Pituitary pigmentary hormones. Relationship of melanocyte-stimulating hormone to lipotropic hormone
J. D. Brown and R. P. Doe
Pituitary control of pigmentation has known for more than 60 years. Since
1969, beta-melanocyte-stimulating hormone (beta-MSH) has been accepted as
the main pituitary pigmentary hormone in man. Its "constant companionship"
with adrenocorticotrophic hormone (ACTH) has also been repeatedly
demonstrated. Current investigations challenge both of these concepts.
Human beta-MSH immunoreactivity has been shown to be actually due to
beta-lipotropic hormone (beta-LPH), a larger molecule that within itself
contains the entire amino acid sequence of beta-MSH. Human beta-MSH does
not exist in vivo; it is merely an extraction artifact formed by enzymatic
degradation of beta-LPH. It would appear likely that beta-LPH, not
beta-MSH, is the constant companion of ACTH.