• 생명과학회지
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• 제34권6호
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• pp.426-433
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• 2024

식물이 가장 쉽게 노출되는 환경적 위험은 수분 스트레스이다. Abscisic acid (ABA)는 환경 스트레스에 적응하기 위해 식물에서 생성되는 식물 호르몬이다. 식물에서 기공의 가장 중요한 역할은 광합성 활성에 크게 영향을 주는 CO₂를 흡수하여 슈크로스의 합성을 활발하게 유도하는 것이다. 또한 기공은 증산작용을 통해 H₂O를 방출하는 통로이며, 식물의 뿌리가 토양에서 물과 무기 물질을 지속적으로 흡수할 수 있도록 수분퍼텐셜의 기울기를 형성하는 기능을 한다. 식물은 수분 스트레스 환경에 노출되면, 기공을 닫아 수분 손실을 최소화하는 메커니즘을 가진다. 환경에 따른 기공 닫힘 메커니즘들과 관련하여 가장 잘 밝혀진 가설은 수분 스트레스에 대한 기공 반응이다. 식물이 충분한 수분을 공급받은 상태일 때, 기공은 일주기 리듬에 따라 낮에는 열리고 밤에는 닫힌다. 또한 세포간극 안에 CO₂ 농도가 증가하면 기공이 닫힌다. 그러나 일주기 리듬과 세포간극 안의 CO₂ 농도 증가로 인한 기공 닫힘 메커니즘은 명확하게 알려져 있지 않다. 식물이 수분 스트레스에 놓이면, 공변세포 세포질의 ABA 농도 증가는 동일한 세포질 내에 Ca²⁺ 농도 증가를 유도하여 원형질막에서 탈분극이 발생한다. 그 결과, 액포막에 있는 외향성 K⁺-채널과 느린 음이온 채널들인 SLAC1, SLAH3가 활성화되어 K⁺, Cl^-, 그리고 malate^2-를 방출하여 기공이 닫히는 것으로 알려져 있다. 따라서 본 논문은 수분 스트레스로 인한 기공 닫힘 메커니즘에 대하여 조사하였다.

• Applied Microscopy
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• 제12권1호
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• pp.57-68
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• 1982

Cyclical changes in the fine structures of endometrial stroma of guinea pig during the estrous cycle were studied by electron microscopy. Cytochemical studies were made in order to investigate the ultrastructural localization of the acid phosphatase,alkaline phosphatase and ATPase in these cells. The results obtained are as follows: 1. During estrus collagen fibers were most abundant in the stroma. The stromal cells showed increases in the number of several cytoplasmic organelles, especially the rough endoplasmic reticulum was significantly increased and the structures were greatly differentiated. 2. Many cytoplasmic processes and cell debris have been distributed in the stroma of metestrus. The distributions were increased and degenerated mitochondria were observed during diestrus. 3. Cytochemical studies indicated that during metestrus and diestrus acid phosphatase activities were localized in the degenerating collagen fibers. Alkaline phosphatase activities were weak in the collegen fibers during proestrus and estrus which intense activities were localized around the cell membrane during metestrus and diestrus. ATPase activities were present on the cell membrane and intercellular space of stromal cell during proestrus and estrus.

• Toxicological Research
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• 제14권3호
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• pp.333-339
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• 1998

Sambutoxin, a newly purified mycotoxin in Koea, caused hemorrhage in the stomach and intestine of rats. To elucidate the mechanism of hemorrhage, effects of sambutoxin on rabbit platelet aggregation were investigated. First of all, the effects of sambutoxin on the platelet aggregation response and ATP release from platelet by various appregating factors were investigated. And then the role of $Ca^{2+}$ on the platelet aggregation was investigated by flow cytometer. Finally, morphological effect of sambutoxin on platelet ultrastructure was examined by transmission electron microscope. Sambutoxin inhibited aggregation induced by ADP, collagen, thrombin, and arachidonic acid and decreased platelet activating factor-induced disaggregation time in a dose dependent manner. Sambutoxin also decreased thrombin and arachidonic acid-induced ATP release, but increased all factors induced $Ca^{2+}$ release. Sambutoxin showed severe ultrastructural changes of platelet such as appearance of disorganization debri of cellular organelle in intercellular space. Our results indicate that sambutoxin inhibitis rabbit platelet aggregation, and it may be party due to the decrease of ATP release. However, it is not clear whether the antiaggregating effect of sambutoxin is related to $Ca^{2+}$ increase.

• 대한한방내과학회지
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• 제17권1호
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• pp.278-289
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• 1996

This paper aims to probe the effect of Rosa rugosa, Thunbergii which streptozotocin induced hyperglycemic rats was examined by glucose contents, body weight, kidney weight and histological observation. The results obtained were as follows: 1. The glucose level is decreased in the adminstered group of the Rosa rugosa compared with control group. These effects are in order named root group, stem group and leaf group group. BUN is increased fold of 1.52 in the control group compared with normal group, but the administered group of Rosa rugosa are decreased., in order named leaf group, root group and stem group. 2. The kidney hypertrophy to body weight is the higest in the control group compared with the other group in rats, and glucose contents are in order named stem group, leaf group and root group. 3. The loss of body weight is the highest in the control group, and the loss is in order named stem group, leaf group and root group in rats. 4. In histological observations, pancreatic pancreatic islets of control group shows disrupted or condensed nuclei, and the intercellular space between acini are enlarged. In the experimental group, histological damages of the acini and pancreatic islet are recovered compared with control group. Thes results suggest that the extracts of Rosa rugosa are effected to diabetes mellitus, root extract correlated with the function of kidney, and leaf extract is decreased plasma glucose.

• 한국농림기상학회지
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• 제5권4호
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• pp.218-225
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• 2003

본 실험은사과원의 위치에 따라 국지기후조건이 다양함을 보여주었으며, 이와 같이 다양한 기후환경은 과실의 품질에 직간접적으로 많은 영향을 미치고 있는 것으로 조사되었다. 즉, 당함량과 anthocyanin 함량은 8월의 평균기온에 따라 다른 것으로 나타났으며 일정한 상관관계를 가지고 있었다. 또한 4월에서 8월까지의 평균기온과 과육의 경도 사이에 일정한 상관이 인정되었으며, 4월에서 8월까지의 최고기온과 Hunter a값 사이에도 상관관계가 인정되었다. 이러한 기후조건의 범위는 세포조직학적 특성에도 영향을 미쳤으며, 온도는 과피층 세포의 수와 크기에 영향을 주었다. 따라서, 사과 주산지의 과실 품질은 기후의 영향을 크게 받아 매우 다양하게 나타나는 것으로 조사되었다.

• 대한의생명과학회지
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• 제7권2호
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• pp.71-77
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• 2001

To evaluate the effect of occlusive skin on the activity of cutaneous oxygen free radical metabolizing enzymes in rats, the dorsal skin was covered with closed glass chamber shaped petri dish, 46 mm in diameter and 10 mm in height and sealed by an adhesive. Five day-occluded group showed more increased activity of xanthine oxidase (XO) than that of control, and the activity of five day-occluded group was higher than that of ten day-occluded group. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were significantly higher in ten day-occluded group than in control or five day-occluded group. All the more, five day-occluded group showed the decreasing tendency of SOD and GPx activities compared to those of control. On the other hand, the cerrous perhydroxide deposits were observed in the intercellular space of the stratum basale in five day-occluded group under the electronic microscope using a cytochemistry method. Futhermore, the degree of cerrous perhydroxide reaction was lower in ten day-occluded group than in five day-occluded group. In conclusion, the increased XO activity and the decreased SOD and GPx activities are likely to responsible far the accumulation of $H_2O_2$ in five day-occluded group.

• Journal of the Korean Wood Science and Technology
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• 제16권2호
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• pp.42-49
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• 1988

Anatomical characteristics on abnormal type of bisected compression woods and light colored wood intervened between these dark colored compression woods on under part and their respective opposite woods on upper parts of cross section in Pinus densiflora S. et Z. stem were compared through optical microscopic investigation. and the obtained results were summarized as follows: 1. Tracheid length increased linearly as the number of rings from the pith increases in all investigated parts, but increasing tendency in tracheid length was similar within bisected two compression woods and their opposite woods. 2. Tracheids were the shortest in bisected two compression woods and tracheid length in intervened wood between these two compression woods was longer than in compression woods but shorter than in the opposite woods. 3. Bisected two compression woods and intervened wood between these two compression woods revealed similar features in tracheid transition from springwood to summerwood, intercellular space, tracheid entanglement, and cross sectional view of tracheid. but spiral check was observed only in these two compression woods, therefore the intervened wood between these two compression woods disclosed anatomical characteristics similar to, not typical of, compression woods.

• 대한한방내과학회지
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• 제25권3호
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• pp.508-517
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• 2004

This study was performed to investigate the effectiveness of Hangryunhaedocktang (HHT) on epidermal damages induced by allergic contact dermatitis (ACD). The sensitization were caused by one application of $25{\mu}l$ of 5% 2,4-dinitroch1orobenzene (DNCB) onto a back-lumbar skin of BALB/c mice. 2 weeks later, ACD was elicitated with $4{\mu}l$ of 2.5% DNCB and then mice were given HHT extract in doses of 3.3ml/kg/day, for 72 hours. The ACD induced epidermal damages in HHT treated ACD mice was more mitigated than non-treated ACD elicited mice. The features related with epidermal damage such as epidermal hyperplasia, infiltration of inflammatory cells, increase of nuclear shrinkages and vacuolation, and enlargement of intercellular space softened. And the distribution of soybean agglutinin (SBA) positive reaction in stratum spinosum (SS) and stratum basale (SB) were similarly maintained in a normal configuration. The numerical decrease of BrdU, TUNEL, and Fas positive cells observed were prominent in SB. Results suggest a benefit role for HHT in mitigating epidermal damages in mice with allergic contact dermatitis.

• 한국식품영양과학회지
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• 제22권5호
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• pp.611-616
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• 1993

본 연구는 감과실의 성숙과 연화중에 일어나는 세포벽분해효소의 활성, 펙틴 및 조직의 변화를 조사하였다. Polygalacturonase와 ${\beta}-galactosidase$의 활성은 미숙과실에 없었으나 완숙 감과실에서 각각 55.1, 21.79unit/100g-fr. wt.이었고 연시에서는 각각 206.70, 380.23unit/100g-fr, wt으로 증가하였다. 펙틴질의 변화는 총 펙틴과 불용성 펙틴은 성숙중에 증가하였으나 연시에서는 현저히 감소하였으며, 반면에 수용성 펙틴은 성숙과 연화중에 증가하였다. 감과실의 성숙주엥 간극의 발달과 더불어 middel lamella의 용해현상이 일어났으며 연시에서는 세포가 분리되었다.

• 한국식품영양과학회지
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• 제25권3호
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• pp.470-477
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• 1996

This study was intended to observe the changes of pectic substances and enzyme activities, texture, microstructure of anchovy added kimchi during fermentation for 4 weeks at 4$^{\circ}C$. Content of alcohol insoluble solid(AIS) and HCl soluble pectin(HClSP) were decreased, whereas content of hot water soluble pectin(HWSP) was increased during fermentation. Content of HClSP was higher and HWSP was lower in anchovy added kimchi than control. Activity of pectinesterase(PE) was decreased, whereas activity of polygalacturonase(PG) was increased during fermentation. In anchovy added kimchi, PG activity was lower than control. Changes in microstructure of Chinese cabbage and kimchi during fermentation was lower than control. Changes in microstructure of Chinese cabbage and kimchi during fermentation was observed ; in the raw cabbage, parenchyma cells, intercellular space and middle lamella were clearly shown. But in salted cabbage, middle lamella became separated. In the late stage of fermentation, parenchyma cell walls were wrinkled and collapsed. Puncture forces of kimchi were decreased, whereas cutting forces of kimchi were increased as fermentation proceeded. The firmness was slightly higher in anchovy added kimchi than control at the late stage fermentation, which may be explained by the PG activity.