Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation
Abstract While a definitive mechanism‐of‐action remains to be identified, recent findings indicate that ghrelin, particularly the unacylated form (UnAG), stimulates skeletal muscle fatty acid oxidation. The biological importance of UnAG‐mediated increases in fat oxidation remains unclear, as UnAG pe...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-09-01
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| Series: | Physiological Reports |
| Subjects: | |
| Online Access: | https://doi.org/10.14814/phy2.15815 |
| _version_ | 1797397495358160896 |
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| author | Evan M. Hoecht Joshua M. Budd Nicole M. Notaro Graham P. Holloway David J. Dyck |
| author_facet | Evan M. Hoecht Joshua M. Budd Nicole M. Notaro Graham P. Holloway David J. Dyck |
| author_sort | Evan M. Hoecht |
| collection | DOAJ |
| description | Abstract While a definitive mechanism‐of‐action remains to be identified, recent findings indicate that ghrelin, particularly the unacylated form (UnAG), stimulates skeletal muscle fatty acid oxidation. The biological importance of UnAG‐mediated increases in fat oxidation remains unclear, as UnAG peaks in the circulation before mealtimes, and decreases rapidly during the postprandial situation before increases in postabsorptive circulating lipids. Therefore, we aimed to determine if the UnAG‐mediated stimulation of fat oxidation would persist long enough to affect the oxidation of meal‐derived fatty acids, and if UnAG stimulated the translocation of fatty acid transporters to the sarcolemma as a mechanism‐of‐action. In isolated soleus muscle strips from male rats, short‐term pre‐treatment with UnAG elicited a persisting stimulus on fatty acid oxidation 2 h after the removal of UnAG. UnAG also caused an immediate phosphorylation of AMPK, but not an increase in plasma membrane FAT/CD36 or FABPpm. There was also no increase in AMPK signaling or increased FAT/CD36 or FABPpm content at the plasma membrane at 2 h which might explain the sustained increase in fatty acid oxidation. These findings confirm UnAG as a stimulator of fatty acid oxidation and provide evidence that UnAG may influence the handling of postprandial lipids. The underlying mechanisms are not known. |
| first_indexed | 2024-03-09T01:11:50Z |
| format | Article |
| id | doaj.art-98a4d608b1fa46beb85233141b8f97f0 |
| institution | Directory Open Access Journal |
| issn | 2051-817X |
| language | English |
| last_indexed | 2024-03-09T01:11:50Z |
| publishDate | 2023-09-01 |
| publisher | Wiley |
| record_format | Article |
| series | Physiological Reports |
| spelling | doaj.art-98a4d608b1fa46beb85233141b8f97f02023-12-11T04:25:44ZengWileyPhysiological Reports2051-817X2023-09-011118n/an/a10.14814/phy2.15815Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocationEvan M. Hoecht0Joshua M. Budd1Nicole M. Notaro2Graham P. Holloway3David J. Dyck4Department of Human Health and Nutritional Sciences University of Guelph Guelph Ontario CanadaDepartment of Human Health and Nutritional Sciences University of Guelph Guelph Ontario CanadaDepartment of Human Health and Nutritional Sciences University of Guelph Guelph Ontario CanadaDepartment of Human Health and Nutritional Sciences University of Guelph Guelph Ontario CanadaDepartment of Human Health and Nutritional Sciences University of Guelph Guelph Ontario CanadaAbstract While a definitive mechanism‐of‐action remains to be identified, recent findings indicate that ghrelin, particularly the unacylated form (UnAG), stimulates skeletal muscle fatty acid oxidation. The biological importance of UnAG‐mediated increases in fat oxidation remains unclear, as UnAG peaks in the circulation before mealtimes, and decreases rapidly during the postprandial situation before increases in postabsorptive circulating lipids. Therefore, we aimed to determine if the UnAG‐mediated stimulation of fat oxidation would persist long enough to affect the oxidation of meal‐derived fatty acids, and if UnAG stimulated the translocation of fatty acid transporters to the sarcolemma as a mechanism‐of‐action. In isolated soleus muscle strips from male rats, short‐term pre‐treatment with UnAG elicited a persisting stimulus on fatty acid oxidation 2 h after the removal of UnAG. UnAG also caused an immediate phosphorylation of AMPK, but not an increase in plasma membrane FAT/CD36 or FABPpm. There was also no increase in AMPK signaling or increased FAT/CD36 or FABPpm content at the plasma membrane at 2 h which might explain the sustained increase in fatty acid oxidation. These findings confirm UnAG as a stimulator of fatty acid oxidation and provide evidence that UnAG may influence the handling of postprandial lipids. The underlying mechanisms are not known.https://doi.org/10.14814/phy2.15815FABPpmFAT/CD36fatty acid oxidationskeletal muscleunacylated ghrelin |
| spellingShingle | Evan M. Hoecht Joshua M. Budd Nicole M. Notaro Graham P. Holloway David J. Dyck Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation Physiological Reports FABPpm FAT/CD36 fatty acid oxidation skeletal muscle unacylated ghrelin |
| title | Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation |
| title_full | Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation |
| title_fullStr | Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation |
| title_full_unstemmed | Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation |
| title_short | Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2–3 hours, but is independent of fatty acid transporter translocation |
| title_sort | stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2 3 hours but is independent of fatty acid transporter translocation |
| topic | FABPpm FAT/CD36 fatty acid oxidation skeletal muscle unacylated ghrelin |
| url | https://doi.org/10.14814/phy2.15815 |
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