Changes of Tissue Inhibitors of Metalloproteinase Expression by Transient Receptor Potential Melastatin-Subfamily Member 7 Suppression in Renal Cancer Cells

Purpose@#Recent studies have shown that transient receptor potential melastatin-subfamily member 7 (TRPM7) may enhance cancer cell growth, migration and invasion of human renal cell carcinoma (RCC). We investigated how TRPM7 regulated progression of RCC by interacting with matrix metalloproteinase (MMP)/tissue inhibitors of metalloproteinase (TIMP) pathway. @*Materials and Methods@#We performed a wound healing assay and a transwell migration to examine the migration of RCC cells and transwell invasion assay to assess the invasion of RCC cells. Western blot analysis was used to show the expression of MMP-2, MMP-9, TIMP-1, and TIMP-2. @*Results@#The migration and invasion of RCC cells were markedly suppressed by siRNA targeting TRPM7. Lowering of TRPM7 increased MMP-2 expression and induced no change in MMP-9 expression. Strikingly, TRPM7 silencing suppressed the expression of TIMP-1 and TIMP-2. @*Conclusions@#These results suggested that MMP-independent action of TIMPs may take part in the enhancing effect of TRPM7 on the progression of RCC. (Korean J Urol Oncol 2020;18:61-67)

Histone deacetylase inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats

CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats.

Is the Expression of p53, c-erb-B2 and Ki-67 Influence the Prognosis of the Non-muscle Invasive Urothelial Bladder Cancer?

PURPOSE: The immunohistochemial markers can be used to predict prognosis more accurately for several cancers. In non-muscle invasive urothelial carcinoma, p53, c-erb-B2 and Ki-67 are applicable. We investigated a retrospective analysis of the relation between the markers and clinical prognostic factors of urothelial bladder cancer. MATERIALS AND METHODS: Data from 268 non-muscle invasive urothelial bladder cancer (Ta, T1) patients from one single center were collected. Immunohistochemical evaluation was carried out on 268 (p53, c-erb-B2, Ki-67) cases. Clinical prognostic factors are as follows; number of tumor, tumor invasiveness, tumor grade and recurrence. The sum of all positivity of 3 markers was made as a new factor and evaluation of correlation between this factor and prognostic factors was also done. Statistical analysis was done by chi-squares test and Pearson's correlation test. RESULTS: Through chi-square test, there were significant relations between all markers and tumor invasiveness (p<0.001), tumor grade (p<0.001). Number of tumor is significantly related with Ki-67 (p=0.043). Recurrence is related with c-erb-B2 (p=0.010) and Ki-67 (p=0.043). There was also significant correlations between the sum of the markers and prognostic factors-tumor invasiveness (p<0,001), tumor grade (p<0.001) and recurrence (p=0.007). CONCLUSIONS: In this study, evaluated markers were closely related with clinical prognostic factors and may contribute to decision making on risk-assessment and management strategy for non-muscle invasive urothelial bladder cancer.

17Beta-Estradiol Inhibits Calcium-Activated Potassium Channel Expressions in Rat Whole Bladder / 대한배뇨장애요실금학회지

PURPOSE: To investigate the effect of estrogen on the expression of calcium-activated potassium (KCa) channels in an overactive bladder rat model. To this end, mRNA and protein levels of KCa channel subtypes in the bladder of ovariectomized rats were measured by reverse transcription polymerase chain reaction and western blotting, respectively. METHODS: Ten-week-old female Sprague-Dawley rats were divided randomly into 3 groups: sham-operated control group (n=11), ovariectomy group (n=11), and the group treated with estrogen after ovariectomy (n=12). Rats in the last group were subcutaneously injected with 17β-estradiol (50 µg/kg) every other day for 2 weeks, whereas rats in the other 2 groups received vehicle (soybean oil) alone. Two weeks after treatment, the whole bladder was excised for mRNA and protein measurements. RESULTS: Protein levels of the large-conductance KCa (BK) channels in the ovariectomy group were 1.5 folds higher than those in the sham-operated control group. However, the protein levels of the other KCa channel subtypes did not change significantly upon bilateral ovariectomy. Treatment with 17β-estradiol after ovariectomy restored BK channel protein levels to the control value. In contrast, BK channel mRNA levels were not significantly affected by either ovariectomy alone or 17β-estradiol treatment. The small-conductance KCa type 3 channel (SK3) mRNA and protein levels decreased to 75% of control levels upon 17β-estradiol treatment. CONCLUSIONS: These results suggest that 17β-estradiol may influence urinary bladder function by modulating BK and SK3 channel expression.

