September 2016
Volume 57, Issue 12
Open Access
ARVO Annual Meeting Abstract  |   September 2016
Arterial hypertension induces ocular vascular dysfunction in mice with pressure-overload cardiac hypertrophy
Author Affiliations & Notes
  • Shu-Huai Tsai
    Department of Medical Physiology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
  • Wankun Xie
    Department of Ophthalmology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
  • Min Zhao
    Department of Ophthalmology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
  • Robert H Rosa
    Department of Ophthalmology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
  • Travis W Hein
    Department of Ophthalmology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
  • Lih Kuo
    Department of Medical Physiology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
    Department of Ophthalmology, Baylor Scott & White Health, Texas A&M Health Science Center, Temple, Texas, United States
  • Footnotes
    Commercial Relationships   Shu-Huai Tsai, None; Wankun Xie, None; Min Zhao, None; Robert Rosa, None; Travis Hein, None; Lih Kuo, None
  • Footnotes
    Support  Supported by Retina Research Foundation and Kruse Centennial Chair Fund
Investigative Ophthalmology & Visual Science September 2016, Vol.57, 4629. doi:
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    • Get Citation

      Shu-Huai Tsai, Wankun Xie, Min Zhao, Robert H Rosa, Travis W Hein, Lih Kuo; Arterial hypertension induces ocular vascular dysfunction in mice with pressure-overload cardiac hypertrophy. Invest. Ophthalmol. Vis. Sci. 2016;57(12):4629.

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      © ARVO (1962-2015); The Authors (2016-present)

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Abstract

Purpose : The etiology and mechanism of hypertensive retinopathy are not fully understood. Transverse aortic coarctation (TAC) between the two common carotid arteries (CCA) elicits cardiac hypertrophy and 40-50% increase in blood pressure to the right CCA, but its impact on the ocular circulation is unknown. The present study was aimed at using the TAC model to investigate whether arterial hypertension causes retinal injury.

Methods : TAC was performed in mice by banding the aorta between the left CCA and the right brachiocephalic artery, which gives rise to the right CCA. Sham-operated mice served as controls. Blood velocity in CCA and central retinal artery (CRA) was measured by Doppler ultrasound. Ophthalmic arteries were isolated, cannulated and pressurized to 75 cmH2O for functional study. Retinal morphology was examined using fundus imaging, optical coherence tomography, and histology.

Results : Induction of TAC for one month caused left ventricular hypertrophy and dysfunction. Blood velocity in the right CCA was increased by 50% after one week of aortic banding. However, velocity change in the right CRA lagged behind and slowly increased by 50% at 4 weeks post-operation. Blood velocity in the left CCA was decreased by 50% after one week of aortic banding, but the corresponding velocity in the CRA was decreased only by 20% and reached a steady level after 4 weeks of banding. The responses of right (hypertensive) ophthalmic arteries to the endothelium-dependent, nitric oxide-mediated vasodilators acetylcholine and adenosine were significantly reduced and the vasoconstriction to endothelin-1 was increased after 4 weeks of aortic banding. In contrast, the responses of left ophthalmic (hypotensive) arteries to the above agonists were unchanged. There were no marked changes in retinal morphology in both eyes.

Conclusions : Elevated right CCA blood pressure leads to a corresponding increase in flow velocity in both carotid artery and CRA. The elevation of blood pressure and flow for 4 weeks causes ophthalmic vascular dysfunction without altering retinal morphology. The ophthalmic vasomotor function is insensitive to hypotensive insult, and blood flow in the CRA appears to be regulated during hypotension to minimize hypoperfusion. The hypertension-induced ophthalmic vascular changes may lead to dysregulation of ocular blood flow and consequent retinal injury.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

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