• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.327-335
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• 2009

The aim of this study was to determine whether losartan, an angiotensin II (Ang II) type 1 ($AT_1$) receptor could influence the CA release from the isolated perfused model of the rat adrenal medulla. Losartan (5${\sim}$50 ${\mu}$M) perfused into an adrenal vein for 90 min produced dose- and time-dependent inhibition of the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM, a direct membrane depolarizer), DMPP (100 ${\mu}$M) and McN-A-343 (100 ${\mu}$M). Losartan failed to affect basal CA output. Furthermore, in adrenal glands loaded with losartan (15 ${\mu}$M) for 90 min, the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}$M, an activator of L-type $Ca^{2+}$ channels), cyclopiazonic acid (10 ${\mu}$M, an inhibitor of cytoplasmic $Ca^{2+}$ -ATPase), veratridine (100 ${\mu}$M, an activator of $Na^+$ channels), and Ang II (100 nM) were markedly inhibited. However, at high concentrations (150${\sim}$300 ${\mu}$M), losartan rather enhanced the CA secretion evoked by ACh. Collectively, these experimental results suggest that losartan at low concentrations inhibits the CA secretion evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) as well as by membrane depolarization from the rat adrenal medulla, but at high concentration it rather inhibits ACh-evoked CA secretion. It seems that losartan has a dual action, acting as both agonist and antagonist to nicotinic receptors of the rat adrenal medulla, which might be dependent on the concentration. It is also thought that this inhibitory effect of losartan may be mediated by blocking the influx of both $Na^+$ and $Ca^{2+}$ into the rat adrenomedullary chromaffin cells as well as by inhibiting the $Ca^{2+}$ release from the cytoplasmic calcium store, which is thought to be relevant to the $AT_1$ receptor blockade, in addition to its enhancement of the CA release.

• The Korean Journal of Physiology and Pharmacology
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• 제8권4호
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• pp.227-235
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• 2004

The aim of the present study was to examine the effect of leptin on CA release from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. Leptin $(1{\sim}100\;ng/ml)$, when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced a dose-dependently the secretory responses of CA evoked by ACh $(5.32{\times}10^{-3}\;M)$, DMPP $(10^{-4}\;M)$ and McN-A-343 $(10^{-4}\;M)$, although it alone has weak effect on CA secretion. However, it did not affect the CA secretion evoked by excess $K^+\;(5.6{\times}10^{-2}\;M)$. Leptin alone produced a weak secretory response of the CA. Moreover, leptin (10 ng/ml) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$ ATPase. However, in the presence of U0126 $(1\;{\mu}M)$, an inhibitor of mitogen-activated protein kinase (MAPK), leptin no longer enhanced the CA secretion evoked by ACh and DMPP. Furthermore, in the presence of anti-leptin (10 ng/ml), an antagonist of Ob receptor, leptin (10 ng/ml) also no longer potentiated the CA secretory responses evoked by DMPP and Bay-K-8644. Collectively, these experimental results suggest that leptin enhances the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors), but does not that by membrane depolarization. It seems that this enhanced effect of leptin may be mediated by activation of U0126-sensitive MAPK through the leptin receptors, which is probably relevant to the activation of the dihydropyridine L-type $Ca^{2+}$ channels located on the rat adrenomedullary chromaffin cells.

• Biomolecules & Therapeutics
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• 제15권2호
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• pp.108-117
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• 2007

The aim of the present study was to investigate the effect of glibenclamide, a hypoglycemic sulfonylurea, which selectively blocks ATP-sensitive K$^+$ channels, on secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal glands. The perfusion of glibenclamide (1.0 mM) into an adrenal vein for 90 min produced time-dependently enhanced the CA secretory responses evoked by ACh (5.32 mM), high K$^+$ (a direct membrane depolarizer, 56 mM), DMPP (a selective neuronal nicotinic receptor agonist, 100 ${\mu}$M for 2 min), McN-A-343 (a selective muscarinic M1 receptor agonist, 100 ${\mu}$M for 2 min), Bay-K-8644 (an activator of L-type dihydropyridine Ca$^{2+}$ channels, 10 ${\mu}$M for 4 min) and cyclopiazonic acid (an activator of cytoplasmic Ca$^{2+}$-ATPase, 10 ${\mu}$M for 4 min). In adrenal glands simultaneously preloaded with glibenclamide (1.0 mM) and nicorandil (a selective opener of ATP-sensitive K$^+$ channels, 1.0 mM), the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered to the considerable extent of the control release in comparison with that of glibenclamide-treatment only. Taken together, the present study demonstrates that glibenclamide enhances the adrenal CA secretion in response to stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization from the isolated perfused rat adrenal glands. It seems that this facilitatory effect of glibenclamide may be mediated by enhancement of both Ca$^{2+}$ influx and the Ca$^{2+}$ release from intracellular store through the blockade of K$_{ATP}$ channels in the rat adrenomedullary chromaffin cells. These results suggest that glibenclamide-sensitive K$_{ATP}$ channels may play a regulatory role in the rat adrenomedullary CA secretion.