Bee Venom Exerts Neuroprotective Effects on Neuronal Cells and Astrocytes under Hypoxic Conditions Through MAPK Signaling Pathways

PURPOSE: Hypoxic-ischemic brain injuries influence the mechanisms of signal transduction, including mitogen-activated protein kinase (MAPK) that regulates gene expression through transcription factor activity. Several attempts have been made to use bee venom (BV) to treat neurological diseases. However, limited data are available for brain injuries such as neonatal hypoxic-ischemic encephalopathy (HIE) and neurodegenerative disorders. The purpose of this study was to investigate the neuroprotective effects of BV by determining the expression of activated MAPK pathways. METHODS: We examined activation and cell viability in hypoxia (1% O2, 5% CO2, 94% N2) in low glucose-treated (H+low G) neuronal cells and astrocytes in the presence and absence of BV. After they were subjected to hypoxic conditions and treated with low glucose, the cells were maintained for 0, 6, 15, and 24 h under normoxic conditions. RESULTS: Extracellular-signal-regulated kinases 1/2 (ERK1/2), p38 MAPK, and stress-activated protein kinases (SAPK)/Jun amino-terminal kinases (JNK) were activated in H+low G conditions. Particularly, phosphorylation of ERK1/2 was maximized 6 h after exposure to H+low G condition. BV specifically inhibited the phosphorylation of ERK1/2. However, BV had no effect on p38 MAPK or SAPK/JNK. In addition, BV improved neuronal cell and astrocytes viability following exposure to H+low G. CONCLUSION: ERK inactivation is known to mediate protective effects in hypoxic brain injury. Taken together, these results suggest that treatment with BV may be helpful in reducing hypoxic injury in neonatal HIE through the ERK signaling pathway.

Genetic association of angiogenesis- and hypoxia-related gene polymorphisms with osteonecrosis of the femoral head

Multiple factors have been implicated in the development of osteonecrosis of the femoral head (ONFH). In particular, non-traumatic ONFH is directly or indirectly related to injury of the vascular supply to the femoral head. Thus, hypoxia in the femoral head caused by impaired blood flow may be an important risk factor for ONFH. In this study, we investigated whether genetic variations of angiogenesis- and hypoxia-related genes contribute to an increased risk for the development of ONFH. Candidate genes were selected based on known hypoxia and angiogenesis pathways. An association study was performed using an Affymetrix Targeted Genotyping 3K Chip array with 460 ONFH patients and 300 control subjects. We showed that single nucleotide polymorphisms (SNPs) in the genes TF, VEGFC, IGFBP3, and ACE were associated with an increased risk of ONFH. On the other hand, SNPs in the KDR and NRP1 genes were associated with protection against ONFH. The most important finding was that one SNP (rs2453839) in the IGFBP3 gene was significantly associated with a higher risk of ONFH (P = 0.0061, OR 7.74). In subgroup analysis, most candidate gene variations that were associated with ONFH occurred in the idiopathic subgroup. Among other SNPs, ACE SNPs were associated with steroid-induced ONFH (P = 0.0018-0.0037, OR > 3). Collectively, our findings suggest that genetic variations in angiogenesis- and hypoxia-related genes may help to identify susceptibility factors for the development of ONFH in the Korean population.

Antimicrobial Effects of Nano-Silver Gauze against Common Bacterial Isolates / 병원감염관리

BACKGROUND: Silver has been used for disinfection and sterilization. We aimed to confirm the in-vitro antibacterial effects of nanocrystalline silver-coated gauze. METHODS: Fourteen clinical isolates each of Escherichia coli and Acinetobacter baumannii were used. Bacterial suspensions made in tryptic soy broth were exposed to Ordinary and silver-coated gauze. Bacteria were then harvested from the gauze immediately and after 24 h incubation, cultured on blood agar plates and eunmerated for viable counts. The number of colonies was converted into common logarithms for comparison. RESULTS: The number of colonies recovered from silver-coated gauze was significantly lower than those recovered from ordinary gauze when harvested immediately after exposure (E. coli, 3.06 vs 1.73; A. baumannii, 3.13 vs 1.98; P<0.001). After 24 h incubation of exposed gauze, silver-coated gauze produced less than 1 CFU/mL, whereas ordinary gauze produced a number of colonies significantly higher than it did immediately after exposure (E. coli, 4.13; A. baumannii, 4.46; P<0.001). Conclusion: Compared with ordinary gauze, silver-coated gauze was shown to have 99.99% antibacterial effect.

Downregulation of Peroxisome Proliferator-Activated Receptor (PPAR)alpha, PPARgamma, and Phosphoglycerate Mutase 2 in Prostate Cancer / 대한비뇨기과학회지

PURPOSE: To evaluate whether factors related to lipid and glucose metabolism have a potential role in the progression of prostate cancer, we measured the mRNA levels of the peroxisome proliferator-activated receptor (PPAR), fatty acid elongase (ELOVL), and two glycolytic enzymes in prostate cancer (CaP) tissues. MATERIALS AND METHODS: Prostate tissues, obtained from radical prostatectomy (n=10) and transurethral resection of prostate (n=18), were quickly frozen in liquid nitrogen for RNA measurements. Transcript signals of PPAR alpha, PPAR gamma, ELOVL2, ELOVL5, phosphoglycerate kinase 1 (PgK1) and phosphoglycerate mutase 2 (PgM2) were measured using a reverse-transcription polymerase chain reaction. RESULTS: The transcript signals of PPAR alpha and PPAR gamma were down-regulated in CaP tissues. In addition, the mRNA level of PgM2 in CaP tissues was lower than that in benign prostatic hyperplasia (BPH) tissues. However, the messages for ELOVL2, ELOVL5, and PgK1 were not significantly changed. CONCLUSIONS: These results suggest that lowering of the PPARalpha, PPARgamma and PgM2 messages may be involved in aberrant and uncontrolled prostate cell growth and differentiation.

Altered Expressions of Calcium-Activated Potassium Channel and Connexin in Bladder Mucosae of Stress Urinary Incontinence Patients with Overactive Bladder Symptoms / 대한비뇨기과학회지

PURPOSE: The aim of this study was to examine how the mRNA and protein levels of calcium activated Kchannel (K(Ca)) and connexin (Cx) change in association with overactive bladder in the bladder mucosae of stress urinary incontinence (SUI) patients. MATERIALS AND METHODS: Twenty SUI patients were included in our study. Bladder mucosae were obtained, with using cold cup biopsy forceps, from the patients suffering with genuine stress urinary incontinence (group 1, n=7), from the patients suffering with SUI along with urgency and frequency (group 2, n=6), and from the patients suffering with mixed incontinence (group 3, n=7). RESULTS: The mRNA transcripts of type 2 (SK2) and type 3 (SK3) small conductance K(Ca), Cx26, and Cx43 were highly expressed in the bladder mucosa. The message of large conductance K(Ca)(BK) was significantly decreased in group 3 compared with that in the controls. The SK2 and Cx26 messages in group 3 were also lower than those in groups 1 and 2. In the presence of urge incontinence, the BK and SK2 protein levels were decreased and the Cx26 protein expression was significantly increased in the bladder mucosa of the SUI patients. In contrast, there were no significant differences in the mRNA and protein levels of K(Ca)s and Cxs between groups 1 and group 2. CONCLUSIONS: Downregulation of both BK and SK2 and upregulation of Cx26 in the bladder mucosa of MI patients may contribute to the alterations of urothelial instability, and this correlate with the symptom severity of bladder instability in SUI patients.

Involvement of ERK1/2 and JNK Pathways in 17beta-estradiol Induced Kir6.2 and SK2 Upregulation in Rat Osteoblast-like Cells

The functional expression of potassium (K+) channels has electrophysiologically been studied in bone cells from several species, however, their identity and regulation of gene expressions in bone cells are not well known. In the present study, to investigate how K+ channel expressions are regulated by estrogen, we measured changes of transcript levels of various Ca2+-activated (K(Ca)) and ATP-sensitive K+ channels in rat osteoblastic ROS 17/2.8 cells after treatment with estrogen. Application of 17beta-estradiol (E2) for 24 h and 48 h increased mRNA and protein expressions of inwardly rectifying K+ channel (Kir) 6.2 and type 2 small conductance K(Ca) channel (SK2), respectively. Combined treatment of cells with 17beta-E2 and ICI 182,780, a pure antiestrogen, suppressed 17beta-E2-induced alterations of SK2 and Kir6.2 mRNA levels. In addition, treatment of cells with U0126, a specific inhibitor of extracellular receptor kinases (ERK)1/2, and SP600125, a specific inhibitor of c-jun N-terminal kinase (JNK) blocked the enhancing effects of 17beta-E2 on SK2 and Kir6.2 protein expressions. On the other hand, blocking of p38 mitogen-activated protein kinase had no effect. Taken together, these results indicate that 17beta-E2 modulates SK2 and Kir6.2 expressions through the estrogen receptor, involving ERK1/2 and JNK activations.

Evaluation of Automatic Acid-Fast Bacilli Stainer AT-2000F / 대한임상미생물학회지

BACKGROUND: Sputum smear microscopy is rapid, economic, and useful to detect patients with transmittable tuberculosis, albeit laborious. We aimed to evaluate the usefulness of an automated acid-fast bacilli stainer, which had been developed for lowering the labor and maintaining or increasing the staining quality. METHODS: One hundred sputum samples including some known positive smear specimens which were selected from clinical specimens requested for smear and culture for mycobacteria at Pusan National University Hospital, were used for evaluation. Auramine/rhodamine fluorescent acid-fast stainings were performed manually or by using the automated stainer, AT-2000F (Dagatron, Ilsan, Korea). Ziehl-Neelsen stain was also performed simultaneously. RESULTS: Concordance rate between automated and manual fluorescent stains was 98.0% and that between automated fluorescent and manual Ziehl-Neelsen stains was 88.0%. In all discordant cases, the automated stains showed one-grade higher results compared to the respective manual fluorescent or Ziehl-Neelsen stains. With the automatic stainer, all staining procedures were processed automatically except for slide loading and unloading. The process time was reduced by a half, and the slide-to-slide or day-to-day variations of staining quality were reduced compared with the manual fluorescent stain. CONCLUSION: Acid-fast bacilli stain using automated stainer AF-2000F can reduce the processing time, labor, and variations of staining quality, and enhance or maintain the detection of positive smears.

Alterations in Calcium-Activated Potassium Channel Expressions in Human Prostate Cancer / 대한비뇨기과학회지

PURPOSE: Recent studies have shown that potassium (K+) and sodium channels are involved in prostate cell growth. However, a great many of the studies have been done in prostate cancer cell lines and there are only scant studies on prostate cancer and benign prostatic hypertrophy (BPH) tissue. The present study was aimed to evaluate the alterations of the calcium-activated K+ channel (KCa) expression in prostate cancer, and to compare them with the expression profiles in human BPH tissue to understand their potential role in the progression of prostate cancer. MATERIALS AND METHODS: The prostate tissues obtained from radical prostatectomy (n=10) and transurethral resection of the prostate (n=18) were quickly frozen in liquid nitrogen for the RNA measurements. The protein and mRNA levels of the KCa subtypes and connexins were measured by performing immunoblot analysis and reverse-transcription polymerase chain reaction, respectively. RESULTS: The mRNA levels of type 2 (SK2) and type 3 (SK3) small-conductance and large-conductance (BK) KCas in the prostate cancer tissues were decreased more than 50% compared with those in the BPH samples. In addition, the BK and SK2 protein levels in prostate cancer were also significantly lower than those in the BPH. As reported previously, the connexin 26 and 43 transcript signals in the prostate cancer were significantly reduced compared with those in the BPH samples. CONCLUSIONS: These results suggest that the impaired expression of KCas may have a role in tumor progression via aberrant and uncontrolled prostate cell growth.

Antimicrobial Activities of Arbekacin against Recent Isolates of Staphylococcus aureus in Korean Hospitals / 대한임상미생물학회지

BACKGROUND: As clinical isolates of Staphylococcus aureus with reduced inhibition zone of arbekacin in disk diffusion susceptibility tests are observed frequently, we examined their susceptibility to the antibiotic by comparing the results of the agar dilution testing with those of disk diffusion testing. METHODS: During the period of May through July, 2004, 88 isolates of methicillin-resistant and 11 methicillin-susceptible S. aureus were collected from clinical specimens in Pusan National University Hospital and Kosin University Gospel Hospital. Minimal inhibitory concentrations (MICs) of arbekacin were determined by the agar dilution method, and inhibition zones by the disk diffusion method. RESULTS: All of the 99 isolates were tested susceptible to arbekacin by the agar dilution method (MIC < or = 8 mg/L). By the disk diffusion method, however, 5 isolates (5.1%) were intermediate (minor error) and 2 isolates (2.0%) resistant (major error). CONCLUSION: All isolates were susceptible to arbekacin, but the disk diffusion method showed 7 per cent of minor or major errors.

