scholarly journals α-Melanocyte-stimulating-hormone precursors in the pig pituitary

1986 ◽  
Vol 235 (3) ◽  
pp. 715-722 ◽  
Author(s):  
M Fenger
Keyword(s):  
Adrenocorticotropic Hormone ◽  
Anterior Lobe ◽  
Intermediate Lobe ◽  
Reverse Phase ◽  
Melanocyte Stimulating Hormone ◽  
Pig Pituitaries ◽  
Stimulating Hormone

The occurrence of intermediates from the processing of ACTH-(1-39) [adrenocorticotropic hormone-(1-39)] to alpha-melanocyte-stimulating hormone was investigated in normal pig pituitaries by the use of sensitive and specific radioimmunoassays for ACTH-(1-13), ACTH-(1-14), ACTH-(1-13)-NH2 and ACTH-(1-39). Fractionation by reverse-phase h.p.l.c. revealed ACTH(1-17) and their acetylated analogues. The intermediate lobe contained NO-diacetyl-ACTH-(1-13)-NH2, N-acetyl-ACTH-(1-13)-NH2 and ACTH-(1-13)-NH2. In addition, the corresponding ACTH-(1-14) peptides (the glycine-extended precursor of the amidated peptides) were detected in lower amounts in both the intermediate lobe and the anterior lobe. ACTH-(1-17), ACTH-(1-13) and their acetylated analogues could not be detected in the anterior lobe or the intermediate lobe. The results suggest that an endopeptidase initially cleaves ACTH-(1-39) at the Lys-16-Arg-17 bond. ACTH-(1-16) is then processed by a pituitary carboxypeptidase to ACTH-(1-14) and ACTH-(17-39) by the aminopeptidase to ACTH-(18-39).

Endocrinological evaluation of ACTH-secreting pituitary microadenomas: their location and α-melanocyte stimulating hormone immunoreactivity

1992 ◽  
Vol 76 (6) ◽  
pp. 944-947 ◽  
Author(s):  
Takashi Nagaya ◽  
Akio Kuwayama ◽  
Hisao Seo ◽  
Nobuhiro Tsukamoto ◽  
Nobuo Matsui ◽  
...  
Keyword(s):  
Cushing’S Disease ◽  
Anterior Lobe ◽  
Cushing's Disease ◽  
Lower Sensitivity ◽  
Intermediate Lobe ◽  
Posterior Lobe ◽  
Content Type ◽  
Melanocyte Stimulating Hormone ◽  
Acth Secreting ◽  
Stimulating Hormone

✓ It has been hypothesized by Lamberts and coworkers in their analysis of 15 cases that adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas may be derived from either the anterior lobe or the intermediate lobe. The intermediate lobe type of Cushing's disease is thought to be controlled through a hypothalamic pathway and is characterized by hyperprolactinemia, suppressibility of Cortisol with bromocriptine, and lower sensitivity to dexamethasone. The authors investigated the validity of this hypothesis in 125 cases of ACTH-secreting pituitary microadenomas by analyzing the endocrine findings, the locations of the microadenomas, and α-melanocyte stimulating hormone (α-MSH) immunoreactivity in the adenoma cells. No significant differences in the basal hormone levels, Cortisol suppressibility with bromocriptine, sensitivity to dexamethasone, and recurrence rate were observed between patients with the microadenoma adjacent to the posterior lobe (considered typical of the intermediate lobe-derived tumor) or those with the microadenoma located in the anterior lobe. The locations of the microadenoma were not correlated with α-MSH immunoreactivity in the adenoma cells. No significant differences in endocrine findings were noticed between adenomas positive or negative for α-MSH. Thus, Cushing's disease cannot be simply divided into either the anterior lobe type or the intermediate lobe type by endocrinological evaluation as described by Lamberts, et al.

DISTRIBUTION OF RADIOACTIVITY IN THE ORGANS OF THE RAT AND MOUSE AFTER INJECTION OF [125I]α-MELANOCYTE-STIMULATING HORMONE

1975 ◽  
Vol 64 (2) ◽  
pp. 237-241 ◽  
Author(s):  
A. DUPONT ◽  
A. J. KASTIN ◽  
F. LABRIE ◽  
G. PELLETIER ◽  
R. PUVIANI ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Direct Measurement ◽  
Whole Body ◽  
Intermediate Lobe ◽  
High Uptake ◽  
Melanocyte Stimulating Hormone ◽  
Whole Body Autoradiography ◽  
Very High ◽  
Stimulating Hormone

SUMMARY The distribution of radioactivity after intrajugular injection of 125Ilabelled α-melanocyte-stimulating hormone (α-MSH) was studied by whole-body autoradiography of the mouse and by direct measurement of radioactivity in individual organs of the rat. Very high uptake of radioactivity in the pineal gland was measured 5 min after the injection of [125I]α-MSH. Lower levels of accumulation of radioactivity were found in the kidney and in the posterior (including intermediate) lobe of the pituitary. High uptake was also found in the thyroid, stomach, and oesophagus. The specificity of uptake of [125I] α-MSH into the pineal and pituitary is suggested by the very low uptake of Na125I into those tissues.

scholarly journals Plasma profiles of adrenocorticotropic hormone, cortisol, α-melanocyte-stimulating hormone, and growth hormone in dogs with pituitary-dependent hyperadrenocorticism before and after hypophysectomy

2006 ◽  
Vol 190 (3) ◽  
pp. 601-609 ◽  
Author(s):  
J M Hanson ◽  
H S Kooistra ◽  
J A Mol ◽  
E Teske ◽  
B P Meij
Keyword(s):  
Plasma Cortisol ◽  
Adrenocorticotropic Hormone ◽  
Plasma Concentrations ◽  
Pulse Frequency ◽  
Cortisol Concentration ◽  
Melanocyte Stimulating Hormone ◽  
Plasma Cortisol Concentration ◽  
Before And After ◽  
Basal Plasma ◽  
Stimulating Hormone

The 6-h plasma profiles of adrenocorticotropic hormone (ACTH), cortisol, α-melanocyte-stimulating hormone (α-MSH), and GH were studied in 17 dogs with pituitary-dependent hyperadrenocorticism (PDH) before and after hypophysectomy. The aim of the study was to investigate the relation between the hormone profile characteristics and recurrence of PDH after surgery. The hormones were secreted in a pulsatile fashion. The basal plasma cortisol concentration and area under the curve (AUC) for cortisol were significantly higher in the PDH cases than in eight controls. The characteristics of the plasma profiles of ACTH and α-MSH were not significantly different between the PDH cases and the controls. In the PDH cases, less GH was secreted in pulses than in the controls, but the difference was not significant. The basal plasma cortisol concentration, the AUC for ACTH and cortisol, and the pulse frequency of ACTH and cortisol decreased significantly after hypophysectomy for the group of PDH cases. The basal plasma concentrations of ACTH and α-MSH, the AUC for α-MSH, and the characteristics of the plasma GH profiles of the PDH cases remained unchanged after hypophysectomy. No pulses of α-MSH were observed after hypophysectomy. The co-occurrence between the ACTH and cortisol pulses decreased significantly with hypophysectomy. The postoperative pulse frequency of ACTH was the only characteristic with predictive value for the recurrence of PDH after hypophysectomy. The results of this study demonstrate that ACTH, cortisol, α-MSH, and GH are secreted in a pulsatile fashion in dogs with PDH. Hypophysectomy effectively reduces the secretion of ACTH and cortisol. The presence of ACTH pulses after hypophysectomy is a risk factor for the recurrence of hyperadrenocorticism.

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