The clinical impact of ureteroscopy for upper tract urothelial carcinoma: A multicenter study

BACKGROUND

With the development of kidney-sparing surgery and neoadjuvant chemotherapy, ureteroscopic biopsy (URSBx) has become important for the management of upper tract urothelial carcinoma (UTUC).

METHODS

We retrospectively analyzed data from 744 patients with UTUC who underwent radical nephroureterectomy (RNU), stratified into no ureteroscopy (URS), URS alone, and URSBx groups. Intravesical recurrence-free survival (IVRFS) was examined using the Kaplan-Meier method. We conducted Cox regression analyses to identify risk factors for IVR. We investigated differences between clinical and pathological staging to assess the ability to predict the pathological tumor stage and grade of RNU specimens.

RESULTS

Kaplan-Meier curves and multivariate Cox regression revealed significantly more IVR and inferior IVRFS in patients who underwent URS and URSBx. Superficial, but not invasive, bladder cancer recurrence was more frequent in the URS and URSBx groups than in the no URS group. Clinical and pathological staging agreed for 55 (32.4%) patients. Downstaging occurred for 48 (28.2%) patients and clinical understaging occurred for 67 (39.4%) patients. Upstaging to muscle-invasive disease occurred for 39 (35.8%) of 109 patients with ≤cT1 disease. Clinical and pathological grading were similar for 72 (42.3%) patients. Downgrading occurred for 5 (2.9%) patients, and clinical undergrading occurred for 93 (54.7%) patients.

CONCLUSION

URS and URSBx instrumentation will be risk factors for superficial, but not invasive, bladder cancer recurrence. Clinical understaging/undergrading and upstaging to muscle-invasive disease occurred for a large proportion of patients with UTUC who underwent RNU. These data emphasize the challenges involved in accurate UTUC staging and grading.

Real-world outcomes of adjuvant immunotherapy candidates with upper tract urothelial carcinoma: results of a multicenter cohort study

BACKGROUND

Recent clinical trials have reported improved disease-free survival rates of patients with stage pT3-4/ypT2-4 or pN + upper tract urothelial carcinoma (UTUC) on adjuvant nivolumab therapy. However, the appropriateness of the patient selection criteria used in clinical practice remains uncertain.

METHODS

We retrospectively analyzed 895 patients who underwent nephroureterectomy to treat UTUC. The patients were divided into two groups: grade pT3-4 and/or pN + without neoadjuvant chemotherapy (NAC) or grade ypT2-4 and/or ypN + on NAC (adjuvant immunotherapy candidates) and others (not candidates for adjuvant immunotherapy). Kaplan-Meier curves were drawn to assess the oncological outcomes, including recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). Cox proportional hazards models were used to identify significant prognostic factors for oncological outcomes.

RESULTS

The Kaplan-Meier curves revealed notably inferior RFS, CSS, and OS of patients who were candidates for adjuvant immunotherapy. Multivariate analysis revealed that pathological T and N grade and lymphovascular invasion (LVI) status were independent risk factors for poor RFS, CSS, and OS.

CONCLUSION

In total, 44.8% of patients were candidates for adjuvant immunotherapy. In addition to pathological T and N status, LVI was a significant predictor of survival, and may thus play a pivotal role in the selection of patients eligible for adjuvant immunotherapy.

The association between neutropenia and prognosis in stage III colorectal cancer patients receiving adjuvant chemotherapy

Neutropenia during chemotherapy has been reported to be a predictor of better survival in patients with several types of cancer, although there are no reports on stage III colorectal cancer (CRC). The purpose of this study was to examine the association between neutropenia and prognosis in stage III CRC patients receiving adjuvant chemotherapy consisting of oral uracil and tegafur (UFT) plus leucovorin (LV). We retrospectively analysed 123 patients with stage III CRC who received UFT/LV as adjuvant chemotherapy. The end-point was disease-free survival (DFS). Survival curves of the two categories (neutropenia absent vs. present) were estimated using the Kaplan-Meier method and compared by the log-rank test. We estimated the hazard ratio (HR) for DFS according to neutropenia after adjustment for covariates by multivariate analyses using Cox's regression analysis. A total of 33 (26.8%) patients experienced neutropenia. Patients without neutropenia showed a significantly lower DFS than those with neutropenia (3-year DFS 57.3% vs. 81.2%, P = 0.0213). By multivariate analysis, neutropenia and histological type were independent prognostic factors, with HR of 0.410 (neutropenia absent vs. present, P = 0.045) and 4.793 (well to moderately differentiated vs. poorly differentiated, P = 0.004) respectively. We demonstrated that neutropenia occurring during adjuvant chemotherapy consisting of UFT/LV may be a prognostic factor of recurrence in stage III CRC patients.

Association study of genetic variants on chromosome 7q31 with susceptibility to normal tension glaucoma in a Japanese population

The caveolin 1 to caveolin 2 (CAV1-CAV2) gene region on chromosome 7q31 has been reported to be associated with susceptibility to primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) in previous studies. We investigated whether genetic variants in the CAV1-CAV2 region are associated with NTG in Japanese patients. Two hundred and ninety-two Japanese patients with NTG and 352 Japanese healthy controls were recruited. We genotyped three single-nucleotide polymorphisms; that is, rs1052990, rs4236601, and rs7795356, in the CAV1-CAV2 gene region and assessed the allelic diversity among cases and controls. The frequency of the minor allele (G) of rs1052990 was significantly decreased in NTG cases compared with controls (P=0.014, OR=0.71), whereas NTG or POAG cases had a significantly higher frequency of the allele than controls in previous studies. Conversely, rs7795356 did not show any significant association with NTG cases, and rs4236601 was monomorphic in the Japanese study population. Our findings did not correspond with previous positive results, suggesting that CAV1-CAV2 variants studied in the present study are not important risk factors for NTG susceptibility in all populations. Further studies are needed to elucidate the possible contribution of the CAV1-CAV2 region to the development of glaucoma.

Ocular volumetry using fast high-resolution MRI during visual fixation

BACKGROUND AND PURPOSE

Volumetry may be useful for evaluating treatment response and prognosis of intraocular lesions. Phantom, volunteer, and patient studies were performed to determine whether ocular MR volumetry is reproducible.

MATERIALS AND METHODS

Half-Fourier single-shot RARE and FSPGR sequences at 1.5T with a 76-mm-diameter surface coil were optimized to obtain still ocular images. Volumetry accuracies of each sequence were compared with simulated subretinal phantom volumes. Ocular volumetry was performed in 15 volunteers twice in 1 week by using contiguous axial images of the globes while the subjects stared at a target, and images were acquired in 2 seconds before the subjects were instructed to blink, with this process repeated as necessary. Imaging, intraobserver, and interobserver reproducibility for volumes of the whole eyeball and anterior chamber were assessed. Ocular volumetry was also performed in 6 patients with intraocular tumors before and after treatment.

RESULTS

The phantom study demonstrated that measurement error rates with RARE were significantly lower than with FSPGR (P<.01). The volunteer study demonstrated excellent imaging and intraobserver reproducibility of RARE volumetry for whole eyeballs and anterior chambers (P<.01). Although no interobserver differences were observed in anterior chamber volume measurement (P=.33), there was a significant difference between the 2 observers in eyeball volume measurement (P<.01). Follow-up volumetric data were useful for treatment decisions in all patients.

CONCLUSIONS

Ocular volumetry from contiguous ultrafast RARE images obtained during visual fixation is feasible in volunteer and patient studies and is superior to FSPGR images.

Investigation of the association between the GLC3A locus and normal tension glaucoma in Japanese patients by microsatellite analysis

Purpose:

To investigate whether the GLC3A locus harboring the CYP1B1 gene is associated with normal tension glaucoma (NTG) in Japanese patients.

Materials and Methods:

One hundred forty-two Japanese patients with NTG and 101 Japanese healthy controls were recruited. Patients exhibiting a comparatively early onset were selected as this suggests that genetic factors may show stronger involvement. Genotyping and assessment of allelic diversity was performed on 13 highly polymorphic microsatellite markers in and around the GLC3A locus.

Results:

There were decreased frequencies of the 444 allele of D2S0416i and the 258 allele of D2S0425i in cases compared to controls (P = 0.022 and P = 0.034, respectively). However, this statistical significance disappeared when corrected (Pc > 0.05). We did not find any significant association between the remaining 11 microsatellite markers, including D2S177, which may be associated with CYP1B1, and NTG (P > 0.05).

Conclusions:

Our study showed no association between the GLCA3 locus and NTG, suggesting that the CYP1B1 gene, which is reportedly involved in a range of glaucoma phenotypes, may not be an associated factor in the pathogenesis of NTG.

Predictors of restenosis after coronary artery stenting

AIM

The aim of this study was to analyze restenosis after percutaneous coronary intervention, factors related to restenosis after coronary artery stenting and the degree of the risk of restenosis were evaluated.

METHODS

The study enrolled 181 patients (249 lesions) who underwent the first coronary artery stenting. Multivariate analysis was performed, and the restenotic index (RI) was calculated by combining the extracted predictors.

