급성 및 만성 영양장애가 소화효소 활성 및 세포기능에 미치는 실험적 연구

김윤수,황석귀,김명원,유용운,송정석 ( Yoon Soo Kim,Suk Kuy Whang,Myung Won Kim,Yong Wun Ryu,Chung Suk Song ) 생화학분자생물학회 1974 BMB Reports Vol.7 No.1

A variety of digestive Enzymes of pancreatic and intestinal origin participate in the breakdown of protein, carbohydrate and lipids. It has been known that some of enzyme output of the intestinal glands can be manipulated by altering components of the diet. The incidence of patients who are suffering from gastrointestinal trouble in Korea is much higher than that of the United States. This fact might correlate with diet composition of Korean and American dishes. These facts are attractive for us to study the effect of diet composition on the digestive enzymes such as amylase, lipase, trypsin and chymotrypsin, and to decide whether the difference of diet composition affects these enzymes and whether such high incidence of gastroin testinal patients in Korea could be adequately explained by change in digestive enzyme activities of the animals fed with different diet. Our previous experiments have shown that pancreatic enzyme activites of rats fed with 5% casein diet which was prepared similarly to Korean diet in terms of protein content only were depressed as much as one fifth of that of control during two weeks feeding period. but it is true that protein is not only depleted but fat is also depleted in Korean dishes. The primary objective of the experiments described herein was to study the effect on the pancreatic enzyme activities of diet which was similarly prepared to Korean dishes and also to study the effect on the pancreatic enzyme activities of varying the proportion of fat to carbohydrate in the diet which is keeping the diet isonitrogenous and isocaloric. Data from this experiment will be discussed ire conjunction with previously published results conducted in our laboratory in order to illustrate how the high incidence of gastrointestinal patients in Korea could be adequately explained by diet prepared in similar composition to the Korean dishes. In a random distribution, male albino rats, weighing the average of 80 gm each were divided into five groups. Group I ; 5% casein : no fat : carbohydrate Group II ; 5% casein : 12% fat : carbohydrate Group III ; 18% casein : no fat : carbohydrate Group IV ; 18% casein : 12% fat : carbohydrate Group V ; 18% casein : high fat : carbohydrate (ratio of fat to carbohydrate 94 : 6) Calorie difference from protein or fat depletion was substitiuted by carbohydrate. At the end of designated time interval, the rats were sacrificed 14-15 hours after the last meal by decapitation. The pancreas was carefully romoved and placed in a cold 0. 25M sucrose solution (4℃). A 5% homogenate in 0.25M sucrose was prepared from the glandular {free of obvious lymph nodes and adipose tissue) portion of the pancreas. 5:% Homogenates were centrifuged (14,000 x g) for 15 minutes to remove cellular debris and whole cells. Enzyme analysis and protein determination were subsequently performed on the supernatant. Protein was determined by Lawry method (1951). Enzyme activity assays were performed using modification of Hepler method (1962) for amylase and the method developed by Cherry and Crandall (1932) for lipase. Chymotryptic assays were performed using a modification of method developed by Rhodes et al. (1957), as a substrate for chymotrypsinogen N-acetyl-L-tyrosine ethyl ester was used. Trypsinogen assay was similarly performed using p-toluene-sulfonyl-L-arginine methyl ester as a substrate. The assays were linear with respect to enzyme concentration over the range used under specified conditions such as temperature (37℃) and incubation period, 30 minutes for amylase, 1 hour for lipase, and for the trypsinogen and chymotrypsinogen the recording of dye disappearing of optical density was recorded 2 to 3 seconds after adding substrate-buffer-indicator The results of the experiments in which the effect of different composition of nutrient which was prepared in similar composition to Korean dishes on pancreatic enzyme acitivities are summarized as the following. When the enzyme activity

기질이 이당류 분해효소 적응성에 미치는 실험적 연구

김윤수,황석귀,송정석 ( Yoon Soo Kim,Suk Kuy Whang,Chung Suk Song ) 생화학분자생물학회 1975 BMB Reports Vol.8 No.2

In most mammals, levels of lactase are high during infancy but by the time adulthood is reached these levels of lactase are deficient. So far, the exact mechanism involved in the appearance and disappearance of lactase is not known. The present experimental study describes the digestive enzymatic adaptation of disaccharidase to the substrate in diet composition in order to investigate whether the mere presence of corresponding substrate in the diet suffices to stimulate disaccharidase or not, probably by $quot;turning on$quot; which encodes for the synthesis of these enzymes. Our experimental studies suggest that lactase activity in the newborn of the rat immediately after normal birth is at a peak and remains there through the lactating period; however, disappearance of lactase was observed four days after weaning. It reappeared in seven days after the rat, which had been fed for 150 days on a sucrose diet, was shifted to a lactose diet, However, the activity was weaker than that of the lactating period, indicating that enzymatic adaptation of latose to the substrate in diet may be related. On the other hand no surcease levels were found throughout the lactating period, but the levlel of surcease rose independently of the sucrose diet intake after weaning, indicating that the sucrose in the diet did not seem to influence the surcease activity at all.

급성 및 만성 영양장애가 소화효소 활성 및 세포기능에 미치는 실험적 연구

김윤수,황석귀,김명원,유용운,송정석,Kim, Yoon-Soo,Whang, Suk-Kuy,Kim, Myung-Won,Ryu, Yong-Wun,Song, Chung-Suk 생화학분자생물학회 1974 한국생화학회지 Vol.7 No.1

