Moroi Masao, Kubota Tetsuya
*Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan; and †Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan.
J Cardiovasc Pharmacol. 2015 Aug;66(2):159-64. doi: 10.1097/FJC.0000000000000258.
Glucagon-like peptide-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are antidiabetic agents; however, their mechanisms of action are different. GLP-1R and DPP-4 are also expressed in the renal proximal tubular brush border, where they regulate Na reabsorption. We investigated whether the DPP-4 inhibitor, teneligliptin, has diuretic and natriuretic effects and whether these are associated with the stimulation of the GLP-1R in rats. Oral administration of teneligliptin resulted in a reduction of plasma DPP-4 activity over 6 hours, as well as an induction of diuresis and natriuresis. Although teneligliptin did not change the increase in blood glucose levels by glucose loading, percentage of urine volume and Na/K ratio with teneligliptin to vehicle were augmented by glucose loading. Peak levels of plasma GLP-1 did not change after oral administration of teneligliptin when glucose was not loaded but increased at least 2-fold with glucose loading. Furthermore, the natriuretic effect of teneligliptin was inhibited by the GLP-1R antagonist, exendin9-39, whereas the diuresis was not affected. These results suggest that the mechanism of natriuresis was different from that of diuresis, and the natriuresis is associated with the stimulation of GLP-1R. There may be mechanistic differences in DPP-4 inhibition between diuresis and natriuresis.
胰高血糖素样肽-1受体(GLP-1R)激动剂和二肽基肽酶-4(DPP-4)抑制剂是抗糖尿病药物;然而,它们的作用机制不同。GLP-1R和DPP-4也表达于肾近端小管刷状缘,在那里它们调节钠的重吸收。我们研究了DPP-4抑制剂替格列汀是否具有利尿和利钠作用,以及这些作用是否与大鼠GLP-1R的刺激有关。口服替格列汀导致血浆DPP-4活性在6小时内降低,同时诱导利尿和利钠。尽管替格列汀不会改变葡萄糖负荷引起的血糖水平升高,但葡萄糖负荷会增加替格列汀组与溶剂对照组相比的尿量百分比和钠/钾比值。在未给予葡萄糖负荷时,口服替格列汀后血浆GLP-1的峰值水平没有变化,但在给予葡萄糖负荷时至少增加了2倍。此外,GLP-1R拮抗剂艾塞那肽9-39可抑制替格列汀的利钠作用,而对利尿作用无影响。这些结果表明,利钠机制与利尿机制不同,利钠作用与GLP-1R的刺激有关。利尿和利钠过程中DPP-4抑制的机制可能存在差异。