Related Experiment Video
Updated: Jun 19, 2026
05:03
Quantitative Analysis of Dietary Vitamin A Metabolites in Murine Ocular and Non-Ocular Tissues Using High-Performance Liquid Chromatography
Published on: December 27, 2024
VITAMIN A IN EYE TISSUES
1Kaiser Wilhelm-Institut für Zellphysiologie, Berlin-Dahlem, Germany, and the Chemical Institute of the University of Zürich, Zürich, Switzerland.
The Journal of General Physiology
|October 30, 2009
Summary
Vitamin A was identified in the retinas and pigment layers of various animals, including mammals and frogs. Its presence was confirmed through absorption spectroscopy, chemical tests, and biological activity assays.
Area of Science:
- Biochemistry
- Ophthalmology
- Comparative Anatomy
Background:
- Vitamin A is crucial for vision and growth.
- Previous research indicated Vitamin A's presence in ocular tissues.
Purpose of the Study:
- To identify and quantify Vitamin A in the ocular tissues of different animal species.
- To confirm the presence of Vitamin A using multiple analytical methods.
Main Methods:
- Spectrophotometry to determine specific absorption at 328 nm.
- Chemical tests, including the antimony trichloride reaction (blue color at 620 nm).
- Assays for anti-xerophthalmic and growth-promoting biological activities.
Main Results:
- Vitamin A was detected in the retinas and pigment epithelia/choroid of frogs, pigs, sheep, and cattle.
- Quantification revealed significant concentrations: ~400 µg/g in frog retinas, ~2 mg/g in frog pigmented layers, and ~22 µg/g in mammalian retinas.
- No other carotenoids, except possibly hepaxanthin, were found in mammalian tissues.
Conclusions:
- Vitamin A is a significant component of ocular tissues in both amphibians and mammals.
- The study provides quantitative data on Vitamin A distribution in these tissues.
- Multiple lines of evidence confirm the identification and presence of Vitamin A.
Related Concept Videos
01:17Accessory Structures of the Eye
Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
01:22Connective Tissue Cell Types
Connective tissue develops from the mesoderm of a developing embryo and consists of cells, fibers, and ground substance: a gel-like material containing large complexes of carbohydrates and proteins. Connective tissue was first identified as a separate tissue family in the 18th century, and Johannes Peter Muller coined the term connective tissue.
Fat cells (adipocytes), smooth muscle cells (myoblasts), and bone cells (osteoblasts) are some connective tissue cell types. Some immune system cells...
Fat cells (adipocytes), smooth muscle cells (myoblasts), and bone cells (osteoblasts) are some connective tissue cell types. Some immune system cells...
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
01:23Role of Skin in Vitamin D Synthesis
The skin plays a crucial role in the synthesis of vitamin D, a vital nutrient for various physiological processes in the body. Vitamin D is unique because it can be synthesized in the skin through a series of chemical reactions triggered by exposure to ultraviolet B (UVB) radiation from sunlight.
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
01:31Lipid-derived Compounds in the Human Body
Fats and lipids are crucial components in the human body. Some lipid-derived compounds, such as fat-soluble vitamins, eicosanoids, lipoproteins, and glycolipids, also play unique roles to support various biological processes .
Fat-soluble Vitamins
Fat-soluble vitamins, including vitamins A, D, E, and K, are required in minimal quantities, but their deficiencies can lead to severely abnormal physiological conditions. For example, vitamin A deficiency can cause night blindness, dry skin, delayed...
Fat-soluble Vitamins
Fat-soluble vitamins, including vitamins A, D, E, and K, are required in minimal quantities, but their deficiencies can lead to severely abnormal physiological conditions. For example, vitamin A deficiency can cause night blindness, dry skin, delayed...