ABC transporters in the eyes of dogs and implications in drug therapy.
OBJECTIVE
The current study aims to quantifies the level of expression of selected adenosine triphosphate-binding cassette (ABC) efflux transporters and the major drug metabolizing enzyme CYP450 3A12 in the eyes of dogs.


METHODS
The levels of expression were quantified by real-time polymerase chain reaction in the cornea, conjunctiva and retinal tissue.


RESULTS
ABCB1 mRNA is present at high levels in all analysed tissues. ABCC1, ABCC3 and ABCC4 are expressed predominantly in the conjunctiva and at very low levels in the cornea. ABCC2 could not be detected in any of the tissues. CYP3A12 expression was found in the retina and conjunctiva.


CONCLUSIONS
These data are presented for the first time for ocular tissues of dogs of different breeds and a comparison with other species such as humans and rabbits demonstrated remarkable species differences, which might be of clinical relevance. The impact of these findings is discussed with reference to topical and systemic drug application in the treatment of ophthalmological diseases.
Department of Pharmacology, Physiology of Animals and Physiological Chemistry, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria. haritova@uni-sz.bg
Aneliya M
AM
Haritova
Svetozar Z
SZ
Krastev
Regiane R
RR
Santos
Johannes A
JA
Schrickx
Johanna
J
Fink-Gremmels
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D003228:Conjunctiva / Q000502:physiology; D003315:Cornea / Q000502:physiology; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D004285:Dogs; D005128:Eye Diseases / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary; D005260:Female; D015870:Gene Expression / Q000502:physiology; D008297:Male; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000502:physiology
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D003577:Cytochrome P-450 Enzyme System; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger; C000715087:ABCC2 protein, human; C114462:multidrug resistance-associated protein 3; C475779:cytochrome P-450 CYP3A12 (canine)