Effect of Green Tea on Calcium Oxalate Stone Formation and Excretion in Ethylene Glycol-treated Rats / 대한비뇨기과학회지

PURPOSE: To evaluate the therapeutic potential of green tea to treat renal stone, we examined the effect of green tea on the formation and the excretion of experimentally induced calcium oxalate (CaOx) stones in rat kidneys. MATERIALS AND METHODS: CaOx nephrolithiasis was induced by administering 1% ethylene glycol (EG) for 4 weeks. To investigate the effect of tea on the formation CaOx stones, the rats were simultaneously administered either 0.2% green tea or 0.5% rooibos tea. To verify the action of green tea on the excretion of CaOx stones, the rats were divided into four groups after the administration of 1% EG water for 4 weeks and then fed with either 0.2% green tea, 0.5% rooibos tea or 80mg/l furosemide-containing 1% EG water for 4 weeks. The right kidney was frozen for mRNA measurements, with the left fixed for counting crystal deposits. Twenty-four hour urine volume and urinary excretions of oxalate, uric acid, calcium and magnesium were measured. RESULTS: Urinary biochemistry and 24 hour urine output were apparently unchanged by taking either the green tea or rooibos tea. The increases of CaOx crystal deposits and osteopontin mRNA expressions in the kidneys by the administration of 1% EG water were markedly decreased by both tea intakes, while there were no significant differences in the mRNA levels of CuZn- and Mn-superoxide dismutases between the groups. CONCLUSIONS: Green and rooibos teas significantly attenuated the calcium crystal depositions in the kidneys. Down-regulations of the osteopontin mRNA levels may be involved in the inhibitory effects of the teas on the renal CaOx stone formation.

Estrogen and Enalapril attenuate the Development of Right Ventricular Hypertrophy induced by Monocrotaline in Ovariectomized Rats

The present study evaluated the importance of ovarian functions and the renin-angiotensin system in the progression of the right ventricular (RV) hypertrophy. Female Sprague-Dawley rats were bilaterally ovariectomized (Ovx) and injected with monocrotaline (MCT, 60 mg/kg, sc). Four weeks after MCT-treatment, only the male and Ovx female rats showed marked RV hypertrophy. The hypertrophied RV of the male-MCT and Ovx-MCT rats exhibited remarkably elevated renin mRNA levels. Gene expression levels of angiotensinogen, TGF-beta1, and endothelin-1 in the hypertrophied RV also increased, but to the less degree than did the renin mRNA. To investigate beneficial effects of estrogen or enalapril on progression of the pulmonary hypertension and RV hypertrophy, histological changes of the lung and heart were examined. Sham-MCT female rats showed histological changes indicating pulmonary hypertension without RV hypertrophy. In contrast, Ovx-MCT rats showed marked RV hypertrophy with pathological changes, denoting severe pulmonary and myocardial injuries. Estrogen-or enalapril-treated Ovx-MCT rats did not show RV hypertrophy, and showed remarkably ameliorated ultrastructural changes in the lung and RV. These results from this rat model suggest that both estrogen and inhibition of the renin-angiotensin system have protective functions against the development of the pulmonary hypertension and cardiac remodeling.

Resveratrol derivatives potently induce apoptosis in human promyelocytic leukemia cells

Resveratrol has been shown to possess antioxidant and anticancer activities, but little is known on the effect of resveratrol derivatives. Recently we have isolated resveratrol and its dimers and trimers from peony (Paeonia lactiflora) seeds, and reported their strong antioxidant and cytotoxic activity. In the present study, we have evaluated cellular effects of resveratrol derivatives; viniferin, gnetin H, and suffruticosol B on the proliferation and apoptosis in HL-60 cells in vitro. All resveratrol and its derivatives reduced viability of HL-60 cells in a dose-dependent manner with their IC(50)values of 20-90 micrometer. Ascending orders of IC(50)values were suffruticosol B, gnetin H, viniferin and resveratrol respectively. HL-60 cells treated with the four stilbenes exhibited the distinct morphological changes characteristics of cell apoptosis such as chromatin condensation, apoptotic bodies, and DNA fragmentations. A time-dependent histogram of the cellular DNA analyzed by flow cytometry revealed a rapid increase in subdiploid cells and a concomitant decrease in diploid cells exposed to 100 micrometer resveratrol for 0-24 h. Cells treated with 25 micrometer of resveratrol, viniferin, gnetin H, and suffruticosol B for 24 h resulted in increment of sub-G1 population by 51, 5, 11 and 59%, respectively. Treatment of cells with 0-20 micrometer resveratrol for 5 h produced a concentration-dependent decrease in cytochrome P450 (CYP) 1B1 mRNA levels. Suffruticosol B also suppressed CYP1B1 gene expression. These results demonstrated that resveratrol oligomers also strongly suppressed HL-60 cell proliferation, and induced DNA damage. In addition, CYP1B1 gene supression may suggest an involvement in the resveratrol-induced apoptosis in HL-60 cells.

