| Autor: |
Yoshihiro eNishi, Hiroharu eMifune, Akira eYabuki, Yuji eTajiri, Rumiko eHirata, Eiichiro eTanaka, Hiroshi eHosoda, Kenji eKangawa, Masayasu eKojima |
| Jazyk: |
angličtina |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
Frontiers in Endocrinology, Vol 4 (2013) |
| Druh dokumentu: |
article |
| ISSN: |
1664-2392 |
| DOI: |
10.3389/fendo.2013.00084 |
| Popis: |
Background: The enzyme ghrelin O-acyltransferase (GOAT) catalyzes the acylation of ghrelin. The molecular form of GOAT, together with its reaction in vitro, has been reported previously. However, the sub-cellular processes governing the acylation of ghrelin remain to be elucidated.Methods: Double immunoelectron microscopy was used to examine changes in the relative proportions of secretory granules containing n-octanoyl ghrelin (C8-ghrelin) or n-decanoyl ghrelin (C10-ghrelin) in ghrelin-producing cells of mouse stomachs. The dynamics of C8-type (possessing C8-ghrelin exclusively), C10-type (possessing C10-ghrelin only) and mixed-type secretory granules (possessing both C8- and C10-ghrelin) were investigated after fasting for 48h or after two weeks’ feeding with chow containing glyceryl-tri-octanoate (C8-MCT) or glyceryl-tri-decanoate (C10-MCT). The dynamics of C8- or C10-ghrelin immunoreactivity (ir-C8- or ir-C10-ghrelin) within the mixed-type granules were also investigated.Results: Immunoelectron microscopic analysis revealed the co-existence of C8- and C10-ghrelin within the same secretory granules (mixed-type) in ghrelin-producing cells. Compared to control mice fed standard chow, the ratio of C10-type secretory granules increased significantly after ingestion of C10-MCT, whereas that of C8-type granules declined significantly under the same treatment. After ingestion of C8-MCT, the proportion of C8-type secretory granules increased significantly. Within the mixed-type granules the ratio of ir-C10-ghrelin increased significantly and that of ir-C8-ghrelin decreased significantly upon fasting. Conclusions: These findings confirmed that C10-ghrelin, another acyl-form of active ghrelin, is stored within the same secretory granules as C8-ghrelin, and suggested that the types of medium-chain acyl-molecules surrounding and available to the ghrelin-GOAT system may affect the physiological processes of ghrelin acylation. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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