UTL Repository >
Faculdade de Medicina Veterinária >
Departamento de Clínica >
DC - Artigos de revista >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10400.5/253

Title: Intrinsic vasomotricity and adrenergic effects in a model of isolated rabbit eye
Authors: Delgado, Esmeralda
Marques-Neves, Carlos
Rocha, Isabel
Sales-Luis, José
Silva-Carvalho, Luís
Keywords: Adrenergic drugs
Isolated perfused rabbit eye
Spontaneous vasomotion
Issue Date: 5-Dec-2008
Publisher: Blackwell Publishing
Abstract: Purpose: We aimed to investigate the responsiveness of the ocular arteries to adrenergic drugs in a model of perfused isolated rabbit eye. Methods: Rabbit external ophthalmic arteries (n = 15) in a head-mounted preparation were cannulated and the retinal and uveal vasculature perfused at a constant flow with warmed tyrode. The three-way polypropylene catheter was further connected to a pressure transducer and intraluminal pressure was taken as a measure of vascular resistance. Effects of intra-arterial injections of phenylephrine (group A, n = 5), prazosin (group B, n = 5) and phentolamine (group C, n = 5) on the recorded pressure were obtained. Student’s paired-t test and one-way analysis of variance were used for statistical analysis (p < 0.05). Results: Intrinsic vasomotricity was observed in all preparations prior to any drug administration. Phenylephrine produced an increase in total vascular resistance. Intrinsic vasomotricity became more evident, showing a lower frequency but higher amplitude of oscillations. Evoked vasomotor responses with phenylephrine (250 lg ⁄ ml) were inhibited by intra-arterial administration of the selective a1-adrenergic antagonist, prazosin (0.5 mg⁄ ml), as well as the non-selective a-adrenergic antagonist phentolamine (6 mg⁄ ml). Conclusions: Rabbit external ophthalmic arteries showed spontaneous contractions under constant perfusion. Phenylephrine elicited a vasoconstrictor response that was inhibited by adrenergic antagonists. In addition, the intrinsic vasomotricity was enhanced by phenylephrine and blocked by adrenergic antagonists. These results show that under in vitro perfusion the territory presents similar responses to adrenergic drugs to those observed in in vivo models and also provides evidence of myogenic autoregulatory properties in the rabbit ophthalmic artery and ⁄ or choroid
Description: Título da Revista: Acta Ophthalmologica Scandinavica
URI: http://hdl.handle.net/10400.5/253
Appears in Collections:DC - Artigos de revista

Files in This Item:

File Description SizeFormat
Artigo_Intrinsic vasomotricity and adrenergic effects in a model of isolated rabbit eye.pdf215.84 kBAdobe PDFView/Open
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpaceOrkut
Formato BibTex mendeley Endnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Estamos no RCAAP Governo Português separator Ministério da Educação e Ciência   Fundação para a Ciência e a Tecnologia

Financiado por: