title: Canine epidermal lipid sampling by skin scrub revealed variations between different body sites and normal and atopic dogs.
abstract: BACKGROUND
  Previously, we evaluated a minimally invasive epidermal lipid sampling method called skin scrub, which achieved reproducible and comparable results to skin scraping. The present study aimed at investigating regional variations in canine epidermal lipid composition using the skin scrub technique and its suitability for collecting skin lipids in dogs suffering from certain skin diseases. Eight different body sites (5 highly and 3 lowly predisposed for atopic lesions) were sampled by skin scrub in 8 control dogs with normal skin. Additionally, lesional and non-lesional skin was sampled from 12 atopic dogs and 4 dogs with other skin diseases by skin scrub. Lipid fractions were separated by high performance thin layer chromatography and analysed densitometrically.
  
  
  RESULTS
  No significant differences in total lipid content were found among the body sites tested in the control dogs. However, the pinna, lip and caudal back contained significantly lower concentrations of ceramides, whereas the palmar metacarpus and the axillary region contained significantly higher amounts of ceramides and cholesterol than most other body sites. The amount of total lipids and ceramides including all ceramide classes were significantly lower in both lesional and non-lesional skin of atopic dogs compared to normal skin, with the reduction being more pronounced in lesional skin. The sampling by skin scrub was relatively painless and caused only slight erythema at the sampled areas but no oedema. Histological examinations of skin biopsies at 2 skin scrubbed areas revealed a potential lipid extraction from the transition zone between stratum corneum and granulosum.
  
  
  CONCLUSIONS
  The present study revealed regional variations in the epidermal lipid and ceramide composition in dogs without skin abnormalities but no connection between lipid composition and predilection sites for canine atopic dermatitis lesions. The skin scrub technique proved to be a practicable sampling method for canine epidermal lipids, revealed satisfying results regarding alterations of skin lipid composition in canine atopic dermatitis and might be suitable for epidermal lipid investigations of further canine skin diseases. Although the ceramide composition should be unaffected by the deeper lipid sampling of skin scrub compared to other sampling methods, further studies are required to determine methodological differences.
authors.forename: Mandy
authors.initials: M
authors.lastname: Angelbeck-Schulze
authors.affiliation: Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, Buenteweg 9, Hanover 30559, Germany. reinhard.mischke@tiho-hannover.de.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Mischke
authors.forename: Karl
authors.initials: K
authors.lastname: Rohn
authors.forename: Marion
authors.initials: M
authors.lastname: Hewicker-Trautwein
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Naim
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bäumer
mesh_terms: D000818:Animals; D002518:Ceramides / Q000737:chemistry / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000378:metabolism / Q000662:veterinary*; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D004817:Epidermis / Q000737:chemistry*; D050356:Lipid Metabolism / Q000502:physiology*; D008055:Lipids / Q000737:chemistry*; D012867:Skin / Q000737:chemistry / Q000378:metabolism; D013048:Specimen Handling / Q000379:methods / Q000662:veterinary*
chemical_list: D002518:Ceramides; D008055:Lipids