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.

DISTRIBUTION OF RADIOACTIVITY IN THE ORGANS OF THE RAT AND MOUSE AFTER INJECTION OF l-[3H]PROLYL-l-LEUCYL-GLYCINAMIDE

1975 ◽  
Vol 64 (2) ◽  
pp. 243-NP ◽  
Author(s):  
A. DUPONT ◽  
F. LABRIE ◽  
G. PELLETIER ◽  
R. PUVIANI ◽  
D. H. COY ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Pineal Gland ◽  
Direct Measurement ◽  
Anterior Pituitary ◽  
Animal Species ◽  
Submaxillary Gland ◽  
Whole Body ◽  
Intermediate Lobe ◽  
Preferential Uptake ◽  
Good Agreement

SUMMARY The distribution of radioactivity after intrajugular injection of l-[3H]prolyl-l-leucyl-glycinamide has been studied by whole-body autoradiography in the mouse and by direct measurement of radioactivity in individual organs of the rat. There is good agreement between results obtained with the two techniques and animal species. High levels of radioactivity were found in the pineal gland, anterior pituitary, posterior (including intermediate) lobe of the pituitary, and epididymal and brown fat. Lower uptake of radioactivity occurred in the submaxillary gland, kidney, and adrenal gland. The preferential uptake of radioactivity by the pineal gland after injection of the labelled tripeptide suggests a role for this hypothalamic hormone in the control of pineal activity.

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).

ABILITY OF VARIOUS FACTORS TO OPPOSE THE STIMULATORY EFFECT OF DIBUTYRYL CYCLIC AMP ON THE RELEASE OF MELANOCYTE-STIMULATING HORMONE BY THE RAT PITUITARY IN VITRO

1976 ◽  
Vol 68 (2) ◽  
pp. 283-287 ◽  
Author(s):  
BRIDGET I. BAKER
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Inhibitory Effect ◽  
Aminobutyric Acid ◽  
Intermediate Lobe ◽  
Dibutyryl Cyclic Amp ◽  
Melanocyte Stimulating Hormone ◽  
Rat Pituitary ◽  
Stimulating Hormone

SUMMARY Various agents were tested for their ability to oppose the stimulatory effect of dibutyryl cyclic AMP on the release of the melanocyte-stimulating hormone from the rat neuro-intermediate lobe in vitro. Only dopamine exhibited an inhibitory effect; serotonin, γ-aminobutyric acid, tocinoic acid, tocinamide, the tripeptide Pro-Leu-Gly-NH2 and dibutyryl cyclic GMP were all ineffective.

scholarly journals Adrenocorticotrophic and melanocyte-stimulating peptides in the human pituitary

1974 ◽  
Vol 139 (3) ◽  
pp. 593-602 ◽  
Author(s):  
Alexander P. Scott ◽  
Philip J. Lowry
Keyword(s):  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Human Pituitary ◽  
Melanocyte Stimulating Hormone ◽  
Stimulating Hormone

The adrenocorticotrophic and melanocyte-stimulating peptides of the human pituitary were investigated by means of radioimmunoassay, bioassay and physicochemical procedures. Substantial amounts of adrenocorticotrophin and a peptide resembling β-lipotrophin were identified in pituitary extracts, but α-melanocyte-stimulating hormone, β-melanocyte-stimulating hormone and corticotrophin-like intermediate lobe peptide, which have been identified in the pars intermedia of pituitaries from other vertebrates, were not found. The absence of β-melanocyte-stimulating hormone appears to contradict previous chemical and radioimmunological studies. Our results suggest, however, that it is not a natural pituitary peptide but an artefact formed by enzymic degradation of β-lipotrophin during extraction.

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