Neuropeptides in the pathogenesis of obesity-associated benign acanthosis nigricans.
The association of acanthosis nigricans with pituitary tumors and insulin-resistant diabetes suggests that a pituitary peptide may promote papillomatosis and acanthosis characteristic of acanthosis nigricans. Although such a peptide has not been isolated, it may derive by sequential cleavage from the 31,000-dalton precursor peptide to ACTH and beta-lipotropin (beta-LPH). In order to evaluate the role of pituitary peptides in the pathogenesis of acanthosis nigricans, we compared plasma levels of beta-endorphin (beta-EP) and ACTH in plasma of 8 fasting patients with obesity-associated benign acanthosis nigricans and 7 fasting normal controls utilizing sensitive radioimmunoassay procedures. Mean plasma beta-EP levels for the acanthosis nigricans and control subjects were not significantly different (90 pg/ml vs. 140 pg/ml), nor was any significant difference observed between plasma ACTH levels of the 2 groups (42.3 and 31.2 pg/ml, respectively.) Our data indicate that plasma levels of the pituitary-derived peptides ACTH and beta-EP are not increased in obesity-associated benign acanthosis nigricans, and suggest that its proposed hormonal mediator might originate independently from the large peptide precursor of ACTH, beta-LPH and their fragments.
D000052:Acanthosis Nigricans / Q000209:etiology* / Q000503:physiopathology; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D002648:Child; D004723:Endorphins / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D010902:Pituitary Gland / Q000503:physiopathology; D012016:Reference Values; D001615:beta-Endorphin
D004723:Endorphins; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone