Fluid shear stress-induced nitric oxide production in human cavernosal endothelial cells: inhibition by hyperglycaemia.
OBJECTIVE
To investigate whether fluid shear stress (FSS) induces endothelial nitric oxide synthase (eNOS) activity and NO production in isolated human corpus cavernosal endothelial cells (HCCECs), and whether this response is altered during hyperglycaemia in vitro, as haemodynamic signalling during penile erection induces eNOS-mediated NO production in vivo.


METHODS
ECs were cultured from HCC and characterized by the uptake of acetylated low-density lipoprotein and the expression of von Willebrand factor, VE-cadherin, CD31 and eNOS. HCCECs were exposed to FSS (1.2 Pa (12 dynes/cm2), 5 min) using a cone-and-plate viscometer in the presence or absence of high glucose (30 mm, 48 h). The phosphorylation of ser1177 on eNOS and total eNOS protein expression after FSS was examined by Western blot. NO in the conditioned media was assessed by measuring nitrate and nitrite levels.


RESULTS
Compared to static conditions, FSS induced a significant increase in the phosphorylation of eNOS on ser1177 in HCCECs, and the release of NO to the conditioned media. Treatment of HCCECs with high glucose levels did not alter the ratio FSS-induced phosphorylated eNOS/total eNOS, but did result in the down-regulation of total eNOS and significantly attenuated FSS-induced NO release.


CONCLUSIONS
These in vitro data suggest that FSS contributes to eNOS activation and NO release in HCCECs, and supports in vivo reports suggesting a role for haemodynamic signalling in the erectile response. Treatment with high glucose levels prevented FSS-induced NO release, suggesting a mechanism that may contribute to decreased erectile function associated with diabetes.
Wessells
Hunter
H
Department of Urology, University of Washington School of Medicine and Harborview Medical Center, Seattle, WA 98104-2499, USA. wessells@u.washington.edu
Teal
Thomas H
TH
Engel
Karen
K
Sullivan
Christopher J
CJ
Gallis
Byron
B
Tran
Khoa B
KB
Chitaley
Kanchan
K
D015536:Down-Regulation; D042783:Endothelial Cells / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010410:Penile Erection / Q000502:physiology*; D010413:Penis / Q000098:blood supply / Q000378:metabolism*; D012039:Regional Blood Flow / Q000502:physiology; D013314:Stress, Mechanical
D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III