title: Chick chorioallantoic membrane as an in vivo model to study vasoreactivity: characterization of development-dependent hyperemia induced by epoxyeicosatrienoic acids (EETs).
abstract: Shell-less culture of chick chorioallantoic membrane (CAM) of developing chicken embryos is a useful model to evaluate the effects of vascular agents. We assessed the response of CAM vessels to epoxyeicosatrienoic acids (EETs), derivatives of the essential fatty acid arachidonic acid, that have a number of important biological functions, including dilation of microvessels in the coronary, cerebral, renal, and mesenteric circulations. Three of four regioisomers of EETs, 14,15-, 11,12-, and 8,9-EET, induced a characteristic dose-dependent acute hyperemia within 4 min after application on 10-day-old CAMs. This response was marked in early stages of development (between days 8 and 10), but the frequency and intensity of the response were reduced after 11 days of development. Histological examination demonstrated that the hyperemia was not due to extravasation of erythrocytes. However, many capillaries were distended and contained densely packed erythrocytes as compared to uniformly arranged vessels and erythrocytes in untreated CAMs. Transmission electron microscopy showed the basal laminae surrounding capillaries remained intact, similar to those in vehicle-treated or untreated CAM tissue. The hyperemia was specific to EETs since we did not observe it to be induced by other vasodilators such as nitric oxide or prostacyclin. In conclusion, we report a novel vascular response to EETs using the CAM as an in vivo model. These lipids specifically distend a subset of capillaries in a dose- and development-dependent manner.
authors.affiliation: Cardiovascular Center, Pulmonary and Critical Care Division, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
authors.forename: Laurel K
authors.initials: LK
authors.lastname: Dunn
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Gruenloh
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Dunn
authors.forename: D Sudarshan
authors.initials: DS
authors.lastname: Reddy
authors.forename: John R
authors.initials: JR
authors.lastname: Falck
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Jacobs
authors.forename: Meetha
authors.initials: M
authors.lastname: Medhora
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives*; D000818:Animals; D002196:Capillaries / Q000187:drug effects / Q000196:embryology / Q000473:pathology; D002642:Chick Embryo; D049033:Chorioallantoic Membrane / Q000098:blood supply*; D046508:Culture Techniques; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006940:Hyperemia / Q000139:chemically induced / Q000196:embryology* / Q000473:pathology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D020030:Nitric Oxide Donors / Q000494:pharmacology; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology; D014817:Vitelline Membrane / Q000098:blood supply
chemical_list: D020030:Nitric Oxide Donors; D014665:Vasodilator Agents; C046783:11,12-epoxy-5,8,14-eicosatrienoic acid; C050715:8,9-epoxyeicosatrienoic acid; C046782:14,15-epoxy-5,8,11-eicosatrienoic acid; D015126:8,11,14-Eicosatrienoic Acid