RESULTS

Among the 181 patients (249 lesions), restenosis occurred in 89 (111 lesions) and did not occur in 92 (138 lesions). Vascular revasculation was performed in 95 restenosed target lesions in 68 patients. The mean period of follow-up angiography after the procedures was 206 days in the restenosis group and 271 days in the non-restenosis group, i.e. significantly shorter in the restenosis group. As a result of multivariate analysis, diabetes mellitus, Cr level, amount of the contrast medium used and stent diameter were selected as significant factors that independently contributed to the restenosis after coronary artery stenting. By combining these factors, the RI was calculated by the following formula for the prediction of restenosis: RI=exp (1.088xCr+0.909xdiabetes mellitus+0.871xcontrast medium+0.591xstent diameter).

CONCLUSION

The risk of restenosis after coronary artery stenting can be predicted to an extent according to the RI devised in this study.

Evaluation of paraumbilical vein as a prognostic index of severe liver cirrhotic patients with portal-systemic shunts

AIM

The aim of this study was to predict the outcome in severe liver cirrhotic patients with portal-systemic shunts.

METHODS

One-hundred and sixteen patients with liver cirrhosis diagnosed as Child-Pugh class B and C with portal-systemic shunts confirmed by abdominal ultrasonography, computed tomography and magnetic resonance imaging were enrolled in this study. Twenty-three factors were evaluated concerning clinical laboratory parameters and extracted prognostic factors using the Cox proportional hazards model, and the prognostic index (PI) was prepared by combining these factors.

RESULTS

The cumulative survival rates after admission were 64.6%, 35.6% and 25% after 1, 3 and 5 years, respectively. Using multivariate analysis, age, the presence of hepatocellular carcinoma (HCC), portal vein tumor thrombosis (PVTT) and paraumbilical vein (PUV) shunt were selected as significant prognostic factors that contributed independently to the prognosis of severe liver cirrhotic patients with portal-systemic shunts. The PI was calculated with the following formula using these 4 factors. PI = 0.042 x Age + 0.913 x HCC + 0.989 x PVTT + 1.079 x PUV shunt. The group with a high score for PI was found to die with significantly higher frequency than the group with a low score.

CONCLUSIONS

It was found that tumor related factors and PUV shunt were the most important factors for severe liver cirrhotic patients with portal-systemic shunts. The PI is suggested to be an appropriate index to predict the prognosis for these patients.

Interacting molecule of AT1 receptor, ATRAP, is colocalized with AT1 receptor in the mouse renal tubules

The renin-angiotensin system in the kidney plays a critical role in the regulation of renal hemodynamics and sodium handling through the activation of vascular, glomerular and tubular angiotensin II type 1 (AT1) receptor-mediated signaling. We previously cloned a molecule that specifically bound to the AT1 receptor and modulated AT1 receptor signaling in vitro, which we named ATRAP (for AT1 receptor-associated protein). The purpose of this study is to analyze the renal distribution of ATRAP and to examine whether ATRAP is co-expressed with the AT1 receptor in the mouse kidney. We performed in situ hybridization, Western blot analysis, and immunohistochemistry to investigate the expression of ATRAP mRNA and protein in the mouse kidney. The results of Western blot analysis revealed the ATRAP protein to be abundantly expressed in the kidney. Employing in situ hybridization and immunohistochemistry, we found that both ATRAP mRNA and the protein were widely distributed along the renal tubules from Bowman's capsules to the inner medullary collecting ducts. ATRAP mRNA was also detected in the glomeruli, vasculature, and interstitial cells. In all tubular cells, the ATRAP protein colocalized with the AT1 receptor. Finally, we found that the dietary salt depletion significantly decreased the renal expression of ATRAP as well as AT1 receptor. These findings show ATRAP to be abundantly and broadly distributed in nephron segments where the AT1 receptor is expressed. Furthermore, this is the first report demonstrating a substantial colocalization of ATRAP and AT1 receptor in vivo.

Lower haemoglobin level and subsequent decline in kidney function in type 2 diabetic adults without clinical albuminuria

AIMS/HYPOTHESIS

Anaemia has been suggested to be an independent risk factor for subsequent progression of advanced diabetic nephropathy; however, the relationship between haemoglobin levels and progression of nephropathy in patients without clinical albuminuria is unknown.