• 한국식품과학회지
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• 제25권2호
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• pp.185-190
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• 1993

담수산 틸라피아를 하루 $5%_{\circ}$씩 해수농도를 높여 1주일에 걸쳐 $32%_{\circ}$ 해수에 순화시켜, 이때를 기준(0주)으로하여 1주일 간격으로 염세포의 발달, 근육의 물성 및 미량원소의 변화와 더불어 근원심유의 ATPase 활성 및 열안정성에 대한 변화를 알아보았다. 아가미의 염세포는 해수순화와 더불어 점진적으로 갯수가 늘어나고 크기가 커져 순화 3주째에 발달이 완료되었다. 근육의 절단 및 압착강도도 해수순화에 따라 현저히 증가하여 근육의 물성변화를 보였으며, 일부 미량원소 (Mg, Na, K)도 뚜렷한 측적을 나타내었다. 근원섬유 ATPase 활성은 해수순화와 더불어 담수산의 것에 비해 유의차를 보이며 증가하였다. 근육중의 미량원소의 증가와도 관련이 있을 것으로 보이는 근원섬유 ATPase 활성증가는 결국 근육중의 ATP 분해를 촉진하여 근수축을 신속히 유도, 근육의 탄력을 증대시킴으로써 식감이 개선되는 것으로 추측되었다. 한편, 근원섬유의 열안정성은 해수순화에 의해 현저히 저하되었다.

• Tuberculosis and Respiratory Diseases
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• 제85권2호
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• pp.147-154
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• 2022

Background: The expression of calcium signaling pathway molecules is altered in various carcinomas, which are related to the proliferation and altered characteristics of cancer cells. However, changes in calcium signaling in anti-cancer drug-resistant cells (bearing a T790M mutation in epidermal growth factor receptor [EGFR]) remain unclear. Methods: Afatinib-mediated changes in the level of store-operated Ca²⁺ entry (SOCE)-related proteins and intracellular Ca²⁺ level in non-small cell lung cancer cells with T790M mutation in the EGFR gene were analyzed using western blot and ratiometric assays, respectively. Afatinib-mediated autophagic flux was evaluated by measuring the cleavage of LC3B-II. Flow cytometry and cell proliferation assays were conducted to assess cell apoptosis and proliferation. Results: The levels of SOCE-mediating proteins (ORAI calcium release-activated calcium modulator 1 [ORAI1], stromal interaction molecule 1 [STIM1], and sarco/endoplasmic reticulum Ca²⁺ ATPase [SERCA2]) decreased after afatinib treatment in non-small cell lung cancer cells, whereas the levels of SOCE-related proteins did not change in gefitinib-resistant non-small cell lung cancer cells (PC-9/GR; bearing a T790M mutation in EGFR). Notably, the expression level of SOCE-related proteins in PC-9/GR cells was reduced also responding to afatinib in the absence of extracellular Ca²⁺. Moreover, extracellular Ca²⁺ influx through the SOCE was significantly reduced in PC-9 cells pre-treated with afatinib than in the control group. Additionally, afatinib was found to decrease the level of SOCE-related proteins through autophagic degradation, and the proliferation of PC-9GR cells was significantly inhibited by a lack of extracellular Ca²⁺. Conclusion: Extracellular Ca²⁺ plays important role in afatinib-mediated autophagic degradation of SOCE-related proteins in cells with T790M mutation in the EGFR gene and extracellular Ca²⁺ is essential for determining anti-cancer drug efficacy.

