Assessment of Ketamine's Influence on In Vitro Angiogenesis

Abstract

Objective: Angiogenesis is associated with angiogenic therapy and wound healing processes. It is important for anesthesiologists to understand the effects of perioperative and long-term use of anesthetics on angiogenesis. This study aimed to determine the effects of ketamine on in vitro angiogenesis: the proliferation of human umbilical vein endothelial cells (HUVEC) and normal human diploid fibroblasts (NHDF), HUVEC migration, and in vitro capillary tube formation in cocultured HUVEC and NHDF.

Methods: The effects of ketamine at concentrations of 1, 10, and 50 µM on the proliferation of HUVEC and NHDF for 48 hours were determined by using a water-soluble tetrazolium salt reagent. Quantitation of migration for 22 hours was achieved by measuring the fluorescence of migrating HUVEC exposed to ketamine using an angiogenesis system. The effects of ketamine on capillary tube formation with or without vascular endothelial growth factor (VEGF) were investigated in cocultured HUVEC and NHDF incubated for 3 and 10 days.

Results: Ketamine did not show any enhancing or suppressive effects on the in vitro proliferation of HUVEC and NHDF, HUVEC migration, or capillary tube formation in cocultured HUVEC and NHDF for either 3 or 10 days in the presence or absence of VEGF.

Conclusion: Ketamine had no effects on in vitro angiogenesis using cultured HUVEC and NHDF. Ketamine can potentially be used as an anesthetic agent with no influence on angiogenesis.

Keywords: Angiogenesis; Cell Proliferation; Human umbilical vein endothelial cells; Ketamine; Migration.

Figure 1.

Effects of Ketamine on Cell Proliferation HUVEC (A) and NHDF (B) were stimulated with ketamine at 1, 10, and 50 µM (K1, K10, and K50, respectively; C, control) and incubated for 48 hours. Ketamine did not significantly influence HUVEC and NHDF proliferation at 48 hours. Abbreviations: HUVEC, human umbilical vein endothelial cells; NHDF, normal human diploid fibroblasts.

Figure 2.

Effects of Ketamine on Endothelial Cell Migration Control: Fluorescence intensity of calcein AM in HUVEC incubated with medium containing 2% FBS (FBS+) or no FBS (FBS-) for 22 hours. Ketamine: Fluorescence intensity of calcein AM in HUVEC stimulated by 50 µM ketamine with FBS- or FBS+ for 22 hours. Ketamine did not significantly influence migration in non-stimulated or FBS-stimulated HUVEC. * indicates P < .001 compared with the migration of HUVEC in Control group without FBS. Abbreviations: FBS, fetal bovine serum; HUVEC, human umbilical vein endothelial cells.

Figure 3.

Effects of Ketamine on Capillary Tube Formation After Incubation for 3 Days We assessed the area (A) and length (B) of tubules and the numbers of joints (C) and paths (D) to determine the effects of ketamine on in vitro capillary tube formation. VEGF significantly stimulated in vitro capillary tube formation in all aspects. Ketamine (50 µM) did not significantly influence any of the components of in vitro capillary tube formation stimulated with or without VEGF. Data are expressed as mean ± SD; * indicates P < .001 compared with no stimulation. Abbreviation: VEGF, vascular endothelial growth factor.

Figure 4.

Effects of Ketamine on Capillary Tube Formation After Incubation for 10 Days We assessed the area (A) and length (B) of the tubules and the number of joints (C) and paths (D) to determine the effects of ketamine on in vitro capillary tube formation. VEGF significantly stimulated in vitro capillary tube formation in all aspects, while suramin significantly inhibited all aspects with VEGF. Ketamine (10, 50 µM) did not significantly influence any of the components of in vitro capillary tube formation with or without VEGF. Data are expressed as mean ± SD; * indicates P < .001 compared with no stimulation; § indicates P < .001 compared with VEGF (positive control). Abbreviation: VEGF, vascular endothelial growth factor.