Phloridzin inhibits high K+-induced contraction via the inhibition of sodium: glucose cotransporter 1 in rat ileum

The Journal of Veterinary Medical Science

Noriyasu SASAKI¹  Kazumasa SHIMIZU²  Tsuyoshi TAJIMA²  Hidenori KANDA²  Takeharu KANEDA²  Norimoto URAKAWA²  Akira KAWAGUCHI²  Hiroetsu SUZUKI³ 

[1] Laboratory of Veterinary Biochemistry Nippon Veterinary and Life Science University, Kyonan-cho 1-chome, Musashino, Tokyo 180-862, Japan;Laboratory of Veterinary Pharmacology Nippon Veterinary and Life Science University, Kyonan-cho 1-chome, Musashino, Tokyo 180-862, Japan;Laboratory of Veterinary Physiology Nippon Veterinary and Life Science University, Kyonan-cho 1-chome, Musashino, Tokyo 180-862, Japan

关键词: glucose uptake;    ileum;    phloridzin;    SGLT1;    smooth muscle;   

DOI  :  10.1292/jvms.16-0560

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

Recent studies have shown that phloridzin, an inhibitor of sodium–glucose cotransporter (SGLT), strongly decreases high K+-induced contraction in phasic muscle, such as tenia coli, but slightly affects tonic muscle, such as trachea . In this study, we examined the inhibitory mechanism of phloridzin on high K+-induced muscle contraction in rat ileum, a phasic muscle. Phloridzin inhibited the high K+-induced contraction in the ileum and the aorta, and the relaxing effect of phloridzin at 1 mM in the ileum was approximately five-fold more potent than that in the aorta. The expression of SGLT1 mRNA in the ileum was higher than that of the aorta. Phloridzin significantly inhibited NADH/NAD ratio and phosphocreatine (PCr) content in the ileum; however, application of pyruvate recovered the inhibition of contraction and PCr content, but had no effect on ratio of NADH/NAD. High K+ increased 2-(N (7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxyglucose (2-NBDG) uptake in ileal smooth muscle cells, and phloridzin inhibited the increase in a concentration-dependent manner. These results suggest that phloridzin inhibits high K+-induced contraction because of the inhibition of energy metabolism via the inhibition of SGLT1.

【 授权许可】

Unknown