DEVELOPMENT OF A RADIOIMMUNOASSAY FOR α-MELANOCYTE-STIMULATING HORMONE IN THE RAT

1975 ◽  
Vol 67 (3) ◽  
pp. 385-395 ◽  
Author(s):  
A. J. THODY ◽  
R. J. PENNY ◽  
DEL CLARK ◽  
CHRISTINE TAYLOR
Keyword(s):  
Single Injection ◽  
Rat Plasma ◽  
Anterior Lobe ◽  
Adult Rats ◽  
Rat Serum ◽  
Melanocyte Stimulating Hormone ◽  
Neurointermediate Lobe ◽  
Specific Radioimmunoassay ◽  
The Mean ◽  
Stimulating Hormone

SUMMARY A sensitive and specific radioimmunoassay for α-melanocyte-stimulating hormone (α-MSH) was developed. Extracts of the neurointermediate lobe of the rat produced displacement curves which were parallel to those obtained with synthetic α-MSH. The mean immunoreactive a-MSH concentration in neurointermediate lobes from normal adult rats was 2768 ± 200 (s.e.m.) ng/lobe. This accounted for approximately 78% of the MSH activity of the neurointermediate lobe as measured by bioassay. Much lower levels of immunoreactive α-MSH were found in the anterior lobe of the rat. Extracts of rat serum and plasma also contained immunoreactive α-MSH and the mean level was found to be 237 ± 20 pg/ml. This was slightly lower than the level measured in rat plasma by bioassay. Increased levels of α-MSH were found in plasma of rats 1 and 3 h after a single injection of trifluoperazine and after 1·5 min of ether anaesthesia. These changes were reflected by decreases in the α-MSH content of the neurointermediate lobe.

GABA-ergic control of α-Melanocyte-Stimulating Hormone (α-MSH) release by frog neurointermediate lobe in vitro

1986 ◽  
Vol 17 (5) ◽  
pp. 717-723 ◽  
Author(s):  
S. Adjeround ◽  
M.C. Tonon ◽  
M. Lamacz ◽  
E. Leneveu ◽  
M.E. Stoeckel ◽  
...  
Keyword(s):  
Melanocyte Stimulating Hormone ◽  
Neurointermediate Lobe ◽  
Stimulating Hormone

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).

scholarly journals Structural studies of α-melanocyte-stimulating hormone and a novel β-melanocyte-stimulating hormone from the neurointermediate lobe of the pituitary of the dogfish Squalus acanthias

1974 ◽  
Vol 141 (2) ◽  
pp. 439-444 ◽  
Author(s):  
Hugh P. J. Bennett ◽  
Philip J. Lowry ◽  
Colin McMartin ◽  
Alexander P. Scott
Keyword(s):  
Sequence Data ◽  
Mammalian Species ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Squalus Acanthias ◽  
Melanocyte Stimulating Hormone ◽  
Neurointermediate Lobe ◽  
C Terminus ◽  
Stimulating Hormone

A melanocyte-stimulating hormone (MSH) has been isolated from extracts of the neurointermediate lobe of the pituitary of the dogfish Squalus acanthias by gel-filtration and ion-exchange chromatography. It had approximately 1% of the potency of mammalian α-MSH on bioassays in vitro on frog skin and dogfish skin. Sequence analysis revealed it to be a hexadecapeptide with the following primary structure: Asp-Gly-Asp-Asp-Tyr-Lys-Phe-Gly-His-Phe-Arg-Trp-Ser-Val-Pro-Leu. It appears to be related to the β-MSH species of mammalian species but has only the sequence -His-Phe-Arg-Trp- in common with the heptapeptide core -Met-Glu-His-Phe-Arg-Trp-Gly- which is characteristic not only of the MSH peptides but also of the adrenocorticotrophins and lipotrophins studied so far. An α-MSH was also isolated, 50% of which was amidated at the C-terminus group. Sequence data from this study taken in conjunction with those from a previous study (Lowry & Chadwick, 1970b) revealed it to be a tridecapeptide which is identical with the N-terminal sequence of dogfish adrenocorticotrophin.

THE SEPARATION OF DIFFERENT FORMS OF MELANOCYTE-STIMULATING HORMONE FROM THE RAT NEUROINTERMEDIATE LOBE BY POLYACRYLAMIDE GEL ELECTROPHORESIS, WITH A NOTE ON RAT NEUROPHYSINS

1973 ◽  
Vol 57 (3) ◽  
pp. 393-NP ◽  
Author(s):  
BRIDGET I. BAKER
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Polyacrylamide Gels ◽  
Alkaline Ph ◽  
Melanocyte Stimulating Hormone ◽  
Neurointermediate Lobe ◽  
Stimulating Hormone

SUMMARY Extracts of rat neurointermediate lobes were subjected to electrophoresis on polyacrylamide gels at both acidic and alkaline pH. Melanocyte-stimulating hormone (MSH) was located in the gels by the Anolis skin method and was associated with bands of stainable material. Three bands with MSH activity were located after electrophoresis on acidic gels and two bands after electrophoresis on alkaline gels. The identity of these bands is discussed. Two further bands on the alkaline gels were associated with neurophysins.

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