Possible therapeutics for Pseudomyxoma peritonei: a rare, lethal, and the least investigated disease

Pseudomyxoma peritonei (PMP) refers to a growth disorder characterized by glycoprotein neoplasm in the peritoneum, where mucin oversecretion occurs. The tumors of the appendix region are well associated with PMP; however, ovarian, colon, stomach, pancreas, and urachus tumors have also been linked to PMP. Other mucinous tumors in the pelvis, paracolic gutters, greater omentum, retrohepatic space, and Treitz ligament can be the reason for PMP. Despite being rare and having a slow growth rate, PMP can be lethal without treatment. It is treated with neoadjuvant chemotherapy with the option of cytoreductive surgery and intraperitoneal chemotherapy. In the current study, we hypothesize that there may be novel gentle ways to inhibit or eliminate the mucin. Dr. David Morris has used mucolytics - such as bromelain and N-acetyl cysteine to solubilize mucin. In the present review, we aimed to study the regulation of mucin expression by promoter methylation, and drugs that can inhibit mucin, such as boldine, amiloride, naltrexone, dexamethasone, and retinoid acid receptors antagonist. This review also explored some possible pathways, such as inhibition of Na + , Ca2+ channels and induction of DNA methyltransferase along with inhibition of ten-eleven translocation enzymes, which can be good targets to control mucin. Mucins are strong adhesive molecules that play great roles in clinging to cells or cell to cell. Besides, they have been greatly involved in metastasis and also act as disease markers for cancers. Diagnostic markers may have exclusive roles in disease initiation and progression. Therefore, the present review explores various drugs to control and target mucin in various diseases, specifically cancers. (AU)

Hipertensão resistente: análise dos estudos pathway 2 e 3 / Resistant hypertension: analysis of pathway 2 and 3 studies

A hipertensão arterial resistente (HAR) é definida quando, apesar do tratamento com pelo menos três medicações anti- -hipertensivas (incluindo um diurético) de diferentes classes a meta pressórica não é alcançada. Nesta sequência de fármacos, por muitos anos se utilizou empiricamente ou baseado em pequenos estudos, a espironolactona. Os estudos Pathway 2 e 3 vieram para corroborar a importância deste quarto fármaco, a espironolactona, como o mais eficaz em termos de potencia anti-hipertensiva, como também explicar os aspectos fisiopatológicos que levam o hipertenso a ficar resistente. Nesta revisão e análise crítica dos fármacos anti-hipertensivos na HAR destacamos os principais mecanismos envolvidos no não controle da pressão e as estratégias para um melhor controle pressórico

Resistant arterial hypertension (RAH) is defined when, despite treatment with at least three antihypertensive medications (including a diuretic) of different classes, the pressure target is not achieved. In this sequence of drugs, for many years it was used empirically or based on small studies, spironolactone. Pathway 2 and 3 studies have come to corroborate the importance of this fourth drug, spironolactone, as the most effective in terms of antihypertensive potency, as well explain the pathophysiological aspects that lead hypertensive patients to become resistant. In this review and critical analysis of antihypertensive drugs in hypertension, we highlight the main mechanisms involved in the lack of pressure control and the strategies for better pressure control

Diuretics are Similar to Losartan on Echocardiographic Target-Organ Damage in Stage I Hypertension. PREVER-Treatment Study / Diuréticos são Similares à Losartana na Avaliação Ecocardiográfica de Lesão a Órgãos-Alvo no Estágio I da Hipertensão. Estudo PREVER-Treatment

Abstract Blood pressure (BP)-lowering therapy improves left ventricular (LV) parameters of hypertensive target-organ damage in stage II hypertension, but whether there is a drug-class difference in echocardiographic parameters in stage I hypertension patients is less often studied. In the PREVER treatment study, where individuals with stage I hypertension were randomized for treatment with diuretics (chlorthalidone/amiloride) or losartan, 110 participants accepted to participate in a sub-study, where two-dimensional echocardiograms were performed at baseline and after 18 months of antihypertensive treatment. As in the general study, systolic BP reduction was similar with diuretics or with losartan. Echocardiographic parameters showed small but significant changes in both treatment groups, with a favorable LV remodeling with antihypertensive treatment for 18 months when target blood pressure was achieved either with chlorthalidone/amiloride or with losartan as the initial treatment strategy. In conclusion, even in stage I hypertension, blood pressure reduction is associated with improvement in echocardiographic parameters, either with diuretics or losartan as first-drug regimens.

