© 1999 by European Society of Cardiology
Copyright © 1999, European Society of Cardiology
Protein expression, vascular reactivity and soluble guanylate cyclase activity in mice lacking the endothelial cell nitric oxide synthase: contributions of NOS isoforms to blood pressure and heart rate control
aCardiology Division, Department of Medicine, Emory University School of Medicine and Atlanta Veterans Administration Medical Center, Atlanta, GA, USA
bInstitut für Pharmakologie, Heinrich-Heine-Universität, Düsseldorf, Germany
cDivision of Hypertension and Vascular Research, Henry Ford-Hospital, Detroit, USA
* Corresponding author. Tel.: +49-221-811-2518; fax: +49-221-811-4781. E-mail address: kojda@uni-duesseldorf.de (G. Kojda)
Objective: Both disruption of the endothelial nitric oxide synthase (eNOS) gene and pharmacological inhibition of the NOS produce modest hypertension. It is unclear if and to what extent NOS isoforms other than eNOS contribute to this effect and how loss of one copy of the eNOS gene might impact on vascular reactivity or eNOS protein expression. Methods: We examined protein expression, vascular reactivity, activity of soluble guanylate cyclase, blood pressure and heart rate in mice completely lacking the eNOS gene (eNOS–/–), wild-type mice (eNOS+/+) and mice heterozygotic for the eNOS gene (eNOS+/–). Results: While eNOS–/– mice had mild hypertension and bradycardia, eNOS+/– mice were normotensive. In control mice, oral administration of L-NAME (approximately 100 mg/kg/dayx21 days) increased blood pressure to levels observed in eNOS–/– mice. In eNOS–/– mice, chronic oral administration of L-NAME had no effect on blood pressure, suggesting that inhibition of other NOS isoforms unlikely contribute to hypertension. L-NAME treatment induced bradycardia in both control and eNOS–/– mice, suggesting that both eNOS and other isoforms of NOS might be involved in heart rate control. Studies of aortic rings from eNOS–/– mice revealed a complete lack of endothelium-dependent vascular relaxation in response to acetylcholine and the calcium ionophore A23187 [GenBank] and an increase in sensitivity to phenylephrine, serotonin and nitroglycerin. Aortic rings from eNOS+/– mice demonstrated only minor alterations of responses to nitroglycerin and a normal relaxation to either acetylcholine or A23187 [GenBank] compared to vessels from eNOS+/+. Western analysis demonstrated that eNOS expression was virtually identical between eNOS+/+ and eNOS+/– mice and was absent in eNOS–/– mice. The activity of lung-isolated soluble guanylate cyclase was identical in the three strains of mice. Conclusions: We conclude that loss of one copy of the eNOS gene, as observed in heterozygotic animals, has no effect on vascular reactivity, blood pressure or eNOS protein expression. Isoforms of NOS, other than eNOS are unlikely involved in blood pressure regulation but may participate in heart rate control.
KEYWORDS Endothelial nitric oxide synthase; Gene disruption; Soluble guanylate cyclase; Nitroglycerin; Phenylephrine; Serotonine; Heart rate; Blood pressure
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. Mujoo, V. G. Sharin, N. S. Bryan, J. S. Krumenacker, C. Sloan, S. Parveen, L. E. Nikonoff, A. Y. Kots, and F. Murad Role of nitric oxide signaling components in differentiation of embryonic stem cells into myocardial cells PNAS, December 2, 2008; 105(48): 18924 - 18929. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Daiber, D. G. Harrison, and T. Munzel Doubt about an essential role for constitutive nitric oxide synthase in nitroglycerin-mediated vasodilation PNAS, November 25, 2008; 105(47): E92 - E92. [Full Text] [PDF]
|
|
|
|
 |
|
 E. J. F. Danson, K. S. Mankia, S. Golding, T. Dawson, L. Everatt, S. Cai, K. M. Channon, and D. J. Paterson Impaired regulation of neuronal nitric oxide synthase and heart rate during exercise in mice lacking one nNOS allele J. Physiol., August 1, 2004; 558(3): 963 - 974. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. N Van Vliet, L. L Chafe, and J.-P. Montani Characteristics of 24 h Telemetered Blood Pressure in eNOS-Knockout and C57Bl/6J Control Mice J. Physiol., May 15, 2003; 549(1): 313 - 325. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P B Massion and J-L Balligand Modulation of cardiac contraction, relaxation and rate by the endothelial nitric oxide synthase (eNOS): lessons from genetically modified mice J. Physiol., January 1, 2003; 546(1): 63 - 75. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Schnermann, Y. G Huang, and J. P Briggs Angiotensin II blockade causes acute renal failure in eNOS-deficient mice Journal of Renin-Angiotensin-Aldosterone System, March 1, 2001; 2(1_suppl): S199 - S203. [Abstract] [PDF]
|
|
|
|
|
|
G. Muller-Strahl, K. Kottenberg, H.-G. Zimmer, E. Noack, and G. Kojda Inhibition of nitric oxide synthase augments the positive inotropic effect of nitric oxide donors in the rat heart J. Physiol., January 15, 2000; 522(2): 311 - 320. [Abstract] [Full Text] [PDF]
|
|