Role of angiotensin II and nitric oxide in the rat paraventricular nucleus

To investigate the mutual relationship between angiotensin II (Ang II) and nitric oxide (NO) in paraventricular nucleus (PVN), Ang II receptor type Ia (AT1A), type Ib (AT1B), endothelial constitutive nitric oxide synthase (ecNOS), and neuronal constitutive nitric oxide synthase (ncNOS) mRNA levels of rat PVN were measured after unilateral carotid artery ligation. AT1A and AT1B mRNA levels were markedly elevated 6 hrs after unilateral carotid artery ligation. Losartan injection (10 microgram/0.3 microliter) into the PVN augmented of the increment of AT1A and AT1B mRNAs It also increased ecNOS gene expression. In addition, AT1B mRNA levels increased after N-nitro-L-arginine methyl ester (L-NAME) injection (50 microgram/0.3 microliter) into the PVN. These results suggest that Ang II and NO in the rat PVN may interplay, at least in part, through regulation of gene expression of ecNOS and AT1B, respectively.

Pulse exposure to ethanol augments vascular contractility through stress response

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 micromol/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.

Effect of brain angiotensin II receptor antagonists and antisense oligonucleotide on drinking and renal renin in rats

The physiological roles of brain angiotensin II in mediating water deprivation-induced drinking and in regulating renal renin release were assessed in male Sprague-Dawley rats. Specific AT1 receptor antagonists, losartan and SK 1080, and antisense oligonucleotide (AS-ODN) directed to AT1 receptor mRNA were intracerebroventricularly (i.c.v.) administered in conscious unrestrained rats. When water was given 20 min after i.c.v. injection of AT1 receptor antagonists in 48-h water-deprived rats, losartan and SK 1080 produced approximatly 20% and 50% decrease in 1-h water intake, respectively. In contrast, i.c.v. treatment of the AS-ODN to AT1 receptor mRNA for 24-h did not alter 1-h water intake in 24-h water-deprived rats, but prevented the increase in overnight water intake after 24-h water-deprivation. Six-day i.c.v. treatment of AS-ODN did not alter either the basal plasma renin concentration or renal cortical levels of renin and renin mRNA. The present results suggest that endogenous brain Ang II plays an important role in thirst and water intake through AT1 receptors, but further studies are required to elucidate its regulatory role in renal renin synthesis.

Spectral analysis of heart rate variability during passive standing after ethanol ingestion

The purpose of the present study was to evaluate cardiovascular regulation during passive standing (PS) after ethanol ingestion by spectral analysis of heart rate variability (HRV) in flushed and nonflushed subjects. Of 24 young male subjects, 8 belonged to flushed group (F) and 16 to nonflushed group (NF). Two sessions of 10-min PS were performed before and after ethanol (0.5 g/kg) ingestion. Powers of R-R interval variability in very low frequency (VLF, 0~0.05 Hz), low frequency (LF, 0.05~0.15 Hz) and high frequency (HF, 0.15~0.50 Hz) bands, normalized powers (LFn and HFn) and LF/HF ratio were obtained. After ethanol ingestion, F showed higher heart rate than NF. PS increased LFn (+ 22.9+/-3.6 in NF, + 12.8+/-4.7 in F, in normalized units) and LF/HF (+ 3.10+/-0.57 in NF, + 3.00+/-1.08 in F) and decreased HFn powers. Ethanol ingestion increased LFn and LF/HF and decreased HFn. PS after ethanol resulted in higher LFn and LF/HF and lower HFn than the prior PS. F showed a greater and more sustained HRV change than NF after ethanol. In conclusion, PS or ethanol ingestion increased LFn and LF/HF and decreased HFn. Flushed subjects showed an accentuated HRV response to ethanol.