Sexually Dimorphic Phenotype of Arteriolar Responsiveness to Shear Stress in Soluble Epoxide Hydrolase-Knockout Mice

Authors

Jun Qin, Department of Physiology, New York Medical College, Valhalla, New York; Renji Hospital, Shanghai Jiaotong University School of Medicine, People's Republic of China;
Sharath Kandhi, Department of Physiology, New York Medical College, Valhalla, New York;
Ghezal Froogh, Department of Physiology, New York Medical College, Valhalla, New York;
Houli Jiang, Department of Pharmacology, New York Medical College, Valhalla, New York;
Meng Luo, Renji Hospital, Shanghai Jiaotong University School of Medicine, People's Republic of China; Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, People's Republic of China.
Dong Sun, Department of Physiology, New York Medical College, Valhalla, New York;
An Huang, Department of Physiology, New York Medical College, Valhalla, New York; an_huang@nymc.edu.

Author Type(s)

Faculty

DOI

10.1152/ajpheart.00568.2015

Journal Title

American Journal of Physiology. Heart and Circulatory Physiology

First Page

H1860

Last Page

6

Document Type

Article

Publication Date

12-1-2015

Keywords

arterioles, epoxyeicosatrienoic acids, flow/shear stress-induced vasodilation, sex, soluble epoxide hydrolase

Disciplines

Medicine and Health Sciences

Abstract

We hypothesized that potentiating the bioavailability of endothelial epoxyeicosatrienoic acids (EETs) via deletion of the gene for soluble epoxide hydrolase (sEH), or downregulation of sEH expression, enhances flow/shear stress-induced dilator responses (FID) of arterioles. With the use of male (M) and female (F) wild-type (WT) and sEH-knockout (KO) mice, isolated gracilis muscle arterioles were cannulated and pressurized at 80 mmHg. Basal tone and increases in diameter of arterioles as a function of perfusate flow (5, 10, 15, 20, and 25 μl/min) were recorded. The magnitude of FID was significantly smaller and associated with a greater arteriolar tone in M-WT than F-WT mice, revealing a sex difference in FID. This sex difference was abolished by deletion of the sEH gene, as evidenced by an enhanced FID in M-KO mice to a level comparable with those observed in F-KO and F-WT mice. These three groups of mice coincidentally exhibited an increased endothelial sensitivity to shear stress (smaller WSS50) and were hypotensive. Endothelial EETs participated in the mediation of enhanced FID in M-KO, F-KO, and F-WT mice, without effects on FID of M-WT mice. Protein expression of sEH was downregulated by approximately fourfold in vessels of F-WT compared with M-WT mice, paralleled with greater vascular EET levels that were statistically comparable with those observed in both male and female sEH-KO mice. In conclusion, sex-different regulation of sEH accounts for sex differences in flow-mediated dilation of microvessels in gonadally intact mice.

Recommended Citation

Qin, J., Kandhi, S., Froogh, G., Jiang, H., Luo, M., Sun, D., & Huang, A. (2015). Sexually Dimorphic Phenotype of Arteriolar Responsiveness to Shear Stress in Soluble Epoxide Hydrolase-Knockout Mice. American Journal of Physiology. Heart and Circulatory Physiology, 309 (11), H1860-6. https://doi.org/10.1152/ajpheart.00568.2015