Stimulation by melanocyte stimulating hormone and dibutyryl adenosine 3?,5?-cyclic monophosphate of DNA synthesis in human melanocytes in vitro

1976 ◽  
Vol 257 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Kitano Yukio
Keyword(s):  
Dna Synthesis ◽  
Cyclic Monophosphate ◽  
Melanocyte Stimulating Hormone ◽  
Human Melanocytes ◽  
Stimulating Hormone

Mechanism of the natriuretic action of gamma-melanocyte-stimulating hormone

1997 ◽  
Vol 272 (6) ◽  
pp. R1946-R1953 ◽  
Author(s):  
X. W. Chen ◽  
W. Z. Ying ◽  
J. P. Valentin ◽  
K. T. Ling ◽  
S. Y. Lin ◽  
...  
Keyword(s):  
Urinary Sodium Excretion ◽  
Right Atrial ◽  
Renal Nerves ◽  
Minor Role ◽  
Critical Element ◽  
Contralateral Kidney ◽  
Cyclic Monophosphate ◽  
Melanocyte Stimulating Hormone ◽  
Stimulating Hormone

To explore the mechanism underlying the natriuretic effect of gamma-melanocyte-stimulating hormone (gamma-MSH), we infused the peptide intravenously at 200 pmol/min into anesthetized rats. gamma-MSH led to a progressive increase in urinary sodium excretion (UNaV), whereas continuous infusion of the vehicle did not affect UNaV. Plasma immunoreactive gamma-MSH was nine times greater at 120 min after the start of the infusion than in vehicle-infused rats. Plasma atrial natriuretic peptide (ANP) concentration also increased as a consequence of the gamma-MSH infusion, and a strong correlation existed between the concentrations of the two peptides (n = 17, r = 0.81, P < 0.001). Urinary excretion of guanosine 3',5'-cyclic monophosphate and adenosine 3',5'-cyclic monophosphate increased as a result of the infusion. Antiserum to rat ANP blunted the natriuresis only slightly, suggesting that the increase in plasma ANP concentration was not a critical element in gamma-MSH natriuresis. gamma-MSH had no effect on ANP release from isolated rat right atrial strips superfused in vitro. Infusion of gamma-MSH (500 fmol/min) directly into one renal artery led to an ipsilateral natriuresis without change in UNaV from the contralateral kidney. Prior denervation of the infused kidney prevented the natriuresis resulting from intrarenal infusion. Intrarenal infusion of ANP (800 fmol/min) also produced ipsilateral natriuresis, which, however, was not affected by renal denervation. These studies confirm that the natriuretic action of gamma-MSH occurs primarily by an interaction with the renal nerves. Intravenous infusion of the peptide sufficient to produce a supraphysiological plasma gamma-MSH concentration also results in an increase in plasma ANP concentration; however, this increase at best plays only a minor role in the natriuresis following intravenous gamma-MSH infusion.

Alpha-melanocyte stimulating hormone and its analogue Nle4DPhe7 alpha-MSH affect morphology, tyrosinase activity and melanogenesis in cultured human melanocytes

1994 ◽  
Vol 107 (1) ◽  
pp. 205-211 ◽  
Author(s):  
G. Hunt ◽  
C. Todd ◽  
J.E. Cresswell ◽  
A.J. Thody
Keyword(s):  
Cholera Toxin ◽  
Tyrosinase Activity ◽  
Melanin Content ◽  
Melanocyte Stimulating Hormone ◽  
Human Melanocytes ◽  
The Common ◽  
In Vitro Effects ◽  
Stimulating Hormone

Although melanocyte stimulating hormone (MSH) peptides are known to stimulate pigmentation in man, previous reports suggest that human melanocytes are relatively unresponsive to these peptides in vitro. This may be related to the conditions under which the melanocytes were cultured. Thus, we have re-investigated the in vitro effects of MSH peptides using human melanocytes cultured in the absence of artificial mitogens. Human melanocytes were incubated with alpha-MSH or its potent analogue Nle4Dphe7 alpha-MSH for 3 days. After 18 hours, melanocyte morphology had evolved from mainly bipolar to dendritic in approximately 66% of cultures. Nle4DPhe7 alpha-MSH produced dose-related increases in both tyrosinase activity and melanin content although the degree of response was variable and tyrosinase activity was the relatively more responsive to the peptide. Similar results were obtained with alpha-MSH, but, although the effect on melanin content was similar to that of Nle4DPhe7 alpha-MSH, the effect on tyrosinase activity was less marked. The preliminary EC50 values for the actions of the MSH peptides suggest that they may be equipotent in their actions on human melanocytes. In addition, we have demonstrated that the common melanocyte mitogens 12-O-tetradecanoyl phorbol-13-acetate (TPA) and cholera toxin affect basal melanogenesis and modulate the effects of the MSH peptides. However, not all melanocyte cultures showed melanogenic responses to the MSH peptides. Ability to respond was unrelated to basal levels of tyrosinase activity or melanin content. In at least some cultures, morphological and melanogenic responses appear to be independent of one another.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of α-melanocyte-stimulating hormone (α-MSH)-like peptides in discrete regions of the rat brain. In vitro release of α-MSH from perifused hypothalamus and amygdala

1990 ◽  
Vol 513 (2) ◽  
pp. 299-307 ◽  
Author(s):  
Denis Tranchand Bunel ◽  
Catherine Delbende ◽  
Catherine Blasquez ◽  
Sylvie Je´gou ◽  
Hubert Vaudry
Keyword(s):  
Rat Brain ◽  
In Vitro Release ◽  
Melanocyte Stimulating Hormone ◽  
Vitro Release ◽  
Stimulating Hormone

scholarly journals Nle4DPhe7α-Melanocyte-Stimulating Hormone Increases the Eumelanin:Phaeomelanin Ratio in Cultured Human Melanocytes

1995 ◽  
Vol 104 (1) ◽  
pp. 83-85 ◽  
Author(s):  
Gillian Hunt ◽  
Sylvia Kyne ◽  
Kazumasa Wakamatsu ◽  
Shosuke Ito ◽  
Anthony J. Thody
Keyword(s):  
Melanocyte Stimulating Hormone ◽  
Human Melanocytes ◽  
Stimulating Hormone

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
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