저자들은 한국인 주식에 흡사한 각종 식이 조성을 달리한 인공 식이가 취장소화효소 활성에 어떻게 영향을 미치며 이들 식이 조성차이와 소화효소 활성과의 함수관계를 알아 보기 위하여 식이 조성을 달리한 각종 식이를 가지고 실험한바 다음과 같은 실험결과를 얻었다. 식이 I군(저단백, 무지방, 고함수탄소)과 식이 II군(저단백, 정상지방, 고함수탄소)으로, 4주 또는 6주동안 사육후 백쥐의 취장 소화 효소 활성을 측정하여 그 변화를 비교 관찰하였다. 정상식이(정상단백, 정상지방, 정상 함수탄소)로 해당 기간 동안 기른 쥐의 각 효소 활성치를 100%로 표시할 때 식이 I, 식이 II로 2주 동안 기른 쥐 취장 소화 효소 chymotrypsinogen은 정상치의 0~10% trypsinogen은 0~20% amylase는 10~15%, lipase 20~25%로 저하 하였다. 이와 같은 효소 활성치의 저하는 계속 4주 6주에도 유지 하였으며 식이 III군(정상단백, 무지방, 고함수탄소)에서는 정상군과 하등의 변화가 없이 소화효소 활성치를 유지하였다. 즉 소화효소 chymotrypsinogen, trypsinogen, amylase, lipase 이들 모든 효소 활성은 우리가 사용한 지방의 함량에 하등의 영향을 받지 아니 하였으며 식이중 단백질 함양유무(18%)가 효소활성 저하의 중요한 요인의 하나라는 사실을 실험적으로 입증하였다. 이와 같이 식이 조성 차이로서 저하된 각식이군의 효소 활성도는 4주, 6주에 정상식이로 대체 하였을 때 식이 I, II로 4주, 6주동안 사육한 기간에 상관없이 식이 대체 3일만에 chymotrypsinogen, trypsinogen, Iipase는 정상치로 회복하였으며 amylase는 4주에 대체한 것이 5일, 6주에 대체한 것이 7일을 요하였다. 즉 식이에 의한 amylase 효소 활성 회복 반응은 chymotrypsinogen, trypsinogen, lipase와 상이 하였다. 4, 6주후에 정상식이 대신 저단백(5%) 고지방(78%) 저함수탄소(17%)로 조성된 고 지방식이로 대체 하였을때 소화효소는 전혀 회복을 보이지 아니한 사실로 미루어 보아 소화효소 활성 회복에는 단백질함양이 절대필수요소 임을 실험적으로 입증하였으며 지방은 전혀 관계하지 않은 사실도 압증하였다. 정상단백질(18%)이 일정하고 고지방(78%) 저함수탄소(5%) 식이로 3주, 4주 동안 기른 쥐의 취장내 효소활성 chymotrypsinogen, trypsinogen, lipase는 하등의 영향을 받지 아니 하였으며 amylase 치만이 정상치 100% 보다 3주에 61.5%, 4주에 64%로 저하된 효소 활성치를 보였다. Amylase는 지방 함양보다 함수탄소양에 영향 받은 것 같다. 이상과 같은 우리의 실험적 사실은 취장 소화 효소 활성은 식이조성 차이로서 영향 받으나 지방 함양의 다소 유무에 하등의 영향을 받지 아니하고 오로지 단백질 함양 만이 그들효소의 활성 및 회복에 필수요소 임을 실험적으로 입중하였으며 amylase는 단백질 함양에도 영향 받으나 단백질 함양이 정상이고 함수탄소양을 줄인 고지방식이(함수탄소 : 지방 6 : 94)는 amylase 활성에 영향을 미친다는 사실도 구명하였다. the corresponding tissue fed with normal diet, the enzyme activities of chymotrypsinogen, trypsinogen, amylase and lipase were depressed by 0-10%, 0-20%, 10-15% and 20-25% respectively at the end of two weeks during the feeding of group I and group II and then these range of depletion of enzyme activities maintained continuously up to the end of tour and six weeks. This result suggests that digestive enzyme activities are influenced by only depletion of protein but not by various amount of fat in diet at all when carbohydrate is sufficient. Some of animals in groups I and II receiving designated diet for four and six weeks were transferred to the normal diet then pancreatic enzyme were assayed on the third, fifth and seventh days. The recovery of these enzymes is remarkable, and apparently the rats fed protein-and lipid-depleted diet were able to respond immediately to the stimulus of diet. Complete recovery of chymotrypsinogen, trypsinogen and lipase was observed after three days feeding regardless rats fed with protein- and lipid-depleted diet for four or six weeks except amylase which was recovered after five days feeding in the group of rats fed diet I and II for four weeks and seven days feeding in the group of rats fed diet I and II for six weeks. No difference in the recovery rate of enzyme was observed between diets I and II and also between the group of the rats when the rats in groups I and II shifted to the normal diet at four weeks and six weeks. Rats fed protein- and lipid-depleted for four and six weeks were not able to respond to the stimulus of diet, at all, which consists of high lipid. low protein, and low carbohydrate. This result illustrates that the essential factor for stimulus of enzyme activity is protein in diet but not carbohydrate and fat. The effect of high proportion of fat to carbohydrate (94: 6) in isonitrogenous, isocaloric diet on pancreatic enznyme activities also was studied in rats and compared to the effect of normal isocaloric diet. The diet which provided 57 cal/day and the experiment lasted for four weeks, no effect of this diet on pancreatic chymotrypsinogen, trypsinogen and lipase was observed. However, pancreatic amylase was reduced to 61.5% at the end of three weeks and 64% at the end of four weeks. This result indicates that pancreatic amylase activity may be related when carbohydrate is restricted but protein is normal in diet. These results indicate that when various dietary composition is related to the pancreatic enzyme activity, one of main influential factor in diet on pancreatic enzyme is protein, but not fat at all. However pancreatic amylase acivity may be related when carbohydrate is resticted but protein is normal in diet. Our experimental evidence tends to indicate that enzyme synthesis in the pancreas is regulated, at least in part by the composition of amino acid pool(s) in the acinar cells of pancreas. This may be due to the decreased amount of amino acid in the dietary protein, but not composition of fat. It can be postulated that the decrease in the dietary protein affects synthesis and secretion of pancreatic digestive enzymes, and then the intracellular structure of the cell, resulting in decrease of cell activity and tissue debility.