• 동의생리병리학회지
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• 제27권1호
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• pp.112-117
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• 2013

We studied the modulation of pacemaker activities by Samchulkunbi-tang (SCKB) in cultured interstitial cells of Cajal (ICC) from murine small intestine with the whole-cell patch-clamp technique. Externally applied SCKB produced membrane depolarization in the current-clamp mode. The pretreatment with $Ca^{2+}$-free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker potentials and suppressed the SCKB-induced action. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by SCKB. However, the application of niflumic acid (a chloride channel blocker) did not inhibit the generation of pacemaker potentials by SCKB. In addition, the membrane depolarizations were inhibited by not only GDP-${\beta}$-S, which permanently binds G-binding proteins, but also U-73122, an active phospholipase C inhibitor. These results suggest that SCKB modulates the pacemaker activities by nonselective cation channels and external $Ca^{2+}$ influx and internal $Ca^{2+}$ release via G-protein and phospholipase C-dependent mechanism. Therefore, the ICC are targets for SCKB and their interaction can affect intestinal motility.

• 대한약침학회지
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• 제16권4호
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• pp.36-42
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• 2013

Objectives: Shengmaisan (SMS) is a traditional Chinese medicine prescription widely used for the treatment of diverse organs in Korea. The interstitial cells of Cajal (ICCs) are pacemaker cells that play an important role in the generation of coordinated gastrointestinal (GI) motility. We have aimed to investigate the effects of SMS in the ICCs in the mouse small intestine. Methods: To dissociate the ICCs, we used enzymatic digestions from the small intestine in a mouse. After that, the ICCs were identified immunologically by using the anti-c-kit antibody. In the ICCs, the electrophysiological whole-cell patch-clamp configuration was used to record pacemaker potentials in the cultured ICCs. Results: The ICCs generated pacemaker potentials in the mouse small intestine. SMS produced membrane depolarization with concentration-dependent manners in the current clamp mode. Pretreatment with a $Ca^{2+}$ free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in the endoplasmic reticulum, stopped the generation of the pacemaker potentials. In the case of $Ca^{2+}$-free solutions, SMS induced membrane depolarizations. However, when thapsigargin in a bath solution was applied, the membrane depolarization was not produced by SMS. The membrane depolarizations produced by SMS were inhibited by U-73122, an active phospholipase C (PLC) inhibitors. Furthermore, chelerythrine and calphostin C, a protein kinase C (PKC) inhibitors had no effects on SMS-induced membrane depolarizations. Conclusions: These results suggest that SMS might affect GI motility by modulating the pacemaker activity through an internal $Ca^{2+}$- and PLC-dependent and PKC-independent pathway in the ICCs.

• 대한한의학회지
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• 제23권2호
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• pp.164-179
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• 2002

Object: Death rate due to hypertension, atherosclerosis, ischemic heart disease and cerebral infarction induced by Westernized diet and increased average life span is on the rise. Decrease in blood circulation, activation of thrombus generation and intravascular lipid accumulation, cited as the principal causes of the above mentioned diseases in recent studies, result in circulatory disturbance and blood vessel obstruction leading to ischemic cell death of heart, brain and peripheral vessels. Method: We investigated the biochemical changes in microvascular permeability, aggregation of platelet and the intravascular lipid accumulation in induced-diabetic rat using Streptozotocin. We also studied the effects of Woohwangcheongsirn-won after oral administration on blood circulation, platelet function and lipid metabolism. The results are as follows: I. Woohwangcheongsim-won increased blood circulation in microvessels. 2. Woohwangcheongsim-won increased the reduced erythrocyte deformability in diabetes. 3. Woohwangcheongsim-won induced the reduction of contents of 2, 3-DPG, but failed to affect the reduced contents of ATP in erythrocyte in diabetes. 4. Woohwangcheongsim-won reduced the activity of Ca/sup 2+/-ATPase in the membrane of erythrocyte. 5. Woohwangcheongsim-won reduced the platelet aggregation evoked by platelet agglutinin factor. 6. Woohwangcheongsim-won reduced the production of platelet-derived granules. 7. Woohwangcheongsim-won reduced the production of metabolites of arachidonic acid in diabetes, and also reduced the production of increased thromboxane B2. 8. Woohwangcheongsim-won reduced the synthesis of oxidized LDL-cholesterol. In conclusion, Woohwangcheongsim-won enhanced blood circulation in microvesseles, erythrocyte deformability and inhibited the increased platelet aggregation and the synthesis of oxidized LDL-cholesterol in diabetes. Therefore Woohwangcheongsim-won is believed to positively affect blood circulation (J Korean Oriental Med 2002;23(2):164-179)

