Effect of vitamin A deficiency on the early response to experimental Pseudomonas keratitis. Invest Ophthalmol Vis Sci 1996 Mar;37(4):511-22
Date
03/01/1996Pubmed ID
8595951Scopus ID
2-s2.0-0029871885 (requires institutional sign-in at Scopus site) 24 CitationsAbstract
PURPOSE: Vitamin A-deficient humans and animals are more susceptible to infections than are healthy humans and animals. This study compares the early corneal response (within 24 hours) to an experimental Pseudomonas aeruginosa infection between vitamin A deficient and control rats.
METHODS: Male WAG/Rij/MCW rats were fed either a vitamin A- deficient diet (A-) or the same diet with retinyl palmitate added back in a nonrestricted manner (N) or under pair-fed conditions (A+) to yield weight-matched rats. Some A-rats were repleted wih retinyl palmitate 16 days before being killed and then given free access to the retinyl palmitate-supplemented diet (R). Twenty-four hours before being killed, the corneas of anesthetized rats were scratched and P. aeruginosa organisms were applied to the corneal surface. The rats were killed using an overdose of sodium pentobarbital. Corneas were either processed for light and electron microscopic examination or extracted for proteinase and myeloperoxidase determination. Corneal myeloperoxidase concentrations relative to neutrophil myeloperoxidase concentrations were used to determine the number of neutrophils in the cornea. Zymography was used to study caseinases, gelatinases, and plasminogen activators. Reverse zymography was used to detect proteinase inhibitors. Similar results were noted at early, mid, and late weight plateau stages of vitamin A deficiency.
RESULTS: Ulceration occurred within 24 hours when low numbers of P. aeruginosa (10(4) cpu) were applied topically onto scratched A- corneas, whereas no ulceration was observed in the A+, R, and N corneas. When higher numbers of P. aeruginosa (10(7)-10(8)) were applied to the scratched corneas, all corneas became ulcerated within 24 hours. The extent of ulceration in the control corneas was greater than that in A- corneas by a factor of two. Only the A- corneas contained inflammatory cells with unusual striated deposits in phagolysosomes. The total number of neutrophils in the cornea and the concentrations of caseinases, plasminogen activators, and gelatinases in the infected corneal extracts were similar; however, the concentrations of cysteine proteinase inhibitors were elevated under A- conditions.
CONCLUSIONS: Vitamin A deficiency alters the response of the cornea to a P. aeruginosa infection during the first 24 hours. The alterations observed are probably due to multiple factors: an insufficient tear film for bacterial clearance and migration of neutrophils, epithelial keratinization, alterations in corneal wound healing, and changes in polymorphonuclear function.
Author List
Twining SS, Zhou X, Schulte DP, Wilson PM, Fish B, Moulder JAuthor
Sally S. Twining PhD Assistant Dean, Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsAnticarcinogenic Agents
Blotting, Western
Cornea
Corneal Ulcer
Disease Models, Animal
Disease Susceptibility
Diterpenes
Electrophoresis, Polyacrylamide Gel
Endopeptidases
Eye Infections, Bacterial
Female
Liver
Male
Neutrophils
Peroxidase
Pseudomonas Infections
Rats
Vitamin A
Vitamin A Deficiency