설탕과 전분이 간장내 지방합성 효소활성에 미치는 영향

황석귀,김윤수 ( Suk Kuy Whang,Yoon Soo Kim ) 생화학분자생물학회 1978 BMB Reports Vol.11 No.1

Investigations in our laboratory have been undertaken to study the response of ATP-citrate lyase and glucose-6-phosphate dehydrogenase in the liver of rats which were fed one of the following diets; 47 % carbohydrate, 18 % protein as casein and 35% fat. In various experiments, the carbohydrate used was either 1) 47% starch 2) 47% sucrose 3) 36%ethanol with 11% sucrose. All diets contained adequate amounts of all vitamins and all mineral. The animals were sacrificed by decapitation, and the liver was removed and prepared immediately for assay of enzyme activities. ATP-citrate lyase was assayed by the method of Cottam & Srere (1969), glucose6-phosphate dehydrogenase assayed by method of Bergmeyer (1965), and soluble protein was determined by the method of Lowry et al. (1951). The liver ATP-citrate lyase activity of the rats groups which had been feed the 3 different diets for 4 weeks had a ATP-citrate lyase level in group 2 that was over 5 times higher than that of group 1. The effect of refeeding of group 1 and group 2 diets to the rats which had received the group 3 diet for 4 weeks, changed the level of ATP-citrate lyase level in group 2 diet and increased it 4 times over that of the group 1 level. No activity difference was observed between starch group i and ethanol group 3. Another of our experiments indicated that ATP-citrate lyase and glucose-6phosphate dehydrogenase were induced by sucrose and starch in the: presence of adequate protein, particularly, ATP-citrate lyase induction on sucrose was over 2 times that of starch. The refeeding of these two diets for 3 days following starvation of 3 days results in a remarkable induction were observed in the levels of these two enzymes, the induction of ATP-citrate lyase was greater than that of glucose-6-piaosphate dehydrogenase on the sucrose diet compared to the starch diet when compared with that of actinomycin D treated rat, apparently due to a marked increase in the synthesis of these enzyme protein. It was also demonstrated that adequate amounts of protein in diets are required for induction to occur of these enzymes as for the digestive enzymes such as trypsinogen, chymotrypsinogen and amylase as shown by one of our previous studies.

