Cardiovascular and renal actions of melanocyte-stimulating hormone peptides.

Abstract

PURPOSE OF REVIEW:

Melanocyte stimulating hormones (MSHs, melanocortins) have important roles in feeding and energy metabolism and in inflammation. Recent observations have uncovered major functions for these peptides, particularly gamma-MSH, in cardiovascular regulation and sodium metabolism.

RECENT FINDINGS:

Both alpha- and gamma-MSH acutely elevate blood pressure and heart rate through central stimulation of sympathetic nervous outflow. This action of alpha-MSH is mediated by the melanocortin 4 receptor (MC4R), whereas sympathetic nervous stimulation by gamma-MSH does not involve its receptor MC3R but rather is likely due to activation of a sodium channel in the central nervous system. In contrast, gamma-MSH deficiency in rodents, or disruption of MC3R, leads to marked salt-sensitive hypertension, again through a central mechanism: a small dose of exogenous peptide delivered into the cerebroventricular system of mice with gamma-MSH deficiency restores blood pressure to normal. This salt-sensitive hypertension is accompanied by the development of insulin resistance; the mechanism linking these two consequences of a high-salt diet is not yet known but may involve activation of the sympathetic nervous system.

SUMMARY:

The study of MSH peptides in blood pressure regulation offers a new opportunity to gain insight into the mechanisms underlying salt sensitivity and its link to insulin resistance, and to new therapies.

• Authors: Michael H Humphreys
• Journal: Current opinion in nephrology and hypertension (Curr Opin Nephrol Hypertens) Vol. 16 Issue 1 Pg. 32-8 (Jan 2007) ISSN: 1062-4821 [Print] England
• PMID: 17143069 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Review)

Chemical References

• Receptors, Melanocortin
• Melanocyte-Stimulating Hormones
• Sodium

Topics

• Animals
• Cardiovascular System (metabolism)
• Humans
• Insulin Resistance
• Kidney (metabolism)
• Melanocyte-Stimulating Hormones (physiology)
• Receptors, Melanocortin (physiology)
• Rodentia (metabolism)
• Sodium (metabolism)