Resumo A terapia de redução da pressão arterial (PA) melhora os parâmetros do ventrículo esquerdo (VE) na lesão a órgãos-alvo causada pela condição hipertensiva na hipertensão de estágio II; no entanto, se existem ou não diferenças relacionadas à classe de medicamentos nos parâmetros ecocardiográficos de pacientes com hipertensão estágio I é menos frequentemente estudado. No estudo PREVER-treatment, em que indivíduos com hipertensão estágio I foram randomizados para tratamento com diuréticos (clortalidona/amilorida) ou losartana, 110 participantes aceitaram participar de um subestudo, no qual foram realizados ecocardiogramas bidimensionais basais e após 18 meses de tratamento anti-hipertensivo. Como no estudo geral, a redução da PA sistólica foi semelhante com diuréticos ou com losartana. Os parâmetros ecocardiográficos mostraram pequenas mas significativas alterações em ambos os grupos de tratamento, com um remodelamento favorável do VE com tratamento anti-hipertensivo por 18 meses, quando a pressão arterial alvo foi atingida com clortalidona/amilorida ou com losartana como estratégia inicial de tratamento. Em conclusão, mesmo na hipertensão estágio I, a redução da pressão arterial está associada à melhora nos parâmetros ecocardiográficos tanto com o uso de diuréticos ou losartana como primeiro esquema de tratamento farmacológico.

The electrophysiological response of chorda tympani nerve to taste stimuli in rats with conditioned taste aversion to saltiness / 中国应用生理学杂志

OBJECTIVE@#To explore the characteristic changes of the peripheral chorda tympanic nerve (CT) electrophysiological responses to salty stimulus and other taste stimuli in rats with the conditioned taste aversion to saltiness.@*METHODS@#Fourteen adult SD male rats were divided into a conditioned taste aversion to salty group (CTA) and a control group (Ctrl) (n=7/group). On the first day of the experiment, rats were given a 0.1 mol/L NaCl intake for 30 min, then, the rats in CTA and Ctrl groups were injected intraperitoneally with 2 ml of 0.15 mol/L LiCl and the same amount of saline respectively. On day 2, 3 and 4, the 30 min consumption of NaCl and distilled water was measured for both groups of rats. On the 4th day after the behavioral test of that day, CT electrophysiological recording experiments were performed on CTA rats and control rats.@*RESULTS@#Compared with the rats in Ctrl group, the electrophysiological characteristics of CT in CTA group rats did not change significantly the responses to the series of NaCl and other four basic taste stimuli (P＞0.05). The amiloride, the epithelial sodium channel blocker, strongly inhibited the response of CT to NaCl in CTA and Ctrl group rats (P＜0.01).@*CONCLUSION@#The electrophysiological responses of CT to various gustatory stimuli do not significantly change in rats after the establishment of conditional taste aversion to the saltiness.

Gintonin facilitates catecholamine secretion from the perfused adrenal medulla

The present study was designed to investigate the characteristics of gintonin, one of components isolated from Korean Ginseng on secretion of catecholamines (CA) from the isolated perfused model of rat adrenal gland and to clarify its mechanism of action. Gintonin (1 to 30 µg/ml), perfused into an adrenal vein, markedly increased the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. The gintonin-evoked CA secretion was greatly inhibited in the presence of chlorisondamine (1 µM, an autonomic ganglionic bloker), pirenzepine (2 µM, a muscarinic M₁ receptor antagonist), Ki14625 (10 µM, an LPA₁/₃ receptor antagonist), amiloride (1 mM, an inhibitor of Na⁺/Ca²⁺ exchanger), a nicardipine (1 µM, a voltage-dependent Ca²⁺ channel blocker), TMB-8 (1 µM, an intracellular Ca²⁺ antagonist), and perfusion of Ca²⁺-free Krebs solution with 5mM EGTA (a Ca²⁺chelater), while was not affected by sodium nitroprusside (100 µM, a nitrosovasodialtor). Interestingly, LPA (0.3~3 µM, an LPA receptor agonist) also dose-dependently enhanced the CA secretion from the adrenal medulla, but this facilitatory effect of LPA was greatly inhibited in the presence of Ki 14625 (10 µM). Moreover, acetylcholine (AC)-evoked CA secretion was greatly potentiated during the perfusion of gintonin (3 µg/ml). Taken together, these results demonstrate the first evidence that gintonin increases the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. This facilitatory effect of gintonin seems to be associated with activation of LPA- and cholinergic-receptors, which are relevant to the cytoplasmic Ca²⁺ increase by stimulation of the Ca²⁺ influx as well as by the inhibition of Ca²⁺ uptake into the cytoplasmic Ca²⁺ stores, without the increased nitric oxide (NO). Based on these results, it is thought that gintonin, one of ginseng components, can elevate the CA secretion from adrenal medulla by regulating the Ca²⁺ mobilization for exocytosis, suggesting facilitation of cardiovascular system. Also, these findings show that gintonin might be at least one of ginseng-induced hypertensive components.

The effect of Cratylia floribunda lectin on renal hemodynamics and ion transport

Lectins have been described as glycoproteins that reversibly and specifically bind to carbohydrates. Legume lectins isolated from the subtribe Diocleinae (Canavalia, Dioclea andCratylia) are structurally homologous with respect to their primary structures. The Diocleinae lectins of Canavalia brasiliensis, Dioclea guianensis andCanavalia ensiformis have been shown to distinctly alter physiological parameters in isolated rat kidneys. Thus, the aim of this study was to investigate the effect of Cratylia floribunda lectin (CFL) on renal hemodynamics and ion transport in rats. In isolated perfused kidneys, CFL (10 mg/mL, n=5) increased RPP, RVR and decreased %TK+, but did not change urinary flow, glomerular filtration rate, sodium or chloride tubular transport. In isolated perfused mesenteric bed, CFL (3 and 10 mg/mL/min; n=4) did not alter tissue basal tonus or tissue contraction by phenylephrine (1 mM/mL/min). In conclusion, the seed lectin of Cratylia floribunda increased renal hemodynamic parameters showing a kaliuretic effect. This effect could be of tubular origin, rather than a result from haemodynamic alterations.

As lectinas são descritas como (glico)proteínas que se ligam, especificamente e reversivelmente, a carboidratos. Lectinas de leguminosas isoladas da subtribo Diocleinae (Canavalia, Dioclea eCratylia) são estruturalmente homólogas em relação às suas estruturas primárias. Demonstrou-se que as lectinas de DiocleinaeCanavalia brasiliensis, Dioclea guianensis eCanavalia ensiformis alteram diferentemente parâmetros fisiológicos em rins isolados de ratos. Dessa maneira, o objetivo deste estudo foi investigar o papel da lectina de Cratylia floribunda (CFL) na hemodinâmica renal e no transporte de íons em ratos. Em rins isolados perfundidos, CFL (10 mg/mL, n=5) aumentou a pressão de perfusão renal, a resistência vascular renal e reduziu o percentual do transporte tubular de K+, mas não alterou o fluxo urinário, a taxa de filtração glomerular e o percentual de transporte tubular dos íons sódio e cloreto. No leito mesentérico isolado perfundido, CFL (3 e 10 mg/mL/min, n=4) não alterou o tônus basal ou a contração do tecido induzida por fenilefrina (1 mM/mL/min). Em conclusão, a lectina de sementes de Cratylia floribunda altera parâmetros hemodinâmicos renais, provavelmente de origem tubular, e não por alterações hemodinâmicas.

Amiloride reduces proteinuria and inhibits podocyte uPAR in the 5/6 nephrectomy rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of amiloride on the proteinuria of the 5/6 nephrectomy rats.</p><p><b>METHODS</b>To establish the 5/6 nephrectomy rats model and divide the experiment into 3 groups, sham operated group(Sham), 5/6 nephrectomy model group(NTX) and 5/6 nephrectomy with amiloride-treated group (NTX+amiloride, n=15). The concentration of protein and mRNA of uPAR and the change of podocytes motility were detected by coomassiebluestaining, immunofluorence method and real-time PCR.</p><p><b>RESULTS</b>At second week, compared with Control group, the 24 h urine protein of NTX group was significantly increased (47.50 ± 28.05 mg vs 14.28 ± 3.8 mg, P = 0.023). There was no statistical significance in 24-hour urine protein between NTX+amiloride group and NTX group (51.56 ± 21.03 mg vs 47.50 ± 28.05 mg, P = 0.748). The same situation was also observed at the time point of 12 week, comparing with NTX group, 24-hour urine protein decreased in Sham group (188.31 ± 29.82 mg vs 21.32 ± 8.59 mg, P = 0.000) and NTX+amiloride group (188.31 ± 29.82 mg vs 121.37 ± 31.14 mg, P=0.000), with statistical significance when comparing with Sham group, the expression of uPAR mRNA in NTX group was significantly increased (9.74 ± 1.44 vs 1.01 ± 0.13, P = 0.000). In contrast, the expression of uPAR mRNA in NTX rats treated with amiloride was significantly lower than in NTX group (9.74 ± 1.44 vs 5.01 ± 1.36, P = 0.000).</p><p><b>CONCLUSION</b>Amiloride can reduce the proteinuria of the 5/6 nephrectomy rats model of transient proteinuria by inhibiting the induction of uPAR expression.</p>

Acute Hypoxia Activates an ENaC-like Channel in Rat Pheochromocytoma (PC12) Cells

Cells can resist and even recover from stress induced by acute hypoxia, whereas chronic hypoxia often leads to irreversible damage and eventually death. Although little is known about the response(s) to acute hypoxia in neuronal cells, alterations in ion channel activity could be preferential. This study aimed to elucidate which channel type is involved in the response to acute hypoxia in rat pheochromocytomal (PC12) cells as a neuronal cell model. Using perfusing solution saturated with 95% N2 and 5% CO2, induction of cell hypoxia was confirmed based on increased intracellular Ca2+ with diminished oxygen content in the perfusate. During acute hypoxia, one channel type with a conductance of about 30 pS (2.5 pA at -80 mV) was activated within the first 2~3 min following onset of hypoxia and was long-lived for more than 300 ms with high open probability (Po, up to 0.8). This channel was permeable to Na+ ions, but not to K+, Ca+, and Cl- ions, and was sensitively blocked by amiloride (200 nM). These characteristics and behaviors were quite similar to those of epithelial sodium channel (ENaC). RT-PCR and Western blot analyses confirmed that ENaC channel was endogenously expressed in PC12 cells. Taken together, a 30-pS ENaC-like channel was activated in response to acute hypoxia in PC12 cells. This is the first evidence of an acute hypoxia-activated Na+ channel that can contribute to depolarization of the cell.

Antinociceptive Effects of Amiloride and Benzamil in Neuropathic Pain Model Rats

Amiloride and benzamil showed antinocicepitve effects in several pain models through the inhibition of acid sensing ion channels (ASICs). However, their role in neuropathic pain has not been investigated. In this study, we investigated the effect of the intrathecal amiloride and benzamil in neuropathic pain model, and also examined the role of ASICs on modulation of neuropathic pain. Neuropathic pain was induced by L4-5 spinal nerve ligation in male Sprague-Dawley rats weighing 100-120 g, and intrathecal catheterization was performed for drug administration. The effects of amiloride and benzamil were measured by the paw-withdrawal threshold to a mechanical stimulus using the up and down method. The expression of ASICs in the spinal cord dorsal horn was also analyzed by RT-PCR. Intrathecal amiloride and benzamil significantly increased the paw withdrawal threshold in spinal nerve-ligated rats (87%+/-12% and 76%+/-14%, P=0.007 and 0.012 vs vehicle, respectively). Spinal nerve ligation increased the expression of ASIC3 in the spinal cord dorsal horn (P=0.01), and this increase was inhibited by both amiloride and benzamil (P<0.001 in both). In conclusion, intrathecal amiloride and benzamil display antinociceptive effects in the rat spinal nerve ligation model suggesting they may present an alternative pharmacological tool in the management of neuropathic pain at the spinal level.

A Case of Lithium-Induced Nephrogenic Diabetes Insipidus and Rhabdomyolysis / 대한내과학회지

A 59-year-old woman was admitted to our hospital with polydipsia and general weakness. She had a 30-year history of bipolar disorder and was being treated with risperidone (4 mg/day) and lithium carbonate (1,200 mg/day). During her time in hospital, her urine output and serum osmolality increased, and her urine osmolality decreased. She was found to have myoglobulinuria, an elevated creatine kinase level, and abnormal renal function. Based on these findings, the patient was diagnosed with diabetes insipidus and rhabdomyolysis secondary to lithium therapy. After fluid therapy and the withdrawal of lithium, her clinical symptoms improved significantly. Her urine volume decreased gradually after treatment with amiloride. The effects of lithium on the muscle system are unknown. Hyperosmolarity caused by lithium-induced diabetes insipidus is considered a contributing factor in rhabdomyolysis.

Effect of Amiloride to Retinal Toxicity Induced by Tissue Plasminogen Activator

PURPOSE: The effects of amiloride on cellular toxicity caused by tissue plasminogen activator (tPA) in mouse primary retinal cells were investigated. METHODS: Primary retinal cell cultures were maintained using glial conditioned medium. Commercial tPA and L-arginine were added, and the level of cyclic guanosine monophosphate (cyclic-GMP) in the culture supernatant was assessed using an ELISA assay. We measured the cell viability of cultured retinal cells pretreated with three different concentrations of amiloride (1, 10, and 100 microm) in addition to commercial tPA or L-arginine treatment. RESULTS: After exposing the cultured mouse retinal cells to tPA plus L-arginine or L-arginine alone, cyclic-GMP concentrations were 61.9 +/- 5.1 pmole/mL and 63.1 +/- 6.1 pmole/mL, respectively. However, the control group had a significantly lower concentration of cyclic-GMP (37.2 +/- 3.4 pmole/mL, p < 0.01). The cyclic GMP-dissolved solution did not cause retinal cell death. In the control group and the group treated with 1 microm amiloride and tPA containing L-arginine, the cell viability was 43.7% and 44.5%, respectively. However, cell viability increased to 70.6% with 10 microm amiloride and 78.4% with 100 microm amiloride (p = 0.015). CONCLUSIONS: L-arginine increases intracellular cyclic-GMP and may give rise to retinal cells through this mechanism. In addition, amiloride in concentrations greater than 10 microm protects against L-arginine-induced retinal cell death.

A Case of Lithium-Induced Nephrogenic Diabetes Insipidus and Rhabdomyolysis / 대한내과학회지

A 59-year-old woman was admitted to our hospital with polydipsia and general weakness. She had a 30-year history of bipolar disorder and was being treated with risperidone (4 mg/day) and lithium carbonate (1,200 mg/day). During her time in hospital, her urine output and serum osmolality increased, and her urine osmolality decreased. She was found to have myoglobulinuria, an elevated creatine kinase level, and abnormal renal function. Based on these findings, the patient was diagnosed with diabetes insipidus and rhabdomyolysis secondary to lithium therapy. After fluid therapy and the withdrawal of lithium, her clinical symptoms improved significantly. Her urine volume decreased gradually after treatment with amiloride. The effects of lithium on the muscle system are unknown. Hyperosmolarity caused by lithium-induced diabetes insipidus is considered a contributing factor in rhabdomyolysis.

Uridine-5'-Triphosphate Stimulates Chloride Secretion via Cystic Fibrosis Transmembrane Conductance Regulator and Ca2+-Activated Chloride Channels in Cultured Human Middle Ear Epithelial Cells / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nucleotide binding to purinergic P2Y receptors contributes to the regulation of fluid and ion transport in the middle ear epithelial cells. Here, we investigated the regulatory mechanism of the P2Y2 receptor agonist, uridine-5'-triphosphate (UTP), on Cl- transport in cultured normal human middle ear epithelial (NHMEE) cells. MATERIALS AND METHOD: Electrophysiological measurements were performed in monolayers of cultured NHMEE cells. Short circuit currents (Isc) were measured from the cells mounted in Ussing chambers under various conditions. RESULTS: Apical addition of UTP in presence of amiloride evoked a transient rise and a sustained response in Isc due to Cl- efflux. Application of different Cl- channel blockers to the apical side of the cells significantly decreased UTP-induced Isc. Niflumic acid (NFA), a known blocker of Ca(2+)-activated chloride channels (CACC), and CFTRinh172, a selective inhibitor of cystic fibrosis transmembrane conductance regulator (CFTR), partially inhibited the UTP-induced Cl- secretion, respectively. CONCLUSION: Cl- transport across the airway epithelia plays a predominant role in regulating airway hydration. In this study, UTP is shown to increase both CACC and CFTR-dependent Cl- secretion in NHMEE cells, suggesting their role in fluid and ion transport in the middle ear epithelium.

Effect of aldosterone on the amplification of oncolytic vaccinia virus in human cancer lines / 대한간학회지

BACKGROUND/AIMS: JX-594 is an oncolytic virus derived from the Wyeth vaccinia strain that causes replication-dependent cytolysis and antitumor immunity. Starting with a cross-examination of clinical-trial samples from advanced hepatocellular carcinoma patients having high levels of aldosterone and virus amplification in JX-594 treatment, we investigated the association between virus amplification and aldosterone in human cancer cell lines. METHODS: Cell proliferation was determined by a cell-counting-kit-based colorimetric assay, and vaccinia virus quantitation was performed by quantitative polymerase chain reaction (qPCR) and a viral plaque assay. Also, the intracellular pH was measured using a pH-sensitive dye. RESULTS: Simultaneous treatment with JX-594 and aldosterone significantly increased viral replication in A2780, PC-3, and HepG2 cell lines, but not in U2OS cell lines. Furthermore, the aldosterone treatment time altered the JX-594 replication according to the cell line. The JX-594 replication peaked after 48 and 24 hours of treatment in PC-3 and HepG2 cells, respectively. qPCR showed that JX-594 entry across the plasma membrane was increased, however, the changes are not significant by the treatment. This was inhibited by treatment with spironolactone (an aldosterone-receptor inhibitor). JX-594 entry was significantly decreased by treatment with EIPA [5-(N-ethyl-N-isopropyl)amiloride; a Na+/H+-exchange inhibitor], but aldosterone significantly restored JX-594 entry even in the presence of EIPA. Intracellular alkalization was observed after aldosterone treatment but was acidified by EIPA treatment. CONCLUSIONS: Aldosterone stimulates JX-594 amplification via increased virus entry by affecting the H+ gradient.

Renal Expression of Ammonia Transporters in Rats with Amiloride-Induced Renal Tubular Acidosis / 대한내과학회지

BACKGROUND/AIMS: Renal tubular acidosis (RTA) decreases the net acid excretion, predominantly due to a decrease in urinary ammonia excretion. This study examined whether this decrement is associated with changes in the renal expression of the ammonia transporter family members, Rh B glycoprotein (Rhbg) and Rh C glycoprotein (Rhcg), in rats with amiloride-induced RTA. METHODS: Male Sprague-Dawley rats were treated intraperitoneally with amiloride (3 mg/kg/day) for 6 days. Rhbg and Rhcg expression was evaluated by immunoblotting and immunohistochemistry. Cell height, total cellular expression, expression in the apical 25% of the cell, and apical expression as a percentage of total expression were quantified using immunohistochemistry with quantitative morphometric analysis. RESULTS: After amiloride treatment for 6 days, the serum bicarbonate level was decreased, and serum potassium was increased. The total urinary ammonia excretion and potassium excretion were decreased. The total Rhbg and Rhcg protein expression levels were not changed in the cortex or outer medulla of the kidney. Light microscopy and immunohistochemistry with quantitative morphometric analysis demonstrated that total Rhcg expression was decreased in the cortical collecting duct (CCD) and outer medullary collecting duct (OMCD) in amiloride-induced RTA, whereas Rhbg immunoreactivity was unchanged. CONCLUSIONS: Rats with amiloride-induced RTA have decreased urinary ammonia excretion associated with decreased Rhcg expression in the CCD and OMCD, suggesting that the ammonia transporter Rhcg plays an important role in the pathogenesis of amiloride-induced RTA.

Comparison of mechanisms and cellular uptake of cell-penetrating peptide on different cell lines / 药学学报

Cell-penetrating peptide (CPP) can be used in pharmaceutics as a highly efficient drug delivery transporter. In this study, four tumor cell lines (MCF-7, MDA-MB-231, C6, and B16F10) were used to observe the uptake of fluorescein isothiocyanate (FITC) labeled CPP and the effects of time and concentration of CPP on cell penetration was studied. The CPP exocytosis on C6 cell line was observed, and its exocytosis kinetics was described by zero order equation. In addition, low-temperature condition (4 degrees C) and endocytosis inhibitors were utilized to investigate the mechanism of CPP uptake by cells. Low-temperature condition did not show significantly inhibition on CPP uptake. Heparin, a membrane glycoprotein receptor inhibitor, showed strong inhibition effect (only 3%-10% of the control) on CPP uptake. Chlorpromazine, chloroquine and 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) showed little effect on CPP uptake. This study indicated that CPP penetration had little selectivity on cell type, but the amount and rate of CPP penetration into cells were related to the type of cell lines. The adsorption of CPP on cell membrane induced by sulfate proteoglycan plays an important role on CPP penetration.

Effect of terbutaline on sodium transport in alveolar type I and type II cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of terbutaline on sodium transport in rat alveolar type I (ATI) and type II (ATII) cells of rats.</p><p><b>METHODS</b>The whole cell currents were recorded from ATII cells isolated from rat lungs perfused with or without amiloride (inhibitor of epithelial sodium channel) and ZnCl(2) (inhibitor of cyclic nucleotide-gated cation channel) in the whole cell recording mode using the patch-clamp technique. The effect of terbutaline on the currents was examined.</p><p><b>RESULTS</b>The main currents recorded from ATII cells were amiloride-sensitive and Zn(2+)-sensitive. The amiloride-sensitive and Zn(2+)-sensitive current shared a similar proportion (P>0.05). Both currents could be significantly increased by terbutaline (P<0.05), and the proportion of amiloride-sensitive current was 1.7 times that of Zn(2+)-sensitive current (P<0.05).</p><p><b>CONCLUSION</b>There are functional epithelial sodium channels (ENaC) and cyclic nucleotide-gated cation channels (CNG) on freshly isolated ATII cells, both serving as the main channels for sodium transport. Terbutaline increases the absorption of alveolar fluid primarily by increasing sodium transport of ENaC and CNG on ATI and AT II cells.</p>

Comparative efficacy of amlodipine and hydrochlorthiazide-amiloride in cases of mild essential hypertension in outdoor patients at combined Military Hospital Multan

To compare antihypertensive effect of fixed dose combination Hydrochlorothiazide-Amiloride and Amlodipine in patients of mild essential hypertension. Randomized controlled trial [RTC]. Department of Medicine Combined Military Hospital Multan Cantt from 29 January 2007 to 29 June 2007. After fulfilling the inclusion criteria of mild essential hypertension, defined as per recommendations of Seventh Joint National Committee [JNC 7] for treatment of Hypertension as stage 1 hypertension, systolic blood pressure [SBP] >/= 140-159-mmHg and Diastolic blood pressure[DBP] >/= 90-99-mmHg, 100 patients were randomized into two study groups using a table of random numbers. Group 1 received tab amlodipine [5 mg] and Group 2 received tab hydrochlorothiazide-amiloride [25 mg-2.5mg]. Informed written consent was taken. The patients were followed on subsequent visits [6 in total] for five months and systolic and diastolic blood pressure was recorded carefully. All the data thus obtained were processed and analyzed using SPSS version 10.0. Mean and standard deviation [SD] were calculated for age, diastolic and systolic blood pressure. In group 1 the drop in mean SBP between first and last visit was 15.42 mm Hg. In group 2 the drop in mean SBP between first and last visit was 18.34 mm Hg. In group 1, the drop in mean DBP between first and last visit was 10.08 mm Hg. In group 2 the drop in mean DBP between first and last visit was 14.65 mmHg. Mean drop in SBP of both the groups were compared with each other and found to be significantly different [P=0.003]. Similarly mean drop in DBP of both the groups were compared with each other and found to be significant statistically [P=0.001]. Hydrochlorothiazide-Amiloride had significantly better antihypertensive effect than Amlodipine in patients of mild essential hypertension at the end of five months therapy

