Hormone-induced modifications of free tyrosine in the rat thyroid gland.
The concentrations of free tyrosine in liver, muscle, kidney and thyroid gland were determined in separate groups of rats maintained on a low iodine diet and treated with intraperitoneal injections of thyroxine (T 4), thyrotrophin (TSH) and TSH plus propylthiouracil (PTU). Groups of hypophysectomized rats also were given T 4. Significant changes in tissue tyrosine were generally confined to the thyroid gland. Animals treated with T 4 showed a decrease of mean thyroid tyrosine from 113.3 +/- 17.9 (S.D.) mug/g wet weight of gland to 76.2 +/- 5.7 mug/g (P < 0.01). Although there was little change in content when TSH was given alone, a significant increase in tyrosine levels was observed when TSH plus PTU were administered (P < 0.01). In hypophysectomized rats thyroid tyrosine decreased and was further lowered (to 46.0 +/- 3.1 mug/g; P < 0.05) by T 4 treatment. When tyrosine concentrations were expressed in relation to ribonucleic acid (RNA) or protein content of the assayed gland, all differences in tyrosine content became greater.
D000818:Animals; D007016:Hypophysectomy; D007456:Iodine Isotopes; D009929:Organ Size; D010910:Pituitary Irradiation; D011441:Propylthiouracil / Q000494:pharmacology*; D012313:RNA / Q000032:analysis; D051381:Rats; D013961:Thyroid Gland / Q000032:analysis* / Q000033:anatomy & histology / Q000187:drug effects; D013972:Thyrotropin / Q000494:pharmacology*; D013974:Thyroxine / Q000494:pharmacology*; D014443:Tyrosine / Q000032:analysis* / Q000378:metabolism
D007456:Iodine Isotopes; D014443:Tyrosine; D012313:RNA; D011441:Propylthiouracil; D013972:Thyrotropin; D013974:Thyroxine
Endocrinology. 1959 Jul;65(1):101-5
13663854
Endocrinology. 1959 Jan;64(1):149-59
13619570
Endocrinology. 1964 Feb;74:273-8
14122534
J Lab Clin Med. 1957 Nov;50(5):733-6
13476030
J Clin Endocrinol Metab. 1962 Dec;22:1242-50
13930165
J Biol Chem. 1953 Dec;205(2):795-802
13129258
Biochim Biophys Acta. 1962 Apr 23;58:563-74
14456681
Endocrinology. 1962 Apr;70:492-504
13884895
Endocrinology. 1963 Jul;73:103-7
13974151
J Clin Endocrinol Metab. 1964 Aug;24:691-8
14202747
J Biol Chem. 1962 Sep;237:2898-902
14489619
Proc Soc Exp Biol Med. 1956 Oct;93(1):13-5
13370562
J Pharmacol Exp Ther. 1963 May;140:229-35
13989973
Biochem Biophys Res Commun. 1964 Feb 18;15(1):82-6
5835379
Endocrinology. 1956 Jan;58(1):23-32
13285443
Biochem J. 1963 Jan;86:86-92
13943849
Proc Soc Exp Biol Med. 1957 Mar;94(3):517-20
13408311
Endocrinology. 1961 Jun;68:924-31
13733193
Endocrinology. 1962 Nov;71:816-21
13949840
J Biol Chem. 1959 Jun;234(6):1530-3
13654411
Endocrinology. 1961 Jun;68:914-23
13755674
Endocrinology. 1963 Jan;72:100-5
13949841
Endocrinology. 1963 Aug;73:155-64
14076192
Clin Chim Acta. 1962 Jan;7:50-4
13921829
J Clin Invest. 1963 Feb;42:239-48
13944203