설탕과 전분이 간장내 지방합성 효소활성에 미치는 영향

황석귀,김윤수,Whang, Suk-Kuy,Kim, Yoon-Soo 생화학분자생물학회 1978 한국생화학회지 Vol.11 No.1

저자들은 백서에 함수탄소를 달리한 식이및 알콜투여가 백서간장내 지방산 합성에 관여하는 효소활성에 어떻게 영향을 미치며 이들 식이 조성차와 효소활성과의 상호 관계를 구명하기 위하여 각종식이를 가지고 실험한바 다음과 같은 실험 결과를 얻었다. 1. 웅성백서를 두군으로 나누어 Decarli 및 Lieber (1967)의 식이조성 방법에 다라 식이내 지방이 19.5%가 포함되게하고, 함수탄소 공급원으로 설탕을 대치하고, 함수탄소에서 오는 일부열량을 알콜로 대치하여 4주간 사육하였다. 설탕식이를 투여한 백서간장내 ATP-citrate lyase 활성은 알콜투여군에 비하여 5배가 높았다. 2. 알콜을 4주간 투여하여 효소활성이 설탕식이군에 비하여 낮은 상태의 백서에 설탕 및 전분식이로 대치하여 2주간 투여한 백서의 간장내 ATP-citrate lyase 활성은 설탕식이를 투여한 백서에서 전분식이 투여군에 비하여 4배가 높았으며 전분식이군의 효소활성은 알콜투여군과 하등의 변화가 없었다. 3. 설탕식이와 전분식이를 정상백서에 각각 1주일간 투여후 간장내 ATP-citrate lyase 활성이 설탕식이 투여군은 전분식이 투여군보다 3.7배 높았고, glucose-6-phosphate dehydrogenase 호라성은 설탕투여군에서 전분식이 투여군에 비하여 5배의 증가가 있었다. 4. 백서를 1주일간 전분식이로 사육후 백서를 네군으로 나누어 1군은 전분식이를 계속 투여하고 2, 3, 4 군은 3일 굶긴다음 2군에는 설탕식이 재투여군, 3군은 전분식이 재투여군, 4군은 설탕식이 재투여 하면서 actinomycin D를 처리군으로 각각 식이를 3일간 재투여 한 다음 효소 활성을 관찰 하였다. ATP-citrate lyase 활성은 설탕식이 재투여군에서, 전분식이를 계속투여군(정상군)에 비하여 12.5배가 증가하고 저눈식이 재투여군은 6.35배가 증가하였다. 또한 설탕식이 재투여군 효소 활성은 전분식이 재투여군에 비하여 2배의 증가가 있었다. Glucose-6-phosphate dehydrogenase 활성은 정상군에 비하여 설탕식이 재투여군에서 6.4배가 증가하였으며, 전분식이 재투여군에서 4.57배의 증가를 보였으나 설탕식이 재투여군의 효소 활성은 전분식이 재투여군에 비하여 1.5배의 증가를 보였다. 설탕식이를 재투여와 동시에 actinomycin D를 처리하면 ATP-citrate lyase 및 glucose-6-phosphate dehydrogenase 활성이 전혀 증가하지 아니 하였다. 이상과 같은 실험 결과로 미루어 보아 알콜에의한 지방간 형성은 간장내 지방산 합성율과 밀접한 관계가 없는듯 하며 설탕식이는 전분식이에 비하여 간장세포질내 지방합성에 밀접하게 관여하는 ATP-citrate lyase 및 glucose-6-phosphate dehydrogenase 활성은 식이내 지방함량에 관계없이 현저하게 증가시키고, 설탕식이에 의한 이들 효소활성증가는 gene level에서 효소합성이 증가하는 것으로 사료된다. Investigations in our laboratory have been undertaken to study the response of ATP-citrate lyase and glucose-6-phosphate dehydrogenase in the liver of rats which were fed one of the following diets; 47% carbohydrate, 18% protein as casein and 35% fat. In various experiments, the carbohydrate used was either 1)47% starch 2) 47% sucrose 3) 36%ethanol with 11% sucrose. All diets contained adequate amounts of all vitamins and all minerals. The animals were sacrificed by decapitation, and the liver was removed and prepared immediately for assay of enzyme activities. ATP-citrate lyase was assayed by the method of Cottam & Srere (969), glucose-6-phosphate dehydrogenase assayed by method of Bergrneyer (1965), and soluble protein was determined by the method of Lowry et al. (1951). The liver ATP-citrate lyase activity of the rats groups which had been feed the 3 different diets for 4 weeks had a ATP-citrate lyase level in group 2 that was over 5 times higher than that of group 1. The effect of refeeding of group 1 and group 2 diets to the rats which had received the group 3 diet for 4 weeks, changed the level of ATP-citrate lyase level in group 2 diet and increased it 4 times over that of the group 1 level. No activity difference was observed between starch group 1 and ethanol group 3. Another of our experiments indicated that ATP-citrate lyase and glucose-6-phosphate dehydrogenase were induced by sucrose and starch in the presence of adequate protein, particularly, ATP-citrate lyase induction on sucrose was over 2 times that of starch. The refeeding of these two diets for 3 days following starvation of 3 days results in a remarkable induction were observed in the levels of these two enzymes, the induction of ATP-citrate lyase was greater than that of glucose-6-phosphate dehydrogenase on the sucrose diet compared to the starch diet when compared with that of actinomycin D treated rat, apparently due to a marked increase in the synthesis of these enzyme protein. It was also demonstrated that adequate amounts of protein in diets are required for induction to occur of these enzymes as for the digestive enzymes such as trypsinogen, chymotrypsinogen and amylase as shown by one of our previous studies.

Flavin Analogue 가 백서 간장내 포도당 및 지방 대사에 미치는 영향

김원용,황석귀,김윤수 ( Won Yong Kim,Suk Kuy Whang,Yoon Soo Kim ) 생화학분자생물학회 1978 BMB Reports Vol.11 No.1

Lambooy (1961) has shown that, while several analogues of riboflavin are able to replace the vitamins in the metabolism of some microorganism, 7-ethyl-8-methyl flavin is able to serve as the sole flavin in the metabolism of the rat. This flavin is able to serve as a completely adequate replacement for riboflavin in the metabolism of Wistar (Lambooy, 1961) and Sprague-Dawley rats (Yoon S. Kim et al, 1966) in terms of growth, survival, optimal physical appearance, and efficient utilization of food. Administration of 7-ethyl-8-methyl flavin to weanling rats as their only source of flavin permits a normal growth with a concomitant rapid and extensive loss of succinic dehydrogenase activity (SDH) from the liver, heart and kidney to within 24, 48, and 67% of the normal level, respectively, on day 42 following initiation of a 7-ethyl-8-methyl flavin diet. This result was essentially identical with that previously reported (Y.S. Kim and Lambooy, 1967). The purpose of the experiments described here is to study whether the decreased SDH activity in the tissue of rats is related to the metabolism of glucose and de novo biosynthesis of lipid from glucose in the liver of rats when D-glucose-^(14)C(U) is administered intraperitoneally to the rat maintaining SDH activity from liver, heart and kidney at 24, 48 and 67% of the normal level. This is also to study whether the total triglyceride and the total lipid content in the liver of rats is influenced by the loss of SDH activity in the liver of rats which have received 7-ethyl8-methyl flavin. The present study shows that there wa.s no significant difference in the total amount of ^(14)CO₂ expired from D-glucose-^(14)C(U) through the respiration of rats which had received 7-ethyl-8-methyl flavin compared to control rats which received riboflavin, indicating that the metabolic rate of glucose in the tissues of rat receiving 7-ethyl-8-methyl flavin is similar to that of the control rats. However, compared to the control level only 50% of ^(14)C total lipids were incorporated by de novo biosynthesis from D-glucose-^(14)C(U) in the liver of rats receiving 7-ethyl-8-methyl flavin but the total content of triglyceride and total lipids in the liver of rats receiving 7-ethyl-8-methyl flavin were increased by 29 and 30% over the normal level. This may be due to the increased of lipid transport from the peripheral adipose tissue due to the decreased SDH activity in the liver of rats.

