Tags

Type your tag names separated by a space and hit enter

Somatostatin receptors on thyrotropin-secreting pituitary adenomas: comparison with the inhibitory effects of octreotide upon in vivo and in vitro hormonal secretions.
J Clin Endocrinol Metab. 1992 Aug; 75(2):540-6.JC

Abstract

The in vivo and in vitro inhibitory effects of a somatostatin (SRIH) analog, octreotide, upon TSH, alpha-subunit, GH, and PRL have been studied, as well as SRIH receptors and their coupling to adenylate cyclase, in nine TSH-secreting pituitary adenomas. From in vivo and cell culture studies, the TSH- and alpha-subunit-secreting adenomas appeared heterogeneous, with four out of the nine tumors cosecreting GH and/or PRL. A single sc injection of octreotide (100 micrograms) lowered plasma concentration of TSH by 40 +/- 5% (mean +/- SE of 5), of alpha-subunit by 27 +/- 9% (n = 5), of GH by 60 +/- 5% (n = 4), and of PRL by 27 +/- 9% (n = 4). In cells cultures, octreotide (10(-8) mol/L) inhibited equally TSH, alpha-subunit, and GH release. 125I-Tyr0-DTrp8-SRIH binding sites were measurable in the nine TSH-secreting adenomas either on membrane preparations (n = 6; Bmax: 152 +/- 73 fmol/mg protein) or on frozen sections by radioautography (n = 3). Their density was variable among TSH adenomas and was lower than that measured in GH-secreting adenomas but higher than in nonfunctioning tumors. Two out of three TSH-secreting adenoma displayed an heterogeneous distribution of 125I-Tyr0-DTrp8-SRIH binding sites. 125I-Tyr0-DTrp8-SRIH specific binding was inhibited by guanosine triphosphate (GTP: 10(-4) mol/L). SRIH inhibited adenylate cyclase in 5/5 TSH-secreting adenomas and a good correlation (r = 0.92, P less than 0.02) was found between 125I-Tyr0-DTrp8-SRIH binding capacity (Bmax) and maximal adenylate cyclase inhibition by SRIH. These results demonstrate in vivo and in vitro inhibition of TSH, alpha-subunit, PRL, and GH secretion by octreotide in TSH-secreting pituitary adenomas. Functional SRIH receptors are present on these tumors and the effect of SRIH on hormonal secretion could be mediated, at least in part, by inhibition of adenylate cyclase. These findings support the medical treatment of this rare type of tumors by SRIH analogs.

Authors+Show Affiliations

INSERM U159, Centre P. Broca, Paris, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

1353505

Citation

Bertherat, J, et al. "Somatostatin Receptors On Thyrotropin-secreting Pituitary Adenomas: Comparison With the Inhibitory Effects of Octreotide Upon in Vivo and in Vitro Hormonal Secretions." The Journal of Clinical Endocrinology and Metabolism, vol. 75, no. 2, 1992, pp. 540-6.
Bertherat J, Brue T, Enjalbert A, et al. Somatostatin receptors on thyrotropin-secreting pituitary adenomas: comparison with the inhibitory effects of octreotide upon in vivo and in vitro hormonal secretions. J Clin Endocrinol Metab. 1992;75(2):540-6.
Bertherat, J., Brue, T., Enjalbert, A., Gunz, G., Rasolonjanahary, R., Warnet, A., Jaquet, P., & Epelbaum, J. (1992). Somatostatin receptors on thyrotropin-secreting pituitary adenomas: comparison with the inhibitory effects of octreotide upon in vivo and in vitro hormonal secretions. The Journal of Clinical Endocrinology and Metabolism, 75(2), 540-6.
Bertherat J, et al. Somatostatin Receptors On Thyrotropin-secreting Pituitary Adenomas: Comparison With the Inhibitory Effects of Octreotide Upon in Vivo and in Vitro Hormonal Secretions. J Clin Endocrinol Metab. 1992;75(2):540-6. PubMed PMID: 1353505.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Somatostatin receptors on thyrotropin-secreting pituitary adenomas: comparison with the inhibitory effects of octreotide upon in vivo and in vitro hormonal secretions. AU - Bertherat,J, AU - Brue,T, AU - Enjalbert,A, AU - Gunz,G, AU - Rasolonjanahary,R, AU - Warnet,A, AU - Jaquet,P, AU - Epelbaum,J, PY - 1992/8/1/pubmed PY - 1992/8/1/medline PY - 1992/8/1/entrez SP - 540 EP - 6 JF - The Journal of clinical endocrinology and metabolism JO - J Clin Endocrinol Metab VL - 75 IS - 2 N2 - The in vivo and in vitro inhibitory effects of a somatostatin (SRIH) analog, octreotide, upon TSH, alpha-subunit, GH, and PRL have been studied, as well as SRIH receptors and their coupling to adenylate cyclase, in nine TSH-secreting pituitary adenomas. From in vivo and cell culture studies, the TSH- and alpha-subunit-secreting adenomas appeared heterogeneous, with four out of the nine tumors cosecreting GH and/or PRL. A single sc injection of octreotide (100 micrograms) lowered plasma concentration of TSH by 40 +/- 5% (mean +/- SE of 5), of alpha-subunit by 27 +/- 9% (n = 5), of GH by 60 +/- 5% (n = 4), and of PRL by 27 +/- 9% (n = 4). In cells cultures, octreotide (10(-8) mol/L) inhibited equally TSH, alpha-subunit, and GH release. 125I-Tyr0-DTrp8-SRIH binding sites were measurable in the nine TSH-secreting adenomas either on membrane preparations (n = 6; Bmax: 152 +/- 73 fmol/mg protein) or on frozen sections by radioautography (n = 3). Their density was variable among TSH adenomas and was lower than that measured in GH-secreting adenomas but higher than in nonfunctioning tumors. Two out of three TSH-secreting adenoma displayed an heterogeneous distribution of 125I-Tyr0-DTrp8-SRIH binding sites. 125I-Tyr0-DTrp8-SRIH specific binding was inhibited by guanosine triphosphate (GTP: 10(-4) mol/L). SRIH inhibited adenylate cyclase in 5/5 TSH-secreting adenomas and a good correlation (r = 0.92, P less than 0.02) was found between 125I-Tyr0-DTrp8-SRIH binding capacity (Bmax) and maximal adenylate cyclase inhibition by SRIH. These results demonstrate in vivo and in vitro inhibition of TSH, alpha-subunit, PRL, and GH secretion by octreotide in TSH-secreting pituitary adenomas. Functional SRIH receptors are present on these tumors and the effect of SRIH on hormonal secretion could be mediated, at least in part, by inhibition of adenylate cyclase. These findings support the medical treatment of this rare type of tumors by SRIH analogs. SN - 0021-972X UR - https://www.unboundmedicine.com/medline/citation/1353505/Somatostatin_receptors_on_thyrotropin_secreting_pituitary_adenomas:_comparison_with_the_inhibitory_effects_of_octreotide_upon_in_vivo_and_in_vitro_hormonal_secretions_ L2 - https://academic.oup.com/jcem/article-lookup/doi/10.1210/jcem.75.2.1353505 DB - PRIME DP - Unbound Medicine ER -