Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course ...Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course of fertilization (0-4 h after egg laying), thelevel of H_2O_2 content reached its peak value at 2.5 h of the developmental course and the activity ofsuperoxidase dismutase (SOD) was at higher level while the activity of catalase (CAT) at the lowestcorrespondingly; 2) The H_2O_2 content in embryo, in which the diapause of eggs was being relievedthrough treatment with hydrochloric acid on time in the course of embryonic development, wassignificantly higher than that of diapause eggs except the lower level showed in the embryo whenthe development of it went on for 168~216 h and the activity of SOD reached, lower and higher,tWo peaks in 72 and 168 h after egg-laying, respectively, and was significantly higher in late stagewhile the activity of CAT was shown with a stable level in the period of 72-192 h after egg-laying,and, after then, a rapid rising occurred in the embryo. The level of the CAT activity in embryowas shown significantly lower than that in diapause eggs in early period and higher in late stage ofegg development; 3) In the course of formation of diapause in eggs, the level of H_2O_2contentchanged smoothly and the activity of SOD changed vigorously in early period, and kept stable statelater; and the CAT activity increased gradually; while in the course of relief of diapause under ontime-treatment with hydrochloric acid, the level of H_2O_2 was significantly higher than that indiapause eggs and the SOD activity displayed a new peak value and significantly rose in later stage,while the activity of CAT in relieving embryo from diapause was signincantly lower than that indiapause eggs. Combining the results obtained in other researches with those from ours mentionedabove, we suggest that the metabolism of H_2O_2 might be of importance in the courses of formationand relief of diapause in silkworm eggs. Maybe the esterase A4 timer hypothesis and themicropylar barrier to oxygen hypothesis could be integrated for explanation of the course offormation and relief of diapause in silkworm eggs.展开更多
文摘Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course of fertilization (0-4 h after egg laying), thelevel of H_2O_2 content reached its peak value at 2.5 h of the developmental course and the activity ofsuperoxidase dismutase (SOD) was at higher level while the activity of catalase (CAT) at the lowestcorrespondingly; 2) The H_2O_2 content in embryo, in which the diapause of eggs was being relievedthrough treatment with hydrochloric acid on time in the course of embryonic development, wassignificantly higher than that of diapause eggs except the lower level showed in the embryo whenthe development of it went on for 168~216 h and the activity of SOD reached, lower and higher,tWo peaks in 72 and 168 h after egg-laying, respectively, and was significantly higher in late stagewhile the activity of CAT was shown with a stable level in the period of 72-192 h after egg-laying,and, after then, a rapid rising occurred in the embryo. The level of the CAT activity in embryowas shown significantly lower than that in diapause eggs in early period and higher in late stage ofegg development; 3) In the course of formation of diapause in eggs, the level of H_2O_2contentchanged smoothly and the activity of SOD changed vigorously in early period, and kept stable statelater; and the CAT activity increased gradually; while in the course of relief of diapause under ontime-treatment with hydrochloric acid, the level of H_2O_2 was significantly higher than that indiapause eggs and the SOD activity displayed a new peak value and significantly rose in later stage,while the activity of CAT in relieving embryo from diapause was signincantly lower than that indiapause eggs. Combining the results obtained in other researches with those from ours mentionedabove, we suggest that the metabolism of H_2O_2 might be of importance in the courses of formationand relief of diapause in silkworm eggs. Maybe the esterase A4 timer hypothesis and themicropylar barrier to oxygen hypothesis could be integrated for explanation of the course offormation and relief of diapause in silkworm eggs.
