The Fat-soluble vitamins

Bioavilability and Analysis of Vitamins in Foods , Bioavilability and Analysis of Vitamins in Foods , کتابخانه دیجیتال جندی شاپور اهواز

Bioavailability and analysis of vitamins in foods

A simple cubed diet is described, completely adequate to sustain rapid growth and intensive reproduction in mice and rats.

Feeding and breeding of laboratory animals. IX. A complete cubed diet for mice and rats

Summary

1. The available methods for histochemical analysis of lipoids having been reviewed, the following are regarded as valid for the substances or groups indicated: Sudan black: all liquid or grease-like lipoids.



Nile blue sulphate: ‘acidic’ lipoids (lipines, chromolipoids and free fatty acids) as against ‘neutral’ ones (hydrocarbons, triglycerides, higher alcohols, waxes, steroids, carotenoids, etc.).



Fluorescence (without the addition of sulphuric acid): a rapidly fading green is due to vitamin A.



Presence of spherocrystals: lipines, cholesteryl esters (and perhaps other sterol esters as well).



Osmium tetroxide, primary blackening only: for active unsaturated bonds, most usually ethylenic linkages in fatty acid radicles and probably in carotenoids, but also for aldehyde groups (in plasmal), and for various other strong reducers which are not lipoid.



Acid haematein test: phospholipines (possibly acetalphosphatides as well).



Feulgen's plasmal test (not the Feulgen-Verne test): acetalphosphatides by means of the aldehydes liberated from them.



Schultz's method I (modification of Liebermann's reaction): cholesteryl group. Schultz's method II (modification of Lifschiitz's reaction): without a previous oxidation, for certain ill-defined oxidation products of sterols, with a previous oxidation (by light and air, or by ferric compounds) for the cholesteryl group.



Antimony trichloride, and glycerol dichlorhydrin: a transient blue or blue-green is specific for carotenoids.



2. Some of the above tests are subject to interference by certain rare substances; the plasmal test and Schultz's method I may possibly give positive results with certain toad poisons.



3. The following tests are rejected as definitely invalid, insufficiently investigated, or superseded by more satisfactory techniques:



Fischler's technique for fatty acids;



Casanova's reaction;



Ciaccio's methods I and II for ‘lipoids’



The Smith-Dietrich method for phospholipines;



Romieu's method for lecithin;



The Feulgen-Verne technique for plasmal;



Bennett's method for ketosteroids.

The histochemistry of lipoids in animals.

The sections in this article are:


1
Embryonic and Postembryonic Histogenesis of Adipose Tissue
1.1
Occurrence and Appearance of the Primitive Organs of the White Adipose Tissue

1.2
Storage of Fat in the Primitive Organs

1.3
Histogenesis of the Primitive Organs and Their Reticuloendothelial Nature

1.4
Blood Cell Formation in Primitive Organs

1.5
Persistence of the Fat Organ After Loss of the Fat

1.6
Development of the Brown Adipose Tissue




2
Growth and Spreading of Adipose Tissue

The development of adipose tissue

Publisher Summary This chapter focuses on physiological action of vitamin E and its homologues. Studies have shown that the ability of plants to prevent the symptoms of vitamin E deficiency in animals is due solely to the presence of three higher alcohols for which the common designation of tocopherol has been given. None of the other organic compounds known to possess vitamin E action is found in the plant world. The methods used for their isolation from natural sources involved extraction with fat solvents, saponification, partition of the nonsaponifiable fraction between solvents, removal of sterols with digitonin, chromatographic analysis, vacuum distillation, and isolation as crystalline allophanates or as other esters. Molecular distillation from vegetable oils is used extensively for the commercial production of the natural tocopherols; the synthetic forms are readily prepared in the commercial laboratory. In this chapter, nature of vitamin E is elaborated. Chemistry of the tocopherols is discussed. Structural and functional disturbances due to lack of vitamin E is described in detail. Interrelationships of vitamin E with other vitamins are discussed as well.

Karl E. Mason

Papers

Physiological Action of Vitamin E and Its Homologues