• 한국패류학회지
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• 제25권1호
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• pp.15-22
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• 2009

Because it is known that bivalve hearts contain various modulatory systems activated by neuroendocrine substances, it was examined whether different classes of endogenous and synthetic drugs of neuroendocrinological importance can influence cardiac functions of the Pacific oyster Crassostrea gigas. Cholinergically active agents acetylcholine and carbachol increased heart rates while diminishing cardiac contractility. Adrenergically active substances norepinephrine (NE) and epinephrine (Epi) also induced heart rate increase and contractility decrease. An $\alpha_1$-adrenergic receptor-selective agonist phenyephrine (PE) failed to modulate either parameter. The Epi-induced heart rate increase and contractile depression were both blocked significantly by non-selective $\beta_1/\beta_2$-adrenergic antagonist propranolol. A $\beta_1$-selective antagonist atenolol prevented Epi-induced heart rate decrease but not the contractile depression, suggesting possible $\beta_2$ receptors for Epi-induced contractile depression. The three autacoids examined exerted discrete responses: histamine increased heart rate and depressed contraction; $\gamma$-amino-butyric acid increased both parameters; serotonin failed to change either parameter. The 5 piscine anesthetic agents examined, MS-222, benzocaine, quinaldine, urethane, pantocaine and pentobarbital, all failed to influence the cardiac function of oysters. Collectively, activities of neuroendocrinologically acting agents in mammals showed unexpected and distinct activities from those in mammalian cardiovascular systems. These results obtained from substances of different physiological functions can serve as a basis for understanding neuroendocrine control of the heart function in Pacific oyster.

• 대한한방소아과학회지
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• 제19권1호
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• pp.11-23
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• 2005

Objectives : In the present study, the authors intended to investigate whether two oriental medical prescriptions named chwiyeon-tang and chihyosan-gamibang significantly affect much release from cultured hamster tracheal surface epithelial HTSE cells. Methods : Confluent HTSE cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of chwiyeon-tang or chihyosan-gamibang to assess the effect of each agent on 3H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase LDH release. Also, the effect of chwiyeon-tang and chihyosan-gamibang on contractility of isolated tracheal smooth muscle were investigated. Results : (1) Chwiyeon-tang significantly inhibited mucin release from cultured HTSE cells, with significant cytotoxicity ; (2) Chihyosan-gamibang significantly stimulated mucin release from cultured HTSE cells, with minute cytotoxicity ; (3) Chwiyeon-tang and Chihyosan-gamibang did not affect contractility of isolated tracheal smooth muscle. Conclusions : We suggest that the effects of Chwiyeon-tang and Chihyosan-gamibang with their components should be further investigated and it is of great value to find, from oriental medical prescriptions, noel agents which might regulate mucin secretion from airway goblet cells.

• Journal of Chest Surgery
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• 제21권2호
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• pp.223-230
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• 1988

Emax, end-systolic pressure-volume relationship, has been established as a new concept which can be representative of ventricular contractility itself since 1970s. Comparing to ejection fraction[EF], Emax is independent of preload and afterload. However Emax has not been proved precisely in non-thoracotomized condition because current methods have limitation in measuring ventricular chamber volume accurately in in viva state. The Dynamic Spatial Reconstructor[DSR], high speed computerized tomography, can measure ventricular chamber volume accurately throughout cardiac cycle in non-thoracotomized state. So Emax and EF of the left ventricle was tried to measure precisely in in vivo condition with DSR. Emax was compared to EF to estimate its ability to evaluate ventricular contractility. 5 mongrel dogs, weighing 15-16kg, were used for measuring Emax and EF of the left ventricle in 3 or 4 different loading conditions using DSR. Emax value in 5 dogs was from 2.62 to 10.49. Each dog has one Emax value regardless of loading conditions. However EF in 5 dogs varies depending on loading conditions. The conclusions are that Emax is useful in in viva state and EF varies depending on loading conditions. So Emax should be tried to use in clinical situation rather than EF because it is always representative of contractility itself regardless loading conditions in in viva state.

