Abstract
This study has been carried out to investigate proteinase activity of digestive juice and sucrase activity of midgust tissue in the 5th day of the 5th instar influenced by the dietary composition (quantitative ratio between carbohydrate and protein) and tile rearing temperature during the 4th moulting period. The larvae grew on three kinds of semi-synthetic diet. The A-diet has more carbohydrate than the others, the B-diet has carbohydrate in 1 : 2 with protein, and the C-diet has more protein than the others. All the diets were kept at 16$^{\circ}C$, 25$^{\circ}C$ and 33$^{\circ}C$ during the 4th moulting period. Proteinase activity of digestive juice at the 5th day of the 5th instar was analyzed by Anson's hemoglobin method. Sucrase activity of midgut tissue at the 5th day of 5th instar was analyzed by Somogyi-Nelson's method. The results were as follows. 1. The dietary composition influencing contents of blood sugar was not related to the rearing temperature during the 4th moulting period. The contents of blood sugar appeared to increase in A-diet, B-diet and C-diet order, while proteinase and sucrase activity were stronger in C-diet, B-diet and A-diet order. 2. All kinds of diets showed almost the same fact that proteinase activity at 16$^{\circ}C$ was stronger than that at 32$^{\circ}C$. 3. It was found that sucrase activity became gradualy stronger at 32$^{\circ}C$, 25$^{\circ}C$ and 16$^{\circ}C$ in order in all kinds of diets. 4. There was an interaction in proteinase activity between the dietary composition and the rearing temperature in male larval digestive juice during the 4th mouiting period. On the other hand, there was an inter-acion in sucrase activity between the dietary composition and the rearing temperature in both female and male larval midgut tissue during the 4th moulting period.
누에의 소화액 proteinase 및 중장조직 Sucrase의 활성에 미치는 영양 및 환경의 영향을 알기 위하여, 사료조성중에 당의 함량이 많은 A사료(따라서 단백질의 함량은 적음), 당과백질과의 량비가 약 1 : 2로 적당하다고 생각되는 B사료, 단백질의 함량이 많은 C사료(따라서 당의 함량이 적음)의 3종의 준합성사료를 사용하여 유충을 사육하고, 4면기를 16$^{\circ}C$, $25^{\circ}C$, 32$^{\circ}C$로 각각 보호한 5령 5일째 유충의 소화액 proteinase 및 중장조직 Sucrase의 활성을 조사하였던바 다음과 같은 결과를 얻었다. 1. 유충의 혈당량은 4 면기보호온도와 상관하지 않고 A사료＞ B사료＞ C사료의 순으로 많었으나 소화액 proteinase 및 중장조직 Sucrase의 활성은 C사료＞ B사료 ＞A사료의 순으로 강하였다. 2. 유충의 소화액 proteinase 활성은 A,B,C의 각 사료에 있어서 대개 같은 경향으로, 32$^{\circ}C$ 보다 16$^{\circ}C$에 있어서 강하였으나 혈당량의 변화와는 상반되는 경향이 없다. 3. 유충의 소화액 Sucrase 활성은 A,B,C의 각 사료에 있어서 같은 경향으로, 32$^{\circ}C$＞ $25^{\circ}C$ ＞16$^{\circ}C$의 순으로 강하였으며 또한 혈당량의 변화와 같은 경향이었다. 4. 유충의 소화액 proteinase 활성은 사료조성과 4 면기보호온도와의 교호작용이 웅에서만 인정되었으나 중장조직 Sucrase 활성은 교호작용이 자웅 다같이 인정되었다.