A marked inhibition of the incorporation of S35-sulfate by normal calf costal cartilage was produced by potassium ascorbate in the presence of catalytic amounts of cupric ions. The effect of the various components of the ascorbic acid oxidizing system (potassium ascorbate, cupric ions, cuprous ions, hydrogen peroxide, dehydroascorbie acid) was investigated. The results of experiments in which hydrogen peroxide, catalase, or sodium azide were used singly or in combination suggest that the inhibition produced by the aseorbic acid oxidizing system is due, to a considerable extent, to the production of hydrogen peroxide. Dehydroaseorbie acid was also found to inhibit the incorporation of S35-sul/ate by cartilage slices. However, the gradual fall in pH which resulted from the addition of dehydroaseorbic acid could account to a large extent for the inhibitory effect observed because the incorporation of S35-sulfate by cartilage slices decreases sharply as the pH is lowered. The incorporation of SSS-sulfate by cartilage slices is inhibited also by increasing the concentration of phosphate.The state of ascorbic acid deficiency is associated with a defect in the production of intracellular ground substance. The component of ground substance primarily affected, and the mechanisms involved, have not, as yet, been clearly elucidated. A decrease in the incorporation, of S35-sulfate into granulation tissue (1-3), cartilage (4), and a number of other tissues (5) has been observed in scorbutic guinea pigs. Earlier work (6, 7) has established that most of the S36-sulfate retained by an animal beyond 24 hours is found in sulfated mucopolysaccharides. Bostr6m and M~.nsson (8) have studied the incorporation of S36-sulfate into the chondroitin sulfate of costal cartilage slices prepared from normal calves and have indicated a number of factors which influence this reaction. The influence of ascorbic acid on the incorporation of SSS-sulfate by slices of costal cartilage from normal calves is considered in the present communication.* Arthritis and Rheumatism Foundation Fellow.
The maximal accumulation of S 8~ in the epiphyseal cartilage of suckling rats occurs about 24 hours after the intraperitoneal injection of S~-sulfate (1), at which time the isotope is most highly concentrated in the epiphyseal cartilage plate (2). Thereafter, the concentration of S s6 in the epiphyses decreases rather slowly, the decrease being most noticeable in the epiphyseal cartilage plate and in regions of the epiphyses where ossification centers develop. In the diaphyses, on the other hand, there is a rapid rise and fall in the concentration of the isotope so that by the 4th hour only a faint autoradiographic reaction is elicited. Beginning at about the 24th hour the concentration of S 86 is seen to increase in the metaphyses. Because of the concurrent decrease of the concentration in the epiphyseal cartilage plate and increase in the metaphyses, it seemed likely that the S 8~ is transferred from the cartilage plates to the metaphyses, where it accumulates as inorganic sulfate or/and as some other compounds, of which the precursor is the chondroitin sulfate of the cartilage (2). Indeed, it has been reported that after the administration of S86-sulfate to dogs (3, 4), rabbits (5), and rats (6) the isotope in the bones can be separated into two forms, one of which probably is inorganic sulfate and the other a material akin to chondroitin sulfate.Experiments were undertaken to ascertain the nature, and the changes in concentration, of the S86-1abelled materials in epiphyses and diaphyses of suckling rats after administration of S3~-sulfate. The hope was that the findings would partially indicate the mechanisms involved in the development of the metaphyses. The results are presented here.EXPEI~ rM~.NTAL Experiment L--One hundred #c. of S 8~ as sodium sulfate I was injected intraperitoneally into each of twelve 7 day old rats, which were then returned to their mothers. Two animals
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.