title: Tear Production After Bilateral Main Lacrimal Gland Resection in Rabbits.
abstract: OBJECTIVE
  This study reports tear compensation observed in rabbits with bilateral resection of main lacrimal gland (LG) and explored the potential mechanisms.
  
  
  METHODS
  Dry eye conditions were created by resection of nictitating membrane (NM), Harderian gland (HG), and main LG in eight (16 eyes) male New Zealand White rabbits. In addition to Schirmer test, Periodic acid-Schiff (PAS) staining, and ocular surface staining with fluorescein and rose Bengal, conjunctival impression cytology was employed before and up to 4 months after excision (AE). Using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), expression of inflammatory biomarkers (IL-1β, TNF-α, and matrix metalloproteinase-9) were monitored. Further, involvement of ionic and water transporters were investigated in conjunctival epithelium.
  
  
  RESULTS
  Significant dry eye phenotypes in rabbits were observed 1 month AE, which corroborated with elevated biomarker mRNA expression. However, Schirmer test score and goblet cell numbers never decreased AE in conjunctival epithelium. Moreover, ocular surface staining, and biomarker expression declined to baseline in over 4 months AE. No upregulation was observed of the following conjunctival ionic transporters: cystic fibrosis transmembrane conductance regulator, sodium potassium chloride cotransporters, sodium potassium ATPase, and epithelial sodium channels. Instead, aquaporin (AQP) 4 and AQP5 were upregulated. Immunolocalization and immune blotting of AQP4 was demonstrated in rabbit conjunctival epithelium.
  
  
  CONCLUSIONS
  In the absence of NM, HG, and main LG in rabbits, tear secretion was not decreased and significant improvement of dry eye phenotypes observed with time AE. Conjunctival AQPs are possibly involved in a compensatory tear fluid production.
authors.affiliation: Department of Ophthalmology and Vision Science University of Arizona College of Medicine, Tucson, Arizona, United States.
authors.forename: Dhruva
authors.initials: D
authors.lastname: Bhattacharya
authors.affiliation: Department of Ophthalmology and Vision Science University of Arizona College of Medicine, Tucson, Arizona, United States 2Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University, Ke.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ning
authors.affiliation: Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University, Key Lens Research Laboratory of Liaoning Province, Shenyang, China.
authors.forename: Fangkun
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology and Vision Science University of Arizona College of Medicine, Tucson, Arizona, United States.
authors.forename: William
authors.initials: W
authors.lastname: Stevenson
authors.affiliation: Department of Ophthalmology and Vision Science University of Arizona College of Medicine, Tucson, Arizona, United States.
authors.forename: Rongji
authors.initials: R
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University, Key Lens Research Laboratory of Liaoning Province, Shenyang, China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology and Vision Science University of Arizona College of Medicine, Tucson, Arizona, United States.
authors.forename: Mingwu
authors.initials: M
authors.lastname: Wang
mesh_terms: D000818:Animals; D051401:Aquaporin 4 / Q000378:metabolism; D051402:Aquaporin 5 / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D003228:Conjunctiva / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D015352:Dry Eye Syndromes / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D007765:Lacrimal Apparatus / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012395:Rose Bengal; D013666:Tears / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D051401:Aquaporin 4; D051402:Aquaporin 5; D015415:Biomarkers; D005456:Fluorescent Dyes; D012395:Rose Bengal