• 한국수산과학회지
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• 제31권6호
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• pp.823-828
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• 1998

명태 actomyosin 용액에 대한 옥수수전분 가수분해물의 동결 보호 효과는 전기영동상 패턴, 용해도 및 $Ca^{2+}$-ATPase 활성 변화로 알아보았다. 먼저 전기영동상 패턴에서 0일차와 저장 30일차를 비교하였을 때, control의 경우 저장온도에 관계없이 각 band들의 변화가 수반되었고, 특히 MHC의 변화가 두드러졌다. Sucrose 첨가구의 경우, 저장온도에 상관없이 band상의 변화가 거의 없는 것으로 나타났다. 전분가수분해물이 첨가된 시료들에서는 온도 의존성이 현저하여 $-5^{\circ}C$에서 저장한 시료들은 MHC band가 나타나지 않았고 반면에 $-20^{\circ}C$에서는 저장 30일 째에도 0일차와 거의 같은 양상을 보였다. 시료들을 $-5^{\circ}C$에서 저장할 때 용해도 변화는 sucrose의 경우 저장 30일 후에도 $90\%$ 이상의 높은 값을 유지한 반면에 나머지 시료들은 저장과 함께 급속히 감소하였다 $-20^{\circ}C$에서는 sucrose, D.E. 10, 15 및 20을 함유한 시료들은 약 $90\%$ 정도를 나타내었다. 잔존 활성 변화에서도 용해도 변화와 거의 유사한 경향을 나타내었다. 이상에서 살펴보았듯이 명태 actomyosin 용액의 동결변성에 대한 옥수수전분가수분해물들의 보호효과는 저장온도에 따라 많은 차이를 나타내었고, 특히 D.E. 10의 경우는 기존의 동결변성 방지제인 sucrose와 비교하여 $-12^{\circ}C$ 이하에서는 거의 같은 효과를 나타내는 것을 알았고, 저감미, 저열량의 동결변성 방지제로서 가능한 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제17권1호
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• pp.32-42
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• 2009

The purpose of the present study was to examine the effect of dihydrexidine, a full $D_1$ receptor agonist, on the secretion of catecholamines (CA) from the perfused model of the rat adrenal gland, and to establish its mechanism of action. Dihydrexidine (10-100 ${\mu}M$), perfused into an adrenal vein for 60 min, relatively produced dose- and time-dependent inhibition in the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM), DMPP (100 ${\mu}M$) and McN-A-343 (100 ${\mu}M$). Dihydrexidine itself did fail to affect basal CA output. Also, in adrenal glands loaded with dihydrexidine (30 ${\mu}M$), the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}M$), an activator of L-type $Ca^{2+}$ channels, cyclopiazonic acid (10 ${\mu}M$), an inhibitor of cytoplasmic $Ca^{2+}$-ATPase, and veratridine, an activator of voltage-dependent $Na+$ channels (10 ${\mu}M$), were also markedly inhibited, respectively. However, in the simultaneous presence of dihydrexidine (30 ${\mu}M$) and R (+)-SCH23390 (a selective antagonist of $D_1$ receptor, 3 ${\mu}M$), the CA secretory responses evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644, cyclopiazonic acid and veratridine were considerably recovered to the extent of the corresponding control secretion compared with the inhibitory responses by dihydrexidinetreatment alone. In conclusion, these experimental results suggest that dihydrexidine significantly inhibits the CA secretion evoked by cholinergic stimulation (both nicotinic and muscarinic receptors) and membrane depolarization from the rat adrenal medulla. It seems that this inhibitory effect of dihydrexidine may be mediated by inhibiting influx of both $Ca^{2+}$ and $Na^+$ into the cytoplasm as well as by suppression of $Ca^{2+}$ release from cytoplasmic calcium store through activation of dopaminergic $D_1$ receptors located on the rat adrenomedullary chromaffin cells.