Agouti-related maturation and tissue distribution of alpha-melanocyte stimulating hormone in wild-type (A(wJ)/A(wJ)) and mutant (A(y)/a, a/a) mice

Because of ectopic overproduction of agouti protein, yellow alleles (A(y) a nd A(vy)) Of th, murine agouti gene may secondarily modulate the synthesis, maturation (i.e., acetylation), and/or tissue deployment of alpha-Melanocy te Stimulating Hormone (MSH). We used HPLC to test the hypothesis that A(y) /a mice exhibit altered concentrations of desacetyl-, monoacetyl-, and diac etyl-alpha-MSH in pituitaries, sera, and telogen hair bulbs when compared t o black (a/a) mice. We also used RW to measure total MSH in those same tiss ues of A(y)/a, a/a, and white-bellied agouti (A(wJ)/A(wJ)) mice (Strain C57 BL/6J). We found no evidence that A(y)/a mice possessed an imbalance of des -, mono-, and diacetylated alpha-MSH species. However, radioimmunoassay (RW ) analyses of total MSH suggest that wildtype agouti mice (A(wJ)/A(wJ)) exh ibited significantly decreased (P < 0.05) tissue levels of total alpha-MSH in pituitaries, sera, and regenerating hair bulbs when compared to those of mutant A(y)/a and a/a mice.