| First Author | Shimizu K | Year | 2015 |
| Journal | Am J Pathol | Volume | 185 |
| Issue | 11 | Pages | 3003-10 |
| PubMed ID | 26358220 | Mgi Jnum | J:227010 |
| Mgi Id | MGI:5699510 | Doi | 10.1016/j.ajpath.2015.07.015 |
| Citation | Shimizu K, et al. (2015) Histamine Released from Epidermal Keratinocytes Plays a Role in alpha-Melanocyte-Stimulating Hormone-Induced Itching in Mice. Am J Pathol 185(11):3003-10 |
| abstractText | Sunburn, wound repair, and chronic renal failure with hemodialysis are usually accompanied by both pigmentation and itching. Proopiomelanocortin-derived alpha-melanocyte-stimulating hormone (alpha-MSH) is produced in response to external stimuli, such as UV irradiation, and is involved in cutaneous pigmentation. However, it is unclear whether alpha-MSH is also involved in the itching. We therefore investigated whether alpha-MSH elicited itch-related responses in mice. We found that an intradermal injection of alpha-MSH induced hind-paw scratching, an itch-related response, in mice. The alpha-MSH-induced scratching was inhibited by the mu-opioid receptor antagonist naltrexone and the H1 histamine receptor antagonist terfenadine. In mast cell-deficient mice, alpha-MSH also elicited scratching, which was inhibited by terfenadine. The immunoreactivity for l-histidine decarboxylase, a key enzyme required for the production of histamine, histamine, and the melanocortin 1 and 5 receptors were shown in not only mast cells but also keratinocytes in murine skin. In addition to the expression of l-histidine decarboxylase and melanocortin 1 and 5 receptors, the mouse keratinocyte cell lines (Pam212) also showed immunoreactivity for l-histidine decarboxylase, histamine, and melanocortin 1 and 5 receptors. The application of alpha-MSH induced the release of histamine from Pam212 cells. These findings indicate that alpha-MSH may play an important role in the itching associated with pigmented cutaneous lesions and that the histamine released from keratinocytes is involved in this alpha-MSH-induced itching. |