• 약학회지
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• 제37권2호
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• pp.163-171
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• 1993

In order to study the functions of vascular endothelial nitric oxide(NO) generating system, we examined the effects of monomethylarginine(MMA) and dimethylarginine(DMA)(asym., sym.), arginine analogues, on modulation of vascular tone. Also, the concentrations of endogenous arginie and MMA were measured by HPLC in rat aortic tissues. The results were as follows. 1. The maximum relaxation induced by Ach (1.5$\times$10$^{-6}$M) was 80% of the contractility of rings of rat aorta induced by phenylephrine and L-Arg causes endothelium-dependent relaxation of the aorta precontracted with phenylephrine and these relaxation were concentration-dependent. 2. Endothelium-dependent contractility of rings of rat aorta induced by MMA (100 $\mu{M}$), DMA (asym., 100 $\mu{M}$) and DMA (sym., 100 $\mu{M}$) were 25.5%, 27.5% and 16.5% of that induced by phenylephrine respectively. 3. The relaxation of rat aortic ring induced by L-Arg was inhibited by MMA, DMA(asym.) and DMA(sym.). The degrees of inhibition induced by MMA, DMA(asym.) and DMA(sym.) were 45.7%, 37.1% and 18.3%, respectively. 4. The endogenous arginine and monomethylarginine contents in rat aorta were 83 pmoles/mg wet tissue, and 34.9 pmoles/mg wet tissue. After stimulation with Ach, the concentrations of L-Arg and MMA were significantly decreased. These results suggest that there are the strong relationships between the endogenous L-Arg and methylated arginines and NO-generating system.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2003년도 학술대회
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• pp.86-91
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• 2003

In this study, in order to examine whether salt and heat shock stress would alter or not contraction and relaxation of isolated rat aorta. Under anesthesia with sodium pentobarbital(50 mg Kg$^{-1}$ i.p.), male Sprague Dawley rats weighing 300-330 g were subjected to 0, heat shock combined salt stress, where as the sham group was left at modified Krebs-bicarbonate solution. To measure contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And the strip was checked for expression of heat shock protein(Hsps) by means of western blotting. The combination group of heat and 50 mM NaCl group increased vascular contractility, and the heat and 150 mM NaCl group decreased vascular contractility for 5 hours, and then recovered for 8 hours compared to that of control. Expressin of Hsp 70 of vascular muscle of rat aorta more increased by combination of heat and NaCl treatment than those of single treatment of heat or NaCl treatment, and vascular Hsp 70 showed a little decrease at 8 hours compared at 5 hours. These result indicate that mixed environmental stress either increased or decreased in vascular contractility by combination of heat and NaCl concentration.

• The Korean Journal of Physiology and Pharmacology
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• 제5권1호
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• pp.47-53
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• 2001

Drinking excessive alcohol has been recognized as a risk factor for hypertension. However, the mechanism by which alcohol intake causes hypertension still remains elusive. We tested the hypothesis that ethanol itself acts as a stress factor on vasculature and indirectly modulates vascular contractility. After end of exposure to 1, 2.5 and 5% ethanol for 45 min, rat aortic strips were subjected to contractile responses, immunoblot for Hsp70 and the measurement of levels of myosin light chain phosphorylation. Exposure to 5% ethanol not only augmented contractions to KCl or phenylephrine, but also increased expression of Hsp70 and the levels of myosin light chain phosphorylation. There were no significant differences in contractions produced by $1\;{\mu}mol/L$ phorbol 12,13-dibutyrate, a protein kinase C activator, whether the tissues were exposed to 5% ethanol or not. This is the first report to show that even short exposure to ethanol has a delayed effect to increase vascular smooth muscle contractility through a modulation of thick filament regulation. It may be a mechanism by which ingestion of alcohol induces hypertension.

• 대한물리의학회지
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• 제14권3호
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• pp.47-53
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• 2019

PURPOSE: This study measured the external pressure on abdomen during maximal inspiration. The study determined the correlation between the diaphragmatic contraction pressure and the lung capacities to verify whether or not the measured pressure values can represent diaphragmatic contractility. METHODS: The study included 32 healthy subjects (16 males and 16 females). The researchers fabricated their own diaphragmatic pressure belt (DiP Belt) to measure DCP. DiP Belt device was fixed on the front of the abdomen and the diaphragmatic contractility was measured during maximal inspiration. The lung capacities were measured using a portable digital spirometer device (Pony Fx, COSMED, Italy). A digital spirometer is a device that is used to test the flow of air entering and exiting the lungs. RESULTS: DCP showed significant positive correlations with vital capacity (VC), inspiratory reserve volume (IRV) and inspiratory capacity (IC). Among values of lung capacities, IC showed especially strong positive correlations with the DCP (r =.714, p<.010). For the males, DCP showed significant positive correlations with IRV and IC, and DCP showed significant negative correlation with the expiratory reserve volume (ERV). For the females, DCP showed significant positive correlation with tidal volume (VT), but any significant correlation was not found with any of the other values of lung capacities. CONCLUSION: DCP showed high correlations with IRV and IC associated with inspiratory capacity. Therefore, The DiP Belt can be looked upon as a simple device that is very useful for measuring diaphragmatic contractility.

• 환경생물
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• 제21권3호
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• pp.313-318
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• 2003

외부에서 투여된 열자극, 알콜 및 생리적 염과 같은 환경 스트레스는 체내 각 부위에서 스트레스단백질(열자극단백질, HSP)을 생성하게 된다. 본 연구에서는 비소가 흰쥐 대동맥의 수축에 미치는 영향을 조사하기 위해 스트레스단백질의 발현과 대동맥의 수축력의 변화와 이들과의 관계를 알아보고자 실험을 실시하였다 적출한 혈관은 organ bath에 담가 0, 0.5, 1, 2,및 4 mM As를 처리한 후 1, 3, 및 8시간 뒤에 KCI(55 mM)에 대한 수축반응과 HSP 발현을 각각 생리기록계와 western blotting 을 통해 분석하였다. 비소(4 mM)를 처리한 혈관의 KCI에 대한 수축력은 처리 초기(1, 3시간)에는 효과가 없었고 처리 8시간째 대조군에 비해 39％로 유의적인 증가를 보였다. 또한 비소처리로 혈관의 스트레스단백질 HSP 70의 생성은 비소 처리농도에 따라 증가되었고, 비소 처리 초기에는 변화가 없었으며 비소처리 8시간째 HSP생성이 촉진되었다. HSP는 주로 혈관 평활근세포에서 현저하게 발현되었고 일부 내피세포에서도 발현되었다. 이상의 결과에서 비소 처리에 따른 HSP 70의 발현과 혈관의 수축 증가의 상승되는 현상이 비소처리 8시간째에 유의하게 증가되는 것으로 보아, 비소처리에 의해 혈관의 스트레스단백질 HSP 발현이 증가되고 이로 인해 혈관 수축력을 상승시켜 고혈압 유발과정에 관여하는 것으로 여겨진다.

• The Korean Journal of Physiology
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• 제21권1호
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• pp.35-46
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• 1987

It has been well known that estrogens stimulate the uterine contractility and progestins inhibit it. Then, one may expect that the uterine contractility and sensitivities to oxytocin (OT) and prostaglandin $F_{2{\alpha}}\;(PGF_{2{\alpha}})$ would be different among the estrus cycle. These hypotheses were tested using the mature female rat. Spontaneous isometric contractions of isolated uterine strips $(1{\times}0.3\;cm)$ from cyclic rats in various stages of the estrus cycle, bilateral ovarectomized rats and hypophysectomized rats were recorded in absence or presence with $estradiol-17{\beta}\;(E_2)$, progesterone $(P_4)$, OT and $PGF_{2{\alpha}}$. The results were summarized as follows: 1) The spontaneous uterine contractile force was the highest in the estrus rat and the lowest in the ovarectomized or the hypophysectomized rat. In the proestrus rat, the contractile frequency was the lowest (2.7 beats/10 min) and the contractile duration was the longest (70 sec). In the other groups, there were no any differencies in frequency (9 beats/10 min) and in duration (30 sec). 2) OT and $PGF_{2{\alpha}}$ stimulated the uterine contractility in all groups tested except in the hypophysectomized rat in which OT failed to stimulate the uterine contraction. $PGF_{2{\alpha}}$ was more effective in stimulating the uterine contraction than OT in all groups tested except in the estrus rat. OT-induced contraction was the highest in the estrus rat and $PGF_{2{\alpha}}-induced$ contraction was the lowest in the hypophysectomized rat. 3) Uterine contractilities were not changed by the in vitro treatments of $E_2$ or $P_4$ under the influence of endogenous steroids, however, $E_2$ and $P_4$ stimulated the uterine contraction in the ovarectomized rat in which endogenous steroids were almost abolished. 4) Increased uterine contraction by the treatment of OT was suppressed by in vitro $E_2$ or $P_4$ in the estrus rat, while it was potentiated by the $P_4$ in the proestrus rat. In other groups, exogenous $E_2$ or $P_4$ did not affect the OT-induced uterine contraction. 5) $PGF_{2{\alpha}}-induced$ uterine contraction was suppressed in the ovarectomized rat by $E_2$ and $P_4$, in the diestrus and proestrus rats by $P_4$ and in the hypophysectomized rat by $E_2$. In other groups, exogenous $E_2$ or $P_4$ was ineffective in altering the $PGF_{2{\alpha}}-induced$ uterine contraction. According to the above results, it may conclude that the mechanisms of the different uterine contractility and the different uterine sensitivity to OT or $PGF_{2{\alpha}}$ according to the estrus cycle are not explicable with only the serum concentrations of steroids, OT and $PGF_{2{\alpha}}$ but also other unknown factors.

• Journal of Chest Surgery
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• 제51권4호
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• pp.266-272
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• 2018

Background: Limited comparative data are available on the efficacy of cryoablation versus radiofrequency ablation in patients with atrial fibrillation. This study aimed to compare radiofrequency ablation and cryoablation with regard to clinical outcomes and the restoration of sinus rhythm or atrial contractility. Methods: A total of 239 patients who underwent surgical ablation between August 2003 and December 2016 at our institution were included. The patients were divided into 2 groups according to the energy device that was used (group A: n=140, radiofrequency ablator; group B: n=99, cryoablator). Echocardiographic data, overall survival, and major cardiovascular and cerebrovascular event (MACCE)-free survival were compared between the 2 groups. Results: At 1 year of follow-up, the atrial contractility recovery rate was 32.2% (19 of 59) in group A and 48.8% (21 of 44) in group B. In addition, cryoablation was found to be a predictive factor for the recovery of atrial contractility (cryoablation vs. radiofrequency ablation: odds ratio, 2.540; 95% confidence interval, 1.063-6.071; p=0.036). The left ventricular ejection fraction was significantly higher in group B ($53.1%{\pm}11.5%$ vs. $59.1%{\pm}6.3%$, p=0.001). The median follow-up duration was 36 months. The 5-year overall survival rate was $80.1%{\pm}3.6%$ in group A and $92.1%{\pm}2.9%$ in group B (p=0.400). The 5-year MACCE-free survival rate was $70.3%{\pm}4.0%$ in group A and $70.9%{\pm}5.6%$ in group B (p=0.818). Conclusion: Cryoablation was associated with a higher atrial contractility restoration rate and better left ventricular function than radiofrequency ablation. However, no significant relationship was observed between the energy source and overall or MACCE-free survival.