Ocular surface in Zn-deficient rats

Area of Science:

• Ophthalmology
• Nutritional Science
• Trace Element Research

Background:

• The ocular surface epithelium, including the cornea and conjunctiva, relies on adequate nutrition for proper structure and function.
• Trace elements, particularly zinc (Zn), play crucial roles in various cellular processes, including enzyme activity and protein synthesis.

Purpose of the Study:

• To investigate the effects of zinc deficiency on the cornea and conjunctiva in rats.
• To elucidate the role of trace elements in ocular surface tissues using advanced imaging and mass spectrometry techniques.

Main Methods:

• Utilized electron microscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS) for detailed analysis.
• Compared Zn-deficient rats with control groups receiving adequate Zn supplementation and a recovery group.

Main Results:

• Observed significant reductions in microvilli and microplicae, and an increase in dark cells in the epithelium of Zn-deficient rats.
• Noted a decrease in goblet cells in the conjunctiva and altered levels of various ions (Zn, Ca, Al, K, Fe, Cl, S) and vitamin C in ocular tissues.
• Corneal epithelium showed increased chloride but decreased calcium and vitamin C.

Conclusions:

• Zinc deficiency negatively impacts ocular surface morphology, affecting epithelial structures like microvilli and goblet cells.
• Disturbed Zn-dependent enzyme activity may impair protein and collagen synthesis, crucial for epithelial integrity.
• Ocular surface changes are associated with altered concentrations of essential trace elements and vitamin C.