한국인의 유당 분해효소

정명희,황석귀,김윤수,송정식 ( Myung Hee Chung,Suck Kuy Whang,Yoon Soo Kim,Chung Suk Song ) 생화학분자생물학회 1973 BMB Reports Vol.6 No.3

Twenty six oral lactose tolerance tests were performed in 21 healthy subjects and five patients. Each subjects were given 50gm of lactose in 300m1 of water. Venous blood sugar was measured at 0, 30, 60, 90 and 120 min. All 26 subjects showed a rise in blood sugar less than 25㎎ per 100㎖ (flat curve) above the fasting level. At least one or more of G. I. symptoms such as bloating, abdominal cramps and/or diarrheas were experienced by all subjects during and/or after the tests. Additional glucose and galactose tolerance tests performed in 3 subjects were normal and this excluded the possibility of absorptive defect in these individuals. In order to determine the lactase activity of the Korean adults, peroral mucosal suction biopsies were done in another 10 subjects who were randomly selected. In all the subjects, the activities of lactase were absent whereas those of sucrose were normal. The majority, if not all, of Korean adults are expected to have lactase deficiency.

Lactase Deficiency In Korean Adults

정명희,황석귀,김윤수,송정석,Chung, Myung-Hee,Whang, Suck-Kuy,Kim, Yoon-Soo,Song, Chung-Suk 생화학분자생물학회 1973 한국생화학회지 Vol.6 No.3

유당 분해 효소 lactase의 활성도는 일반적으로 분만과 동시에 최고치에 달하고 이유와 동시에 그 활성도는 서서히 떨어져서 성인에 이르르면 lactase 활성도는 민족에 따라서 다른 것으로 보고되고 있다. 그 원인이 그 민족의 환경 및 식사습성과의 관계 혹은 민족적 유전인자의 차이로 인한 것으로 설명하려 하고 있으나 어느쪽이 옳은 설명인지는 아직 모른다. 주위 환경과 음식 습성 및 민족의 기원이 상이한 한국인에 대한 이런 실험 보고는 아직 없기에 한국 성인을 대상으로 소정의 실험을 시도 하였다. 한국 성인에 유당을 부하하면 100%에서 유당분해효소 lactase가 결핍으로 오는 저혈당치를 보였으며 또한 한국성인에서 경구적으로 multipurpose rubin tube를 사용해서 얻은 생체 부검 조직내의 설탕분해 효소 sucrase는 정상치 인데 비하여 유당 분해 효소 lactase치는 실험대상 전원에서 그 활성도를 찾아 볼수 없었다. 이 원인이 한국인의 환경과 식이 습성에서 유래한 것인지 또는 조상때 부터 민족적인 어떤 유전인자 관계인지는 다른 민족에서 보고 된것 처럼 그 기전은 아직 모른다. Twenty six oral lactose tolerance tests were performed in 21 healthy subjects and five patients. Each subjects were given 50gm of lactose in 300ml of water. Venous blood sugar was measured at 0, 30, 60, 90 and 120 min. All 26 subjects showed a rise in blood sugar less than 25mg per 100ml (fiat curve) above the fasting level. At least one or more of G. I. symptoms such as bloating, abdominal cramps and/or diarrheas were experienced by all subjects during and/or after the tests. Additional glucose and galactose tolerance tests performed in 3 subjects were normal and this excluded the possibility of absorptive defect in these individuals. In order to determine the lactase activity of the Korean adults, peroral mucosal suction biopsies were done in another 10 subjects who were randomly selected. In all the subjects, the activities of lactase were absent whereas those of sucrase were normal. The majority, if not all, of Korean adults are expected to have lactase deficiency.

