as evidenced by individual responsiveness to oral administration of this hormone, or inhibitors of its peripheral metabolism.
D000293:Adolescent; D002648:Child; D005260:Female; D054818:Hexosaminidase A; D054819:Hexosaminidase B; D006596:Hexosaminidases / Q000097:blood*; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy / Q000201:enzymology*; D007037:Hypothyroidism / Q000188:drug therapy / Q000201:enzymology*; D007527:Isoenzymes / Q000097:blood*; D011441:Propylthiouracil / Q000627:therapeutic use*; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use*; D001619:beta-N-Acetylhexosaminidases
D007527:Isoenzymes; D011441:Propylthiouracil; D006596:Hexosaminidases; D054818:Hexosaminidase A; D054819:Hexosaminidase B; D001619:beta-N-Acetylhexosaminidases; D013974:Thyroxine