A dietary factor essential for guinea pigs; the isolation of the antistiffness factor from cane juice.

The existence of a fat-soluble dietary factor essential for guinea pig nutrition was well established through investigations by Wulzen and Bahrs (l-3) and has been confirmed by Anderson and Caldwell.’ The isolation of a highly active fraction from raw cream, capable of alleviating an induced stiffness in guinea pigs, was described by van Wagtendonk and Wulzen (4). It seems apparent from physiological studies that the factor has a regulatory effect on the phosphorus metabolism. One of the most prominent changes found was a sharp decrease in the easily hydrolyzable phosphorus fraction in the liver and kidneys during the deficiency. This fraction responded immediately to the administration of the antistiffness factor to deficient animals in that the values returned to normal after a short time of treatment (5). Similar changes were observed in the concentration of the acid-soluble phosphorus in the muscle. The concentrations of creatine phosphate and adenosine triand diphosphate are lower in the deficient animal (6). As a result of the deranged phosphorus metabolism other, probably secondary, changes are (1) an increase in the concentration of inorganic phosphorus and calcium in the blood, (2) an increase in calcium in the body tissues (7), and (3) an abnormal distribution of the protein nitrogen in the blood (8). Only 3 mg. of an oil, curative in a 0.1 y dosage, were obtained from 55 gallons of raw cream (4). Since much larger amounts of raw cream would have been needed for a successful isolation of the antistiffness factor, it was decided to test other possible sources of raw material for the presence of this factor. It was found that crude cane molasses and crude unheated cane juice were good sources of the factor, the latter being around 100 times as active. Due to the unavailability of crude cane juice, cane molasses was first used for the extraction of the factor. Later cane juice became available and was used exclusively.