Effect of increased oxygen of hydroxyproline synthesis in the cuticle and body wall of Ascaris lumbricoides

Abstract

1. 1. Ascaris lumbricoides injected with [ 14C]proline were incubated for 24 h in 70% O 2 at normal pressure and in air at 1.6 atm abs. 2. 2. In Ascaris incubated at high O 2 concentration a substantial increase in collagenous proline hydroxylation occured (1.6–3 times) in the cuticle while little effect of perhaps a decrease in hydroxyproline synthesis was observed in the body wall. 3. 3. When incubating Ascaris at four varying concentrations of O 2 (0, 5, 20 and 70%) the hydroxylation of proline (given as ration specific activity hydroxyproline/specific activity proline) measured in purified cuticle collagen was maximal when the worms were under 70% O 2 and 4 times higher than when under N 2. In the case of muscle collagen, hydroxylation was maximal at 20% O 2; 70% O 2 was no better than N 2. 4. 4. The results are discussed in terms of two different protocollagen proline hydroxylases; one in the cuticle stimulated by O 2 and one in the body wall that is perhaps slightly inhibited by high O 2. Alternatively, the results may be due to differences mainly in the availability of O 2 to protocollagen hydroxylase in the two body layers. 5. 5. Data are presented on the distribution of various forms of collagenous hydroxyproline in Ascaris cuticle and body wall.