Flayin Analogue가 백서 간장내 포도당 및 지방 대사에 미치는 영향

김원용,황석귀,김윤수,Kim, Won-Yong,Whang, Suk-Kuy,Kim, Yoon-Soo 생화학분자생물학회 1978 한국생화학회지 Vol.11 No.1

Lambooy (1961) has shown that, while several analogues of riboflavin are able to replace the vitamins in the metabolism of some microorganism, 7-ethyl-8-methyl flavin is able to serve as the sale flavin in the metabolism of the rat. This flavin is able to serve as a completely adequate replacement for riboflavin in the metabolism of Wistar (Lambooy, 1961) and Sprague-Dawley rats (Yoon S. Kim et al, 1966) in terms of growth, survival, optimal physical appearance, and efficient utilization of food. Administration of 7-ethyl-8-methyl flavin to weanling rats as their only source of flavin permits a normal growth with a concomitant rapid and extensive loss of succinic dehydrogenase activity (SDH) from the liver, heart and kidney to within 24, 48, and 67% of the normal level, respectively, on day 42 following initiation of a 7-ethyl-8-methyl flavin diet. This result was essentially identical with that previously reported (Y.S. Kim and Lambooy, 1967). The purpose of the experiments described here is to study whether the decreased SDH activity in the tissue of rats is related to the metabolism of glucose and de novo biosynthesis of lipid from glucose in the liver of rats when D-glucose-$^{14}C$(U) is administered intraperitoneally to the rat maintaining SDH activity from liver, heart and kidney at 24, 48 and 67% of the normal level. This is also to study whether the total triglyceride and the total lipid content in the liver of rats is influenced by the loss of SDH activity in the liver of rats which have received 7-ethyl-8-methyl flavin. The present study shows that there was no significant difference in the total amount of $^{14}CO_2$ expired from D-glucose-$^{14}C$(U) through the respiration of rats which had received 7-ethyl-8-methyl flavin compared to control rats which received riboflavin, indicating that the matabolic rate of glucose in the tissues of rat receiving 7-ethyl-8-methyl flavin is similar to that of the control rats. However, compared to the control level only 50% of $^{14}C$ total lipids were incorporated by de novo biosynthesis from D-glucose-$^{14}C$(U) in the liver of rats receiving 7-ethyl-8-methyl flavin but the total content of triglyceride and total lipids in the liver of rats receiving 7-ethyl-8-methyl flavin were increased by 29 and 30% over the normal level. This may be due to the increased of lipid transport from the peripheral adipose tissue due to the decreased SDH activity in the liver of rats. 7-Ethyl-8-methyl flavin이 SDH 효소 활성에 미치는 영향에 대하여 Kim and Lambooy (1967)에 의해 보고된 바 있다. 즉 이 flavin 투여후 30일에 쥐 간장에서 SDH 효소 활성은 정상군의 해당조직 효소 활성치를 100%로 할때 23%로 떨어져 100일 까지 계속 20% 내외로 유지하여, 심장에서는 투여 30일에 64% 50일에 43% 100일에서 31% 내외였고, 신장에서는 30일에 72% 50일에 68% 100일에 56% 내외를 유지한다고 보고 하였다. 저자는 본 실험을 시작하기전에 Kim and Lambooy (1967)방법에 따라 쥐에 이 flavin을 투여한 후 42일에 SDH 효소 활성을 측정한바 간장에서 24% 심장에서 48% 신장에서 76%로 떨어졌으나, 그 쥐의 성장, 체중의 증가, 식이 섭취량 및 외모등이 riboflavin 투여군과 동일한 사실을 재확인 하였으며 이런 SDH 효소 활성을 유지하는 쥐에다 D-glucose $^{14}C$ (U)를 마리당 $55{\times}10^5$ dpm 씩 복강내 주입하고 이 쥐를 metabolic cage에 넣어 호흡을 통하여 나오는 총 $^{14}CO_2$의 배설량을 methylcellosolve:ethanolamine 용액 (2:1)에 포착시켜 정량한바 riboflavin 투여군에서는 평균 $257192{\pm}8630\;cpm$/3hrs/gm of body wt. 7-ethhyl-8-methyl flavin 군은 평균 $255426{\pm}1160\;cpm$/3hrs/gm of body wt. 로 두군의 총 $^{14}CO_2$ 배설량은 서로 같았다. 7-Ethyl-8-methyl flavin에 의하여 SDH 활성이 떨어졌음에도 총 $^{14}CO_2$ 배설량에 하등의 변동이 없는 이 두군에서 성장 및 체중증가, 식이 섭취량, 외모 등의 동일성으로 미루어보아 체내에 전체적으로 영향을 주는 대사장애는 없는 것으로 사려되나, 투여한 D-glucose $^{14}C$ (U)로부터 간장내 지방 de novo 생합성은 평균 $13080{\pm}420$ cpm per gm에서 $6595{\pm}400$ cpm per gm 으로 7-ethyl-8-methyl flavin 투여군에서 50%나 현저히 감소하였다. 간장지방내 $^{14}C$ 는 모두투여한 $^{14}C$ (U)로부터 합성된 것임으로 이 결과는 간장 조직내에서 SD H 활성 저하가 지방 de novo 생합성과 밀접한 관계가 있음을 시사해준다. 즉 SD H 활성이 떨어지면 Krebs cycle 저하를 초래하고 이것은 glucose로 부터 지방의 de novo 생합성을 떨어뜨리는 결과로 사려된다. 간장내 총 triglyceride 함량은 정상군에서 평균 $1.93{\pm}0.083gm%$이나 7-ethyl-8-methyl flavin 투여군에서는 $2.49{\pm}0.085gm%$로 29%가 증가하였으며 간장내 총지방함량 역시 정상군에서 평균 $4.53{\pm}0.299gm%$인데 비해 7-ethyl-8-methyl flavin 투여군에서는 $5.90{\pm}0.157gm%$로 정상군보다 30% 증가하였다. 이상 결과로 미루어 보아 7-ethyl-8-methyl flavin 투여로 간장에서 SDH 합성이 24%로 떨어지면 간장내 지방의 de novo 생합성은 50% 감소되나 총 triglyceride 함량은 정상군보다 29%, 총지방함량은 30% 증가하였다. 이는 아마도 체내 SDH 활성저하가 말초 지방조직으로부터 간장조직으로 지방산의 이동을 증가시키는 결과로 사려된다.