METHODS

We conducted this prospective hospital-based cohort study of 464 type 2 diabetic patients (149 women and 315 men, 55+/-13 [mean+/-SD] years of age) with serum creatinine <177 micromol/l (2.00 mg/dl) and urinary albumin : creatinine ratio <300 mg/g creatinine. GFR was estimated using the equation formulated by the Modification of Diet in Renal Disease Study group, refitted for Japanese individuals. Most patients had haemoglobin concentrations in the normal range (144+/-15 g/l), only modest renal impairment (GFR: 74.8+/-14.5 ml min(-1) 1.73 m(-2)), and normal urinary albumin levels (81.5/18.5% with normo-/microalbuminuria). The primary outcome measurement was the rate of change in GFR determined by regression analysis with GFR as a function of time. Patients were followed up for a mean observation period of 5.0+/-0.9 (range: 2.5 to 6.2) years.

RESULTS

Univariate and multiple regression analyses yielded a significant association between the rate of change in GFR and baseline haemoglobin concentration. After adjusting for covariates, the rate of decline in GFR was significantly greater in patients in the lowest haemoglobin quartile (-3.27 ml min(-1) 1.73 m(-2) year(-1)) than in the third (-2.71 ml min(-1) 1.73 m(-2) year(-1), p = 0.024) and highest quartiles (-2.78 ml min(-1) 1.73 m(-2) year(-1), p = 0.046).

CONCLUSIONS/INTERPRETATION

Lower haemoglobin concentrations in type 2 diabetic patients without clinical albuminuria may be a significant predictor of subsequent decline in GFR.

Prognostic factors of primary biliary cirrhosis detected by health screening

AIM

The liver cirrhosis is likely to differ in the Japanese and Western populations. Thus, we performed a retrospective cohort analysis by a review of clinical records to clarify prognostic factors after the onset of primary biliary cirrhosis (PBC) detected by health screening.

METHODS

The subjects were 52 patients with PBC. Thirty-nine factors were evaluated concerning clinical data and extracted prognostic factors using the Cox proportional hazard model.

RESULTS

The mean duration of the follow-up period was 5.1 years, during which 6 (11.5%) of the patients died. The cumulative survival rate after the onset of PBC was 93.4% after 5 year, and 67.8% after 10 years. Multivariate analysis indicated 2 factors, i.e. the body mass index (BMI), and IgG, as independent prognostic factors. Their hazard ratios were 0.399 (per 1 kg/m2 of BMI) and 1.282 (per 100 mg/dL of IgG). The prognostic index (PI) was calculated by the following formula using these 2 factors. PI = 0.919 x BMI+0.249 x IgG.

CONCLUSIONS

The prediction of the outcome using PI based on the 2 factors provides additional information for the determination of the therapeutic approach in PBC after health screening.

Antinociceptive efficacy of antidepressants: assessment of five antidepressants and four monoamine receptors in rats

PURPOSE

For assessment of the antinociceptive potency of antidepressants, we compared the antinociceptive effects of serotonin selective reuptake inhibitors (SSRIs) and classical tricyclic antidepressants (TCAs) in rats. We also attempted to elucidate the monoamine receptor subtypes predominantly involved in the antinociceptive effect of antidepressants.

METHODS

Male Wistar rats received SSRIs (sertraline, fluvoxamine, and citalopram) or TCAs (imipramine and desipramine) intraperitoneally, and the reaction time until pain response in the hot plate test and licking time in the formalin test were measured 60 min later. We also observed the effects of prazosin (an alpha(1) antagonist), WB-4101 (a selective alpha(1A) antagonist), yohimbine (an alpha(2) antagonist), WAY-100635 (a selective 5-HT(1A) antagonist), and ketanserin (a 5-HT(2) antagonist), which were simultaneously administered with imipramine or desipramine, on the antidepressant-induced antinociceptive effect in the formalin test.

RESULTS

In the hot plate test, desipramine, 20 mg.kg(-1), but not imipramine or sertraline, produced a significant increase in reaction time. In the formalin test, desipramine and imipramine produced significant reductions in the licking time at over 5 mg.kg(-1) and at over 10 mg.kg(-1), respectively. These reductions were nearly complete at 20 mg.kg(-1). On the other hand, both SSRIs induced significant reductions in the licking time only at 20 mg.kg(-1). Prazosin, WB-4101, and ketanserin significantly antagonized the antinociceptive effect of 10 mg.kg(-1) of imipramine. However, imipramine-induced antinociception was not affected by yohimbine and WAY-100635. Prazosin and ketanserin also significantly suppressed antinociception by 5 mg.kg(-1) of desipramine.

CONCLUSION

These findings suggest that classical TCAs are likely to have a therapeutic advantage over SSRIs for pain control. In addition, it is likely that central alpha(1) adrenoceptors and 5-HT(2) receptors are predominantly involved in imipramine- and desipramine-induced antinociception.

