Bathing in carbon dioxide-enriched water alters protein expression in keratinocytes of skin tissue in rats.

Beneficial effects of balneotherapy using naturally occurring carbonated water (CO2 enriched) have been known since the Middle Ages. Although this therapy is clinically applied for peripheral artery disease and skin disorder, the underlying mechanisms are not fully elucidated.Under controlled conditions, rats were bathed in either CO2-enriched water (CO2 content 1200 mg/L) or tap water, both at 37 °C, for 10 min daily over 4 weeks. Proliferation activity was assessed by Ki67 immunohistochemistry of the epidermis of the abdomen. The capillary density was assessed by immunodetection of isolectin-positive cells. Using cryo-fixed abdominal skin epidermis, follicle cells and stroma tissue containing capillaries were separately isolated by means of laser microdissection and subjected to proteomic analysis using label-free technique. Differentially expressed proteins were validated by immunohistochemistry.Proliferation activity of keratinocytes was not significantly different in the epidermis after bathing in CO2-enriched water, and also, capillary density did not change. Proteomic analysis revealed up to 36 significantly regulated proteins in the analyzed tissue. Based on the best expression profiles, ten proteins were selected for immunohistochemical validation. Only one protein, far upstream element binding protein 2 (FUBP2), was similarly downregulated in the epidermis after bathing in CO2-enriched water with both techniques. Low FUBP2 expression was associated with low c-Myc immune-expression in keratinocytes.Long-term bathing in CO2-enriched water showed a cellular protein response of epithelial cells in the epidermis which was detectable by two different methods. However, differences in proliferation activity or capillary density were not detected in the normal skin.

Mechanism of sarpogrelate action in improving cardiac function in diabetes.

Although sarpogrelate, a 5-HT(2A) receptor antagonist, has been reported to exert beneficial effects in diabetes, the mechanisms of its action are not understood. In this study, diabetes was induced in rats by an injection of streptozotocin (65 mg/kg) and the animals were assessed 7 weeks later. Decreased serum insulin as well as increased serum glucose, cholesterol, and triglyceride levels in diabetic animals were associated with increased blood pressure and heart/body weight ratio. Impaired cardiac performance in diabetic animals was evident by decreased heart rate, left ventricular developed pressure, rate of pressure development, and rate of pressure decay. Treatment of diabetic animals with sarpogrelate (5 mg/kg) or insulin (10 units/kg) daily for 6 weeks attenuated the observed changes in serum insulin, glucose, and lipid levels as well as blood pressure and cardiac function by varying degrees. Protein content for membrane glucose transporters (GLUT-1 and GLUT-4) was depressed in diabetic heart; the observed alteration in GLUT-4 was partially prevented by both sarpogrelate and insulin, whereas that in GLUT-1 was attenuated by sarpogrelate only. Incubation of myoblast cells with sarpogrelate and insulin stimulated glucose uptake; these effects were additive. 5-hydroxytryptamine was found to inhibit glucose-induced insulin release from the pancreas; this effect was prevented by sarpogrelate. These results suggest that sarpogrelate may improve cardiac function in chronic diabetes by promoting the expression of membrane glucose transporters as well as by releasing insulin from the pancreas.

Antiplatelet agents sarpogrelate and cilostazol affect experimentally-induced ventricular arrhythmias and mortality.

Antiplatelet agents, sarpogrelate (SAR), a 5-hydroxy tryptamine 2A receptor antagonist and cilostazol (CIL), a phosphodiesterase-III inhibitor, were observed to be beneficial in attenuating cardiac remodeling and improving cardiac function in congestive heart failure due to myocardial infarction in rats; however, CIL increased ventricular tachycardia and mortality. In order to study the effects of these antiplatelet agents on arrhythmias, Sprague-Dawley rats were pretreated with either SAR or CIL (5 mg/kg/day) for 2 weeks and were then either injected cumulative doses of epinephrine (Epi) or subjected to coronary occlusion. Saline-treated animals served as controls. Electrocardiographic analysis revealed that SAR pretreatment decreased the incidence and severity of ventricular arrhythmias (time of onset of arrhythmias as well as the occurrence of premature ventricular contractions, salvos, tachycardia, and fibrillations), whereas CIL treatment augmented the incidence of cardiac arrhythmias due to both Epi and coronary occlusion. None of the drugs affected the corrected QT interval significantly. Furthermore, the levels of cyclic adenosine monophosphate (cAMP) in left ventricle were markedly higher in CIL-pretreated rats when compared to SAR-pretreated or control rats. It is suggested that an excessive level of cAMP may contribute to increase incidence of ventricular arrhythmias and mortality in animals pretreated with CIL, unlike the SAR-pretreated rats.