Myocardial protection by Ethyl-isopropyl amiloride, a specific NA[+] -H[+] exchange inhibitor, following hemorrhagic shock

Hemorrhagic shock and resuscitation is well known to result in myocardial dysfunction and injury. Stimulation of the Na[+] -H[+] exchanger plays an important role in the pathway of myocardial injury. The purpose of the present study was to examine the protective effects of blocking the cardiac Na[+] -H[+] exchange, using 100mM ethyl-isopropyl amiloride [EIPA], a specific Na[+] -H[+] exchanger blocker, on myocardial contractile function on ex vivo resuscitation of isolated rat heart following one hour of hemorrhagic shock. Sprague- Dawley rats were assigned to hemorrhage, hemorrhage + EIPA, sham hemorrhage and sham hemorrhage + EIPA groups. Rats were hemorrhaged for one hour. Hearts were harvested and ex vivo treated and resuscitated by perfused in the Langendorff System. Myocardial function was determined. The results showed that inhibition of the Na[+] -H[+] exchanger using EIPA improved the post-resuscitation myocardial contractile function. Blocking the Na[+] -H[+] exchanger using 100mM EIPA following 60 minutes of hemorrhagic shock improved myocardial function

Effect of Huoxiang-zhengqi liquid on HCO(3)(-) secretion by intact porcine distal airway epithelium / 生理学报

The short-circuit current (I(SC)) technique was used to examine the effects of cAMP-evoking agents, forskolin/IBMX, and a Chinese medicinal formula, Huoxiang-zhengqi liquid (HZL) on HCO(3)(-) secretion by intact porcine distal airway epithelium. The freshly isolated airway epithelial tissue displayed a transepithelial basal current of (94.9±8.2) μA/cm(2), 16.6% and 62.7% of which was inhibited by amiloride (epithelial Na(+) channel blocker, 100 μmol/L) and NPPB (cystic fibrosis transmembrane conductance regulator Cl(-) channel blocker, 100 μmol/L). Substitution of Cl(-) with impermeable gluconate(-) in the K-H bath solution resulted in a basal current of (54.0±6.7) μA/cm(2), which could be abolished by further removal of HCO(3)(-) in the solution, indicating HCO(3)(-) secretion under unstimulated conditions. Application of forskolin/IBMX (10 μmol/L/100 μmol/L) stimulated an increase of (13.8±1.9) μA/cm(2) in I(SC) which could be blocked by Cl(-) channel inhibitor DPC. With Cl(-) and Cl(-)/HCO(3)(-) substitution, forskolin/IBMX evoked an increase of (7.3±0.5) μA/cm(2) in HCO(3)(-)-dependent, DPC-inhibitable I(SC) (I(HCO(3))). Noticeably, basolateral application of HZL (10 μL/mL) in normal K-H solution evoked an I(SC) of (15.9±2.4) μA/cm(2). The EC(50) of this I(SC) was (6.1±1.4) μL/mL. When substituting Cl(-), HZL stimulated an increase of (7.4±1.9) μA/cm(2) in I(HCO(3)), suggesting HZL-induced HCO(3)(-) secretion. After pretreating the epithelial tissues with forskolin/IBMX in Cl(-)-free K-H solution, HZL induced a further increase of (8.4±0.9) μA/cm(2) in I(HCO(3)), and pretreating tissues with HZL did not significantly affect the subsequent forskolin/IBMX-induced I(HCO(3)) response, indicating that HZL- and forskolin/IBMX-induced I(HCO(3)) responses appeared to be independent and be most likely mediated via different cellular mechanisms. Our results suggest that HCO(3)(-) can be secreted by porcine distal airway epithelium under unstimulated and stimulated conditions, and the stimulatory effect of HZL on HCO(3)(-) secretion in the distal airway epithelium shows HZL to be a hopeful new agonist for distal airway HCO(3)(-) secretion that could be of therapeutic significance.