Prognostic index of liver cirrhosis with ascites with and without hepatocellular carcinoma

BACKGROUND

In Japan, the incidence of liver cirrhosis caused by hepatitis viruses is higher, and cirrhosis is more likely to be complicated by hepatocellular carcinoma, than in Western countries. The aim of this study was to predict the outcome in liver cirrhosis with ascites with and without hepatocellular carcinoma.

METHODS

The subjects were 146 patients with liver cirrhosis complicated by ascites. Forty-six factors were evaluated concerning clinical laboratory parameters and extracted prognostic factors using the Cox proportional hazards model.

RESULTS

The mean duration of the follow-up period was 634.9 days, during which 89 (61%) of the patients died, 27 (18.5%) survived, and 30 (20.6%) were lost to follow-up. The cumulative survival rate after the onset of ascites was 59.7% after 1 year, 44.5% after 2 years, and 29.5% after 5 years. Multivariate analysis indicated 9 factors, i.e. age, total bilirubin (T-Bil), alkaline phosphatase (ALP), blood urea nitrogen (BUN), alpha-fetoprotein (AFP), mean arterial pressure (MAP), gastrointestinal bleeding, infection, and portal vein tumor thrombosis (PVTT), as independent prognostic factors. The prognostic index (PI) was calculated by the following formula using these 9 factors. PI = 0.045 x age + 0.180 x T-Bil + 0.088 x ALP + 0.020 x BUN + 0.467 x AFP + (-0.022 x MAP) + 0.662 x gastrointestinal bleeding + 0.521 x infections + 0.882 x PVTT.

CONCLUSION

Prediction of the outcome using PI based on the 9 factors provides additional information for the determination of the therapeutic approach in cirrhotic patients with ascites with and without hepatocellular carcinoma.

Induction of kf-1 after repeated electroconvulsive treatment and chronic antidepressant treatment in rat frontal cortex and hippocampus

It has been proposed that signaling pathways involved in adaptive neural plasticity are long-term targets for the action of electroconvulsive treatment (ECT), which is widely used in the treatment of drug-resistant depression. We have previously performed EST analysis to identify some molecular machinery responsible for antidepressant effect. One of the cDNA fragments identified as antidepressant related genes/ESTs was identified as kf-1 which has a RING-H2 finger motif at the carboxy-terminus. In the present study, we have demonstrated the induction of kf-1 in rat frontal cortex and hippocampus not only after chronic antidepressant treatment, but also after a single and repeated ECT. RING finger proteins are proposed to play some important roles in the ubiquitin-proteasome system. In conclusion, the current investigation has identified kf-1 as a novel molecular target for antidepressants and ECT.

Carboxy-PTIO increases the tetrahydrobiopterin level in mouse brain microvascular endothelial cells

The aim of the present study was to characterize the increase in tetrahydrobiopterin (BH4), which is a cofactor for nitric oxide synthase (NOS), by carboxy-PTIO, a scavenger of nitric oxide (NO), in vascular endothelial cells. BH4 level was determined by oxidation under acidic conditions as biopterin. Addition of lipopolysaccharide (LPS) to endothelial cells increased mRNA levels of inducible NOS (iNOS) and GTP-cyclohydrolase I (GTPCH), which is a rate-limiting enzyme for BH4 synthesis, and the biopterin level. NOS inhibitors, NO-donors and L-arginine, a substrate of NOS, did not affect the increase in the biopterin level induced by LPS, suggesting that BH4 synthesis is unlikely to be modulated by NO produced by iNOS during LPS treatment. However, carboxy-PTIO increased the biopterin level in the absence and the presence of LPS. Carboxy-PTIO did not affect the expression of GTPCH mRNA level. Moreover, 2,4-diamino-6-hydroxypyrimidine, an inhibitor of GTPCH, inhibited only about 30% of the carboxy-PTIO-induced increase in the biopterin level. Whereas, N-acetylserotonin, an inhibitor of sepiapterin reductase, strongly inhibited the increase in biopterin level. Carboxy-PTIO inhibited the accumulation of pterin, a decomposition product of BH4 in endothelial cells. These findings suggest that carboxy-PTIO accumulates BH4 under basal and LPS-treated conditions in vascular endothelial cells due to both inhibition of the decomposition of BH4 to pterin and activation of the salvage pathway of BH4 synthesis via sepiapterin reductase.

Entactin-induced inhibition of human amyloid beta-protein fibril formation in vitro

Amyloid beta-protein (Abeta) fibril in senile plaques may possibly be related to the pathogenