title: The chick chorioallantoic membrane imaging method as a platform to evaluate vasoactivity and assess irritancy of compounds.
abstract: OBJECTIVE
  To determine if the chick chorioallantoic membrane (CAM) is a potential alternative that is capable of screening test substances for vasoactivity in terms of vessel diameter changes. The CAM was also evaluated as a tool for irritancy screening.
  
  
  METHODS
  Visual assessment of the CAM for irritancy after the application of the test substance or solvent to its surface was made. An imaging based-in-vivo CAM model was developed by imaging CAM blood vessels in a pre-defined area using a semi-automatic image processing and analysis technique to measure blood vessel diameters. Solvents and drugs such as 70% v/v ethanol, normal saline, 5% w/v glucose monohydrate, glycerin, glucagon, N-methylpyrrolidone, nicotine, glyceryl trinitrate, glucagon, propranolol and caffeine were tested on the CAM.
  
  
  RESULTS
  Propranolol, nicotine and glycerin were irritants on CAM. Changes in the diameters of fine blood vessels were accurately measured by high resolution image analysis. Vasoconstriction was seen with 70% v/v ethanol while vasodilation was displayed with glucagon and caffeine. The results reflected expected trends with evidence of feedback mechanisms ensuring homeostasis.
  
  
  CONCLUSIONS
  The CAM model can be applied to assess pharmaceutical and cosmetic formulations in early development work to gain useful insights to potential irritancy and biological effects of components and formulations.
authors: Department of Pharmacy, National University of Singapore, Singapore.
authors: Stephanie L M
authors: SL
authors: Tay
authors: Paul W S
authors: PW
authors: Heng
authors: Lai Wah
authors: LW
authors: Chan
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000033:anatomy & histology / Q000187:drug effects*; D002110:Caffeine / Q000494:pharmacology; D002642:Chick Embryo; D049033:Chorioallantoic Membrane / Q000098:blood supply / Q000187:drug effects*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005934:Glucagon / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D006706:Homeostasis; D007509:Irritants / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D012997:Solvents / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000009:adverse effects / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000009:adverse effects / Q000494:pharmacology*
chemical_list: D007509:Irritants; D012997:Solvents; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D002110:Caffeine; D009538:Nicotine; D005934:Glucagon; D011433:Propranolol; D005990:Glycerol