科学的に栄養制限(カロリー制限, CR)が, 身体に数々のBenefitをもたらすことが明らかになりつつある。しかし, その作用機序は不明確である。CR時には, 肝臓において脂肪酸からケトン体(3-ヒドロキシ酪酸, アセト酢酸, 3HB)が大量に合成され代替エネルギー源として血流により全身に運搬される。ドライアイに対するCRの効果を, 3HBに着目し, ラットドライアイモデルを用いて検討した。その結果, CR群, 3HB投与群ともに, ドライアイ状態における涙液分泌機能を維持し, CRのドライアイに対する有用性と, その作用に対し3HBが重要な役割を果たすことが示唆された。
Despite calorie restriction (CR) being the oldest and most robust dietary intervention that provides various health benefits, the mechanism underlying this process is still under intensive investigation. D-3-hydroxybutyrate (3HB), a major circulating ketone body, has been proposed to associated with the benefits of CR. In the present study, we explored the possible role of 3HB on the tear secretion by rat dry eye model. Rats were assigned to three groups : AL, ad libitum-fed animals, and CR, intermittent fasting rats, AL+3-HB, 3HB diluted with saline was injected into rat dorsal skin at a dose of 2000 mg/kg/day. Change in tear secretion was significantly suppressed in the CR and AL+3HB compare to the AL. Significant suppression of ROS generation was observed in the CR and AL+3HB compared to that in the AL group. Our findings suggest that increased 3-HB play an important role of tear secretion which can be improved by CR in VDT associated dry eye.
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