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Noninvasive assessment of vascular structure and function in conscious rats based on in vivo imaging of the albino iris. Am J Physiol Regul Integr Comp Physiol 2011 Jun;300(6):R1333-43

Date

03/11/2011

Pubmed ID

21389331

Pubmed Central ID

PMC3119155

DOI

10.1152/ajpregu.00561.2010

Scopus ID

2-s2.0-79958833190 (requires institutional sign-in at Scopus site)   5 Citations

Abstract

Experimental techniques allowing longitudinal studies of vascular disease progression or treatment effects are not readily available for most animal models. Thus, most existing studies are destined to either study individual time points or use large cohorts of animals. Here we describe a noninvasive technique for studying vascular disease that is based on in vivo imaging of the long posterior ciliary artery (LPCA) in the iris of albino rats. Using a slit-lamp biomicroscope, images of the LPCA were taken weekly in conscious normotensive Wistar Kyoto rats (WKY, n = 10) and spontaneously hypertensive rats (SHR, n = 10) for 10 wk. Using imaging software, we found that lumen diameter was significantly smaller and the wall-to-lumen (W/L) ratio larger in SHR than in WKY. Wall thickness was not different. Blood pressure correlated with the W/L ratio. Histology of the abdominal aorta also revealed a smaller lumen diameter and greater W/L ratio in SHR compared with WKY. Corneal application of the muscarinic receptor agonist pilocarpine elicited a dose-dependent vasodilation of the LPCA that could be antagonized by inhibition of nitric oxide synthase, suggesting that the pilocarpine response is mainly mediated by endothelium-derived nitric oxide. Consistent with endothelial dysfunction in SHR, pilocarpine-induced vasodilation was greater in WKY rats than in SHR. These findings indicate that in vivo imaging of the LPCA allows assessment of several structural and functional vascular parameters in conscious rats and that the LPCA responds to disease insults and pharmacologic treatments in a fashion that will make it a useful model for further studies.

Author List

Stauss HM, Rarick KR, Leick KM, Burkle JW, Rotella DL, Anderson MG

Author

Kevin Richard Rarick PhD Assistant Professor in the Pediatrics department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Blood Pressure
Ciliary Arteries
Consciousness
Endothelium, Vascular
Feasibility Studies
Iris
Male
Microscopy
Models, Animal
Papaverine
Pilocarpine
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Rats, Mutant Strains
Rats, Sprague-Dawley
Vasodilation
Vasodilator Agents