• 대한약리학회지
• /
• 제32권2호
• /
• pp.151-158
• /
• 1996

Following the subcutaneous administration of $R(-)N^6-(2-phenylisopropyl)adenosine(600\;nmol/kg/hr)$ to rats for 1 week using t$Alzet^{\circledR}$ mini-osmotic pumps, $A_1$ adenosine receptor functions were determined using $[^3H]DPCPX$ binding, $[^{35}S]GTP_{\gamma}S$ binding, and adenylyl cyclase assays. $A_1$ adenosine receptor binding and the inhibition of adenylyl cyclase activity by PIA was not altered in cerebrocortical membranes prepared from PIA-treated rats. However, there was a significant decrease in the $A_1$ adenosine receptor-mediated stimulation of $[^{35}S]GTP_{\gamma}S$ binding to cerebrocortical membranes prepared from PIA-treated rats(22.0% decrease in basal activity; 19.7% decrease in maximal activity). These results suggest that the desensitization of $A_1$ adenosine receptors following chronic administration involves agonist-induced uncoupling of the receptors from G proteins rather than alteration of $A_1$ adenosine receptor molecules. It is also suggested that the determination of stimulation of $[^{35}S]GTP_{\gamma}S$ binding to G proteins is a suitable tool in studying the receptor regulation including desensitization

• 한국양식학회지
• /
• 제10권1호
• /
• pp.1-7
• /
• 1997

남해 가두리 양식장에서 사육중인 전장 16.3~20.1 cm 크기의 돌돔 표피에 Monogenoidae, Benedenia sp. 가 10~31마리 기생되었다. 이 기생충의 감염률과 상대 감염밀도는 100%, 16.5 이었다. 기생 부위는 몸통 표피에 81.8%, 꼬리 부분에 16.5%, 기타 부위에 1.6%이었다. 기생된 부위는 출혈과 함께 점액이 다량 분비되었고, 궤양도 형성되었다. 이 기생충은 포르말린 250 ppm에서 10분, 200 ppm에서 20분, 150 ppm에서 20분만에 탈락 폐사되었으며, 담수욕 처리에서는 담수 100%에서 9분, 70%에서 20분만에 구제되었다. 기생충 구제를 위한 포르말린 처리에서 포르말린 독성에 의한 돌돔 폐사는 없었다. 그러나 담수 100% 시험구에서 중증어(기생충 대량 감염에 의한 점액 분비, 출혈, 궤양) 1마리가 폐사되었는데 이것은 삼투압조절 상실 때문이라고 여겨진다.

• Childhood Kidney Diseases
• /
• 제20권1호
• /
• pp.11-17
• /
• 2016

Appropriate control of diet and water intake is important for maintaining normal blood pressure, fluid and electrolyte homeostasis in the body. It is relatively understood that the amount of sodium and potassium intake directly affects blood pressure and regulates ion transporters; Na and K channel functions in the kidney. However, little is known about whether diet and water intake regulates Aquaporin (AQP) function. AQPs, a family of aquaporin proteins with different types being expressed in different tissues, are important for water absorption by the cell. Water reabsorption is a passive process driven by osmotic gradient and water permeability is critical for this process. In most of the nephron, however, water reabsorption is unregulated and coupled to solute reabsorption, such as AQP1 mediated water absorption in the proximal tubule. AQP2 is the only water channel founded so far that can be regulated by hormones in the kidney. AQP2 expressed in the apical membrane of the principal cells in the collecting tubule can be regulated by vasopressin (antidiuretic hormone) controlling the final volume of urine excretion. When vasopressin binds to its receptor on the collecting duct cells, it stimulates the translocation of AQP2 to the membrane, leading to increased water absorption via this AQP2 water channel. However, some studies also indicated that the AQP2 is also been regulated by vasopressin independent mechanism. This review is focused on the regulation of AQP2 by diet and the amount of water intake on salt and water homeostasis.

• The Korean Journal of Pain
• /
• 제34권4호
• /
• pp.405-416
• /
• 2021

Background: This study investigated the effect of intrathecal Sec-O-glucosylhamaudol (SOG) on the p38/c-Jun N-terminal kinase (JNK) signaling pathways, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-related inflammatory responses, and autophagy in a spinal nerve ligation (SNL)-induced neuropathic pain model. Methods: The continuous administration of intrathecal SOG via an osmotic pump was performed on male Sprague-Dawley rats (n = 50) with SNL-induced neuropathic pain. Rats were randomized into four groups after the 7th day following SNL and treated for 2 weeks as follows (each n = 10): Group S, sham-operated; Group D, 70% dimethylsulfoxide; Group SOG96, SOG at 96 ㎍/day; and Group SOG192, SOG at 192 ㎍/day. The paw withdrawal threshold (PWT) test was performed to assess neuropathic pain. Western blotting of the spinal cord (L5) was performed to measure changes in the expression of signaling pathway components, cytokines, and autophagy. Additional studies with naloxone challenge (n = 10) and cells were carried out to evaluate the potential mechanisms underlying the effects of SOG. Results: Continuous intrathecal SOG administration increased the PWT with p38/JNK mitogen-activated protein kinase (MAPK) pathway and NF-κB signaling pathway inhibition, which induced a reduction in proinflammatory cytokines with the concomitant downregulation of autophagy. Conclusions: SOG alleviates mechanical allodynia, and its mechanism is thought to be related to the regulation of p38/JNK MAPK and NF-κB signaling pathways, associated with autophagy during neuroinflammatory processes after SNL.

• Journal of Ecology and Environment
• /
• 제47권3호
• /
• pp.85-102
• /
• 2023

Background: Ecophysiological characteristics of Rosa rugosa were analyzed under different environmental factors from May to October 2022. Photosynthesis, chlorophyll fluorescence, chlorophyll content, leaf water content (LWC), osmolality, carbohydrate content, and total ion content were measured to compare the physiological characteristics of R. rugosa at two study sites (i.e., in large pots and in the Goraebul coastal sand dune area). Results: When R. rugosa was exposed to high temperatures, photosynthetic parameters including net photosynthetic rate (P_N) and stomatal conductance (g_s) in both experiment areas declined. In addition, severe photoinhibition occurs when R. rugosa is continuously exposed to high photosynthetically active radiation (PAR), and because of this, relatively low Y(II) (i.e., the quantum yield of photochemical energy conversion in photosystem II [PSII]) and high Y(NO) (i.e., the quantum yield of non-regulated, non-photochemical energy loss in PSII) in the R. rugosa of the pot were observed. As the high Y(NPQ) (i.e., the quantum yield of regulated non-photochemical energy loss in PSII) of R. rugosa in the coastal sand dune, they dissipated the excessed photon energy through the non-photochemical quenching (NPQ) mechanism when they were exposed to relatively low PAR and low temperature. Rosa rugosa in the coastal sand dune has higher chlorophyll a and carotenoid content. The high chlorophyll a + b and low chlorophyll a/b ratios seemed to optimize light absorption in response to low PAR. High carotenoid content played an important role in NPQ. As a part of the osmotic regulation in response to low LWCs, R. rugosa exposed to high temperatures and continuously high PAR used soluble carbohydrates and ions to maintain high osmolality. Conclusions: We found that F_v/F_m was lower in the potted plants than in the coastal sand dune plants, indicating the vulnerability of R. rugosa to high temperatures and PAR levels. We expect that the suitable habitat range for R. rugosa will shrink and move to north under climate change conditions.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권3호
• /
• pp.355-365
• /
• 2010

The aim of this study was to investigate the effect of supplemental recombinant bovine somatotropin (rbST) and cooling with misters and fans on renal function in relation to regulation of body fluids in different stages of lactation in crossbred Holstein cattle. Ten, 87.5% crossbred Holstein cattle were divided into two groups of 5 animals each, housing in a normal shaded barn (NS) and in a shaded barn with a mister-fans cooling system (MF). The experiment in each group was divided into 3 phases, early- (Day 75 postpartum), mid- (Day 135 postpartum), and late stage of lactation (Day 195 postpartum). The pre-treatment study was conducted on the starting day of each stage of lactation and the treatment study was performed after the end of the pre-treatment, during which the animal was injected with 500 mg of rbST (POSILAC) every 14 days for three times. During the study, ambient temperature at the hottest period daily in the MF barn was significantly lower, while relative humidity was higher than that of the NS barn. The temperature humidity index (THI) in both barns ranged from 79-85 throughout the periods of study. Cows in the MF barn showed a lower rectal temperature and respiration rate as compared with cows in the NS barn. The effect of rbST administration increased both rectal temperature and respiration rates of cows housed in either the NS or MF barn. Milk yield significantly increased in cows treated with rbST in all stages of lactation. Increases in mammary blood flow, accompanied by increases of total body water (TBW), extracellular fluid (ECF), blood volume (BV) and plasma volume (PV), were observed in both groups of cows receiving rbST in all stages of lactation. No alterations of renal blood flow and glomerular filtration rate were observed in cows receiving rbST, but decreases in urinary excretion and fractional excretion of sodium, potassium and chloride ions appeared to correlate with reduction in the rate of urine flow and osmolar clearance during rbST administration. These results suggest that the effect of rbST supplementation to cows housed either in NS or MF barns on body fluid volume expansion is attributable to changes in the rate of electrolyte excretion by the kidney. The increased availability of renal tubular reabsorption of sodium, potassium and chloride ions during rbST treatment was a major factor in retaining body water through its colligative properties in exerting formation of an osmotic force mechanism.

• Journal of Plant Biotechnology
• /
• 제35권4호
• /
• pp.307-316
• /
• 2008

식물에서 전이인자를 이용한 삽입 변이체의 유전자 기능분석 연구가 최근 가장 활발하게 이루어지고 있다. 본 연구에서는 동진벼의 Ac/Ds 삽입 변이체인 F2 세대 30,000 계통을 이용하여 고염과 저온에 민감한 계통과 내성이 있는 계통을 대량 스크리닝을 통해 선발하였다. 첫 번째 스크리닝에서 선발한 212 계통을 Southern blot 분석을 통해 Ds의 삽입여부 및 copy 수를 꽉인하고 표현형과 비교하여 고염과 저온에서 총 19 계통을 선발하였고, 이 중 copy 수가 하나인 계통은 13 계통이었다. 선발한 계통을 FSTs 분석을 통해 Ds의 삽입위치 및 knock-out유전자를 확인하고 염기서열 정보를 이용하여 벼 전체 염기서열 정보와 상동성 비교분석 결과 세포의 신호전달 과정과 조절 관여하는 유전자 그룹인 transpoter, protease family protein and apical meristem family protein, 삼투압조절에 관여하는 유전자 그룹인 heat shock potein, O-methyltransferase, glyceraldehyde-3-phosphate dehydrogenase and drought stress Induce protein 그리고 식물의 소포유통(vesicle trafficking)에 관여하는 유전자 SYP 5 family protein로 구분할 수 있었다. 선발된 19개 유전자의 발현 분석을 위해 9종류 비생물학적 스트레스 하에서 RT-PCR을 수행한 결과 이들 knock-out 유전자는 비생물학적 스트레스에 각각 다른 발현 패턴을 보였다. 이 연구의 결과는 삽입 변이체를 통한 유전자의 기능분석에 있어서 비생물학적인 스트레스의 응답 반응계에 관여하는 유전자를 연구하는데 유용할 것이라고 생각된다.

• 생명과학회지
• /
• 제22권10호
• /
• pp.1359-1370
• /
• 2012

애기장대에서 AtERF71/HRE2는 핵에서 전사인자로 작용하여 하위 유전자의 발현을 증가시키는 역할을 수행함으로써 저산소와 삼투 스트레스 반응에 관여할 것으로 여겨지는 유전자이다. 본 연구에서는 AtERF71/HRE2에 의해 직, 간접적으로 발현이 조절되는 하위 유전자를 알아보기 위해 AtERF71/HRE2 과발현체를 대상으로 마이크로어레이 실험을 수행하였다. 야생형에 비해 AtERF71/HRE2 과발현체에서 발현이 2배 이상 증가한 기능이 알려진 유전자는 AtERF71/HRE2 자신을 제외하고 161개였다. 161개 유전자 중 전사인자와 DNA-결합 단백질 등과 같은 전사조절자가 24개로 확인되어, AtERF71/HRE2는 하위 전사조절 유전자의 발현 조절을 통해 더 많은 유전자의 발현을 조절하는 상위 전사인자로서의 기능을 가질 것으로 추정되었다. 161개 유전자 중 15개 유전자를 대상으로 RT-PCR을 수행하여 마이크로어레이 결과의 신뢰성을 검증하였다. Genevestigator 데이터베이스 분석 결과, 161개 유전자 중 51개 유전자는 저산소 및 삼투 스트레스에 의해 발현이 증가하는 것으로 확인되었다. RT-PCR 분석 결과 AtERF71/HRE2 과발현체에서 발현이 증가한 15개 유전자 중 3개 유전자가 저산소에 의해 발현이 증가하였고, 다른 3개 유전자가 삼투 스트레스에 의해 발현이 증가하였으며, 이러한 결과는 이들 유전자가 AtERF71/HRE2에 의해 매개되는 저산소 또는 고염 스트레스 신호전달의 하위 유전자일 수 있음을 의미한다. 또한 본 연구의 마이크로어레이 분석 결과는 AtERF71/HRE2가 저산소 및 삼투 스트레스 반응뿐만 아니라 다른 환경 스트레스 반응과 식물 발달 조절에도 관여할 수 있음을 시사한다.

