+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Characterization of gamma-melanotropin-like immunoreactivity and its secretion in an adrenocorticotropin-producing mouse pituitary tumor cell line



Characterization of gamma-melanotropin-like immunoreactivity and its secretion in an adrenocorticotropin-producing mouse pituitary tumor cell line



Endocrinology 111(2): 418-424



gamma MSH, a putative hormone in the N-terminal region of the ACTH/beta-endorphin (beta-EP) precursor protein, was studied by RIA with an antiserum against gamma 3MSH in ACTH-producing mouse pituitary tumor cells, AtT-20/D16v. Serial dilution of the culture medium or the cell extract gave parallel lines to the standard curve in the RIA for gamma MSH. Rat median eminence extracts enhanced the release of gamma MSH-like immunoreactivity (gamma MSH-LI) concomitant with ACTH-like immunoreactivity (ACTH-LI) and beta-EP-like immunoreactivity (beta-EP-LI). Dexamethasone suppressed the release of gamma MSH-LI as well as ACTH-LI and beta-EP-LI. Gel exclusion chromatography of the culture medium and the cell extract has revealed that gamma MSH-LI consists of two peaks; one eluted near the elution position of beta-lipotropin and the other near the elution position of beta-EP. There was no peak corresponding to the elution position of synthetic gamma 3MSH. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) has demonstrated that gamma MSH-LI migrated at five positions with molecular weights of 31K, 21-23K, 16-17K, 13-14K, and 3.8K, respectively. The 31K gamma MSH coincided with the migration position of 31K ACTH of 31K beta-EP, and 21-23K gamma MSH coincided with the position of 21-23K ACTH on SDS-PAGE. The 16-17K gamma MSH coincided with the mouse 16K fragment (reported by Eipper and Mains) of ACTH-beta-lipotropin precursor protein in the migration in SDS-PAGE and in immunoreactivity to anti-gamma MSH antiserum. [3H]Glucosamine was incorporated into 16K, 13K, and 3.8K gamma MSH. These results suggest that AtT-20/D16v cells produce gamma MSH-LIs with molecular weights of 31K, 21-23K, 16-17K, 13-14K, and 3.8K, and they are secreted concomitantly with ACTH-LI and beta-EP-LI.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 042513807

Download citation: RISBibTeXText

PMID: 6284479

DOI: 10.1210/endo-111-2-418


Related references

Gamma 1-Melanotropin-like immunoreactivity in bovine and human adrenocorticotropin-producing tissues. Journal of Clinical Endocrinology and Metabolism 56(5): 1080-1083, 1983

Concomitant secretion of adrenocorticotropin, beta-endorphin, and gamma-melanotropin from perfused pituitary tumor cells of Cushing's disease: effects of lysine vasopressin, rat median eminence extracts, thyrotropin-releasing hormone, and luteinizing hormone-releasing hormone. Journal of Clinical Endocrinology and Metabolism 52(1): 42-49, 1981

Sorting and secretion of adrenocorticotropin in a pituitary tumor cell line after perturbation of the level of a secretory granule-specific proteoglycan. Journal of Cell Biology 99(6): 2223-2230, 1984

The regional distribution of gamma 3-melanotropin-like peptides in bovine brain is correlated with adrenocorticotropin immunoreactivity but not with beta-endorphin. Regulatory Peptides 2(1): 43-52, 1981

Adrenocorticotropin secretion by mouse pituitary tumor cells in culture: the role of Ca+2 in stimulated and somatostatin-inhibited secretion. Endocrinology 113(1): 62-68, 1983

Existence of gamma-melanotropin (gamma-MSH)-like immunoreactivity in bovine and human pituitary glands. Biochemical and Biophysical Research Communications 94(1): 211-217, 1980

Molecular and functional characterization of GnRH receptors cloned from rat pituitary and a mouse pituitary tumor cell line. Biochemical and Biophysical Research Communications 191(3): 1139-1144, 1993

Reversal of dexamethasone inhibition of adrenocorticotropin release in a mouse pituitary tumor cell line either by growing cells in the absence of dexamethasone or by addition of hypothalamic extract. Endocrinology 102(1): 218-226, 1978

Muscarinic cholinergic inhibition of cyclic AMP formation and adrenocorticotropin secretion in mouse pituitary tumor cells. Biochemical and Biophysical Research Communications 114(1): 289-295, 1983

Characterization of a variant-producing tumor cell line from a heterogeneous strain BALB/cfC3H mouse mammary tumor. Cancer Research 41(4): 1293-1300, 1981

Forskolin stimulates adenylate cyclase activity, cyclic AMP accumulation, and adrenocorticotropin secretion from mouse anterior pituitary tumor cells. Journal of Neurochemistry 42(6): 1659-1666, 1984

A radio immunoassay for gamma 1 melanotropin and evidence that the smallest pituitary gamma melanotropin is amidated at the carboxyl terminus. Biochemical & Biophysical Research Communications 96(3): 1391-1399, 1980

A somatotropin-producing pituitary adenoma with an isolated adrenocorticotropin-producing pituitary adenoma in a female patient with acromegaly, subclinical Cushing's disease and a left adrenal tumor. Endocrine Journal 61(6): 589-595, 2014

A radioimmunoassay for gamma 1-melanotropin and evidence that the smallest pituitary gamma-melanotropin is amidated at the COOH-terminus. Biochemical and Biophysical Research Communications 96(3): 1393-1399, 1980

A pituitary tumor producing high molecular weight adrenocorticotropin-related peptides: clinical and cell culture studies. Journal of Clinical Endocrinology and Metabolism 58(1): 134-142, 1984