Acute effects of empagliflozin on open-loop baroreflex function and urine output in streptozotocin-induced type 1 diabetic rats

Although sympathetic suppression is considered one of the mechanisms for cardioprotection afforded by sodium–glucose cotransporter 2 (SGLT2) inhibitors, whether SGLT2 inhibition acutely modifies sympathetic arterial pressure (AP) regulation remains unclear. We examined the acute effect of an SGLT2 inhibitor, empagliflozin (10 mg/kg), on open-loop baroreflex static characteristics in streptozotocin (STZ)-induced type 1 diabetic and control (CNT) rats (n = 9 each). Empagliflozin significantly increased urine flow [CNT: 25.5 (21.7–31.2) vs. 55.9 (51.0–64.5), STZ: 83.4 (53.7–91.7) vs. 121.2 (57.0–136.0) μL·min⁻¹·kg⁻¹, median (1st–3rd quartiles), P < 0.001 for empagliflozin and STZ]. Empagliflozin decreased the minimum sympathetic nerve activity (SNA) [CNT: 15.7 (6.8–18.4) vs. 10.5 (2.9–19.0), STZ: 36.9 (25.7–54.9) vs. 32.8 (15.1–37.5) %, P = 0.021 for empagliflozin and P = 0.003 for STZ], but did not significantly affect the peripheral arc characteristics assessed by the SNA–AP relationship. Despite the significant increase in urine flow and changes in several baroreflex parameters, empagliflozin preserved the overall sympathetic AP regulation in STZ-induced diabetic rats. The lack of a significant change in the peripheral arc may minimize reflex sympathetic activation, thereby enhancing a cardioprotective benefit of empagliflozin.