Dietary Induced depletion and Repletion of Pancreatic Enzymes in the Rat with Emphasis on Korean Dishes

김윤수,김명원,송정석,황석귀 생화학분자생물학회 1978 BMB Reports Vol.6 No.3

The primary objectives of the experiments described herein were to study the effect on the pancreatic enzyme activities -of a diet which was similarly prepared to Korean dishes and also to study the effect on the pancreatic enzyme activities of varying the proportion of fats to carbohydrates in the diet which keeps the diet isonitrogenous and isocalories. The data from the this experiment will be discussed in conjunction with previously published results conducted in our laboratory. The incidence of gastrointestinal patients in Korea could be adequately explained by diets prepared in similar composition to the Korean dishes. Rats fed with protein and lipid-depleted diet for four and six weeks were unable to respond to the stimulus of the diet at all which consists of high lipid, low protein and low carbohydrate. This result illustrates that the essential factor for stimulus of enzyme activity is protein in diet but not carbohydrate and fat. The effect of high proportion of fat to carbohydrate (94 : 6) in a isonitrogenous, isocaloric diet on pancreatic enzyme activities also was studied in rats and compared with the effect of normal isocaloric diet. When a diet which provided 57 cal/day was fed for four weeks, no effect of this diet on pancreatic chymotrypsinogen, trypsinogen and lipase was observed. However, pancreatic amylase was 61.5% after three weeks and 64% after four weeks, indicating that pancreatic amylase activity may be related when carbohydrate was limited but protein was normal in diet. It is therefore suggested that various dietary composition was related with the pancreatic enzyme activities and that one of main influential factors in diet on pancreatic enzyme is protein, but not fat.