VIII. EFFECTS OF DEFICIENCY IN ANIMALS 273 



when the vitamin is not suppHed, the cells are unable to produce intercellu- 

 lar substances such as collagen, ossein, and dentine. The supporting tissues 

 are particularly affected, especially those in which the intercellular sub- 

 stance is calcified. Cell divisions may proceed at almost a normal rate, at 

 least in the early stages of the deficiency, but the cells fail to mature and 

 differentiate and because of this they are unable to perform their special 

 functions. Glazunow^' considers this failure in differentiation to be the pri- 

 mary defect in scurvy. Associated with this condition of immaturity is a 

 disorderly arrangement of the cells, a lack of proper orientation. Possibly 

 the cause of these failures lies primarily in a disorderly arrangement of 

 molecules in the cytoplasm, particularly at the surface of the cell. 



a. Connective Tissue 



Connective tissue is made up of fibers secreted by the fibroblasts^^ • '^ and 

 embedded in an amorphous matrix which may or may not be secreted by 

 cells other than the fibroblasts.^'' ■ ^^ Collagen is the chief but not the only 

 constituent of the fibers. It and its allied substances serve as framework 

 materials for animals much like cellulose, and its allied substances make up 

 the structural elements of plant tissues. Both types of framework substances 

 are characterized by sensitivity to alkali with the production of acidic 

 groups and fission of the chains of longitudinally oriented molecules, poly- 

 peptides in animal fibers and glucose groups in plant fibers. There is evi- 

 dence from x-ray studies, though not conclusive, that in both types of 

 fibers the regularly arranged units are held together by side-chain link- 

 g^ggg 36, 37 Also, in each type of fiber the regularly arranged units are 

 surrounded by non-crystalline interfibrillar material of which carbohy- 

 drates and uronic acids are characteristic constituents. By secondary link- 

 ages with the basic fiber constituents, these carbohydrate-uronic acid 

 groups could presumably serve as gelling agents in both types of tissue. It 

 has been shown''* that the cell walls of embryos in guinea pigs main- 

 tained on an ascorbic acid-deficient diet tend to be indistinct and blurred 

 in appearance in contrast to well-defined cell walls in corresponding tissues 

 of the control animals. A feature suggesting a chemical relationship in the 

 cell framework stmctures of both plants and animals is that crude pecti- 

 nase solutions will dissolve the cementing material in both groups. If this 



31 M. Glazunow, Virchow's Arch, pathol. Anat. u. Physiol. 299, 120 (1937). 



« M. L. Stearns, Am. J. Anat. 66, 133; 67, 55 (1940). 



3' K. R. Porter, Trans. 2nd Conf. on Connective Tissues, New York (1951). 



" M. Staemmler, Frankfurt. Z. Pathol. 25, 391 (1921). 



« B. Sylvan, Acta Chir. Scand. 86, Suppl. 66 (1941). 



" F. O. Schmitt, Physiol. Revs. 19, 270 (1939). 



" W. X. Haworth, Chemistry & Industry 58, 917 (1939). 



'8 M. T. Harnian and L. E. Warren, Trans. Kansas Acad. Sci. 54, 42 (1951). 