• The Korean Journal of Physiology
• /
• 제27권1호
• /
• pp.13-25
• /
• 1993

To study the regulation of amniotic fluid volume and electrolyte concentration by the Membranes surrounding the amniotic fluid, the rate of $Li^+$ disappearance from amniotic sac of expired fetuses were examined while increasing the amniotic volume and osmolarity in rabbits. After intraamniotic injection of 1 ml isosmotic saline (about 20% of the amniotic fluid volume) containing 15 mM LiCl and 0.5 g/L Censored, the time courses of $Li^+$ and Censored disappearance were determined. From there the $Li^+$ clearance through the extrafetal routes was estimated and compared with that obtained from living fetuses. The volume, $Na^+$ concentration and osmolarity of amniotic fluid were measured and their relationships with $Li^+$ disappearance were evaluated. The fellowing results were obtained: 1. The rate of disappearance from amniotic fluid of living fetuses during the first 30 minutes was strikingly higher for $Li^+$ than for Censored, suggesting that extrafetal routes exist. At 60 and 90 minutes, however, the disappearance rate of $Li^+$ was less than that of Censored, suggesting the possibility of $Li^+$ reentry through fetal urination. 2. The disappearance of $Li^+$ from the amniotic fluid of the expired fetus was substantial, although lower than that of living fetuses, throughout the experimental period. 3. The $Na^+$ concentration and the osmolarity of the amniotic fluid of expired fetus measured 30 minutes after an intraamniotic injection of isoosmotic saline showed wide variation, but thereafter they changed gradually towards the normal extracellular fluid level. 4. When the amniotic fluid was iso- or hyposmolar, the rate of $Li^+$ disappearance from the amniotic fluid of the expired fetuses showed little variation. However, when the amniotic fluid was hyperosmolar, the rate at 30 minutes was markedly lower than those of isosmotic or hyposmotic amniotic fluid. At 90 minutes, the rate of $Li^+$ disappearance in hyperosmolar fluid reached a similar level to the rate in isosmolar fluid. 5. The intraamniotic injection of 400 mOsm/L saline solution decreased the disappearance rate of $Li^+$ from expired fetuses, while the injection of mannitol into the maternal vein induced no significant change. From these results it is concluded that: 1) a significant amount of $Li^+$ may leave the amniotic fluid via filtration through the membranes surrounding the amniotic fluid, 2) during hyperosmolar challenge to amniotic fluid, osmotic bulk flow might counteract the filterable loss, and 3) $Li^+$ disappearance might continue even after the volume and osmolarity of the amniotic fluid have recovered to control values.

• 한국토양비료학회지
• /
• 제37권2호
• /
• pp.91-96
• /
• 2004

집약적인 시설재배 농업에서 화학비료와 퇴비의 연용과 과다한 사용은 용탈현상이 제한되어 있는 시설재배 토양의 염류집적현상을 쉽게 유발시키고 있다. 토양중의 염류집적에 따른 수분 흡수의 어려움을 극복하기 위하여 식물은 여러 가지의 무기 및 유기용질을 체내에 축적하는데, 특히 토양 중에 그 함량이 높아 쉽게 이용할 수 있는 $NO_3$를 삼투압 조절물질로 흡수 축적하는 것으로 결론지을 수 있다. 안전농산물의 생산 측면에서 특히 시설재배 신선야채류의 $NO_3$ 축적을 줄이기 위한 노력이 요구되고 있으며, 이를 이해서는 과다한 시비의 지양과 광조건의 개선이 필요하며 이에 더하여 토양 염류집적을 줄일 수 있는 토양 관리 및 시비 방법들이 심각하게 고려되어야 할 것이다.