Antiplatelet therapy mitigates cardiac remodeling and dysfunction in congestive heart failure due to myocardial infarction.

Antiplatelet agents such as sarpogrelate (SAR), a 5-hydroxytryptamine antagonist, and cilostazol (CIL), a phosphodiesterase-III inhibitor, are used in the management of peripheral vascular disease. In this study, we tested the hypothesis that both SAR and CIL prevent cardiac remodeling and improve cardiac function in congestive heart failure (CHF) due to myocardial infarction (MI). Post-MI rats (3 weeks after the occlusion of coronary artery) received either vehicle (MI+V, n = 36), SAR (MI+SAR; 5 mg xc kg(-1) x day(-1), n = 35) or CIL (MI+CIL; 5 mg x kg(-1) x day(-1), n = 34) from day 21 to day 56. Sham-operated rats (n = 29) served as controls. Electrocardiographic, echocardiographic, and hemodynamic parameters were measured on day 56. Treatment of infarcted animals with SAR or CIL significantly improved the left ventricular (LV) dimensions, LV fractional shortening, cardiac output, stroke volume, mean arterial pressure, LV diastolic function, and LV systolic pressure, as well as rates of LV pressure development and pressure decay. Although cardiac hypertrophy was reduced, both SAR and CIL had no effect on infarct size or MI-associated QTc prolongation. However, SAR decreased whereas CIL increased the incidence of ventricular arrhythmias and the mean number of episodes in infarcted animals. Mortality during the treatment period was decreased by 17% with SAR and increased by 10% with CIL, but these changes were not significant statistically. The data in this study suggest that both SAR and CIL prevent cardiac remodeling and improve cardiac function in MI-induced CHF; however, CIL unlike SAR increased the incidence of arrhythmias and adversely affected patient mortality.

Antiplatelet therapy attenuates subcellular remodelling in congestive heart failure.

Antiplatelet agents, sarpogrelate (SAR), a 5-HT(2A) receptor antagonist, and cilostazol (CIL), a phosphodiesterase III (PDE-III) inhibitor, are used for the treatment of peripheral vascular disease. We tested whether these agents affect cardiac function and subcellular remodelling in congestive heart failure (CHF) induced by myocardial infarction (MI). Three weeks after MI, rats were treated daily with 5 mg/kg SAR or CIL as well as vehicle for 5 weeks. Sham-operated animals served as controls. At end of the treatment period, haemodynamic measurements were performed and the left ventricle was processed for the determination of sarcoplasmic reticulum (SR) Ca(2+)-uptake and -release activities, and expression of SR Ca(2+)-pump, phospholamban and ryanodine receptors, as well as myofibrillar ATPase activities, expression of alpha- and beta-myosin heavy chain (MHC) isoforms, and phosphorylation of phospholamban and cardiac troponin-I (c Tn-I). Marked haemodynamic changes in the MI-induced CHF were associated with depressions in SR Ca (+)-uptake and -release activities as well as in protein content and gene expression for SR proteins. Furthermore, myofibrillar Ca(2+)-stimulated ATPase activity, as well as protein content and gene expression for alpha-MHC were decreased whereas those for beta-MHC were increased in the failing heart. Also, phosphorylation levels of phospholamban and cTn-I were reduced in failing hearts. The MI-associated changes in cardiac function, SR and myofibillar activities, as well as SR and myofibrillar protein and gene expression were attenuated by treatment with SAR or CIL. The results suggest that SAR and CIL improve cardiac function by ameliorating subcellular remodelling in the failing heart and indicate the potential therapy of CHF with antiplatelet agents.

Therapeutic potentials of sarpogrelate in cardiovascular disease.

In view of the pivotal role of serotonin (5-HT) in a wide variety of cardiovascular disorders, extensive effort has been made to develop different types of 5-HT receptor antagonists for therapeutic use. On the basis of experimental studies, this article is focused on the potentials of sarpogrelate, a specific 5-HT2A receptor antagonist as an antiplatelet, antithrombotic, antiatherosclerotic and antianginal agent. The major effects of sarpogrelate are due to the inhibition of 5-HT-induced platelet aggregation and smooth muscle cell proliferation. This agent was found to attenuate the 5-HT-mediated increase in intracellular Ca2+ and ischemia-reperfusion injury in the heart. Sarpogrelate has been found to have beneficial effects in peripheral vascular disease, restenosis after coronary stenting, pulmonary hypertension, acute and chronic myocardial infarction.

Attenuation of the serotonin-induced increase in intracellular calcium in rat aortic smooth muscle cells by sarpogrelate.

Although serotonin (5-HT) induced proliferation of vascular smooth muscle cells is considered to involve changes in intracellular Ca2+ ([Ca2+]i), the mechanism of Ca2+ mobilization by 5-HT is not well defined. In this study, we examined the effect of 5-HT on rat aortic smooth muscle cells (RASMCs) by Fura-2 microfluorometry for [Ca2+]i measurements. 5-HT was observed to increase the [Ca2+]i in a concentration- and time-dependent manner. This action of 5-HT was dependent upon the extracellular concentration of Ca2+ ([Ca2+]e) and was inhibited by both Ca2+ channel antagonists (verapamil and diltiazem) and inhibitors of sarcoplasmic reticular Ca2+ pumps (thapsigargin and cyclopia zonic acid). The 5-HT-induced increase in [Ca2+]i was blocked by sarpogrelate, a 5-HT2A-receptor antagonist, but not by different agents known to block other receptor sites. 5-HT-receptor antagonists such as ketanserin, cinanserin, and mianserin, unlike methysergide, were also found to inhibit the 5-HT-induced Ca2+ mobilization, but these agents were less effective in comparison to sarpogrelate. On the other hand, the increase in [Ca2+]i in RASMCs by ATP, angiotensin II, endothelin-1, or phorbol ester was not affected by sarpogrelate. These results indicate that Ca2+ mobilization in RASMCs by 5-HT is mediated through the activation of 5-HT2A receptors and support the view that the 5-HT-induced increase in [Ca2+]i involves both the extracellular and intracellular sources of Ca2+.

Blockade of 5-HT(2A) receptors by sarpogrelate protects the heart against myocardial infarction in rats.

BACKGROUND: It has been shown that serotonin (5-hydroxytryptamine, 5-HT) is involved in exacerbating vascular abnormalities; however, its role in mediating changes in cardiac function due to myocardial injury has yet to be established. This study examined the effect of sarpogrelate, a 5-HT(2A) receptor blocker, in preventing cardiac dysfunction due to myocardial infarction (MI). METHODS AND RESULTS: Rats were treated 3 days before surgery with or without 5 mg x kg(-1) x day(-1) sarpogrelate, and the left coronary artery was ligated for 3 weeks to induce MI. Sarpogrelate reduced the mortality from 40% to 30%, infarct size from 35% to 25%, and left ventricular end diastolic pressure from 15 mm Hg to 10 mm Hg in MI rats. Electrocardiographic (ECG) tracings showed a marked deviation in the ST-segment and prolongation of the QTc interval in MI rats during the 3 weeks; these changes were attenuated by sarpogrelate pretreatment. In another set of experiments, MI rats were treated with 5 mg x kg(-1) x day(-1) sarpogrelate 1 hour after the surgery, and the hemodynamic and electrocardiograph changes were assessed at 3 weeks. This posttreatment was also found to reduce infarct size, improve cardiac function, and attenuate ECG changes. CONCLUSIONS: Sarpogrelate attenuates cardiac dysfunction, infarct size, and changes in the ECG due to MI. These results also support the view that serotonin and 5-HT(2A) may contribute to the deleterious effects of ischemic injury in the heart.