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Endocrine, biochemical, and morphological studies of a pituitary adenoma secreting growth hormone, thyrotropin (TSH), and alpha-subunit: evidence for secretion of TSH with increased bioactivity.
J Clin Endocrinol Metab. 1986 Apr; 62(4):704-11.JC

Abstract

A 40-yr-old man who had acromegaly and hyperthyroidism due to a GH/TSH-secreting pituitary adenoma is described. Serum free T4 was 2.8 ng/dl, free T3 was 1.1 ng/dl, and TSH was 1.2-1.5 microU/ml; the latter was measured in an immunoradiometric assay with a sensitivity of 0.07 microU/ml. Serum TSH was immunologically identical to standard TSH and did not decrease during a T3 suppression test. Serum free alpha-subunit and the molar alpha-subunit to TSH ratio were high (6.1 ng/ml and 31.2, respectively). TRH administration induced significant increases in both GH (+129%) and alpha-subunit (+156%) levels. Conversely, dopamine infusion resulted in a decrease in serum GH (-66%) and alpha-subunit (-43%) levels, and subsequent administration of the dopamine antagonist sulpiride induced significant increases in both GH and alpha-subunit (+393% and +106%, respectively). Similarly, somatostatin infusion inhibited GH (-43%) and alpha-subunit (-61%) secretion. Serum TSH levels were not affected by TRH, dopamine, or somatostatin. The biological to immunological activity ratio of serum TSH purified by immunoaffinity chromatography and measured in an adenylate cyclase assay was significantly increased compared to that in serum from hypothyroid or euthyroid subjects [biological to immunological activity ratio, 6.9 +/- 0.2 (+/- SD) vs. 4.4 +/- 1.1; P less than 0.001]. In gel chromatography, the apparent mol wt of the patient's TSH was smaller than that of the controls. After adenomectomy, all of the altered parameters of pituitary function became normal. Double gold particle immunostaining of the adenomatous tissue showed that all of the cells contained secretory granules positive for GH and alpha-subunit, while very few cells were positive for TSH beta as well as GH and alpha-subunit. These data indicate that in this patient serum TSH had an apparent mol wt smaller than that of normal TSH and an increased biological activity which, along with the autonomous TSH secretion, account for hyperthyroidism in the presence of low normal TSH levels; alpha-subunit originated from the same adenomatous cells that secreted GH but not TSH, thus explaining the in vivo observation that alpha-subunit responses to several agents were dissociated from TSH responses and parallel to GH responses; and TSH and GH were colocalized in a minority of the neoplastic cells.

Authors

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Pub Type(s)

Case Reports
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

2419356

Citation

Beck-Peccoz, P, et al. "Endocrine, Biochemical, and Morphological Studies of a Pituitary Adenoma Secreting Growth Hormone, Thyrotropin (TSH), and Alpha-subunit: Evidence for Secretion of TSH With Increased Bioactivity." The Journal of Clinical Endocrinology and Metabolism, vol. 62, no. 4, 1986, pp. 704-11.
Beck-Peccoz P, Piscitelli G, Amr S, et al. Endocrine, biochemical, and morphological studies of a pituitary adenoma secreting growth hormone, thyrotropin (TSH), and alpha-subunit: evidence for secretion of TSH with increased bioactivity. J Clin Endocrinol Metab. 1986;62(4):704-11.
Beck-Peccoz, P., Piscitelli, G., Amr, S., Ballabio, M., Bassetti, M., Giannattasio, G., Spada, A., Nissim, M., Weintraub, B. D., & Faglia, G. (1986). Endocrine, biochemical, and morphological studies of a pituitary adenoma secreting growth hormone, thyrotropin (TSH), and alpha-subunit: evidence for secretion of TSH with increased bioactivity. The Journal of Clinical Endocrinology and Metabolism, 62(4), 704-11.
Beck-Peccoz P, et al. Endocrine, Biochemical, and Morphological Studies of a Pituitary Adenoma Secreting Growth Hormone, Thyrotropin (TSH), and Alpha-subunit: Evidence for Secretion of TSH With Increased Bioactivity. J Clin Endocrinol Metab. 1986;62(4):704-11. PubMed PMID: 2419356.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Endocrine, biochemical, and morphological studies of a pituitary adenoma secreting growth hormone, thyrotropin (TSH), and alpha-subunit: evidence for secretion of TSH with increased bioactivity. AU - Beck-Peccoz,P, AU - Piscitelli,G, AU - Amr,S, AU - Ballabio,M, AU - Bassetti,M, AU - Giannattasio,G, AU - Spada,A, AU - Nissim,M, AU - Weintraub,B D, AU - Faglia,G, PY - 1986/4/1/pubmed PY - 1986/4/1/medline PY - 1986/4/1/entrez SP - 704 EP - 11 JF - The Journal of clinical endocrinology and metabolism JO - J Clin Endocrinol Metab VL - 62 IS - 4 N2 - A 40-yr-old man who had acromegaly and hyperthyroidism due to a GH/TSH-secreting pituitary adenoma is described. Serum free T4 was 2.8 ng/dl, free T3 was 1.1 ng/dl, and TSH was 1.2-1.5 microU/ml; the latter was measured in an immunoradiometric assay with a sensitivity of 0.07 microU/ml. Serum TSH was immunologically identical to standard TSH and did not decrease during a T3 suppression test. Serum free alpha-subunit and the molar alpha-subunit to TSH ratio were high (6.1 ng/ml and 31.2, respectively). TRH administration induced significant increases in both GH (+129%) and alpha-subunit (+156%) levels. Conversely, dopamine infusion resulted in a decrease in serum GH (-66%) and alpha-subunit (-43%) levels, and subsequent administration of the dopamine antagonist sulpiride induced significant increases in both GH and alpha-subunit (+393% and +106%, respectively). Similarly, somatostatin infusion inhibited GH (-43%) and alpha-subunit (-61%) secretion. Serum TSH levels were not affected by TRH, dopamine, or somatostatin. The biological to immunological activity ratio of serum TSH purified by immunoaffinity chromatography and measured in an adenylate cyclase assay was significantly increased compared to that in serum from hypothyroid or euthyroid subjects [biological to immunological activity ratio, 6.9 +/- 0.2 (+/- SD) vs. 4.4 +/- 1.1; P less than 0.001]. In gel chromatography, the apparent mol wt of the patient's TSH was smaller than that of the controls. After adenomectomy, all of the altered parameters of pituitary function became normal. Double gold particle immunostaining of the adenomatous tissue showed that all of the cells contained secretory granules positive for GH and alpha-subunit, while very few cells were positive for TSH beta as well as GH and alpha-subunit. These data indicate that in this patient serum TSH had an apparent mol wt smaller than that of normal TSH and an increased biological activity which, along with the autonomous TSH secretion, account for hyperthyroidism in the presence of low normal TSH levels; alpha-subunit originated from the same adenomatous cells that secreted GH but not TSH, thus explaining the in vivo observation that alpha-subunit responses to several agents were dissociated from TSH responses and parallel to GH responses; and TSH and GH were colocalized in a minority of the neoplastic cells. SN - 0021-972X UR - https://www.unboundmedicine.com/medline/citation/2419356/Endocrine_biochemical_and_morphological_studies_of_a_pituitary_adenoma_secreting_growth_hormone_thyrotropin__TSH__and_alpha_subunit:_evidence_for_secretion_of_TSH_with_increased_bioactivity_ L2 - https://academic.oup.com/jcem/article-lookup/doi/10.1210/jcem-62-4-704 DB - PRIME DP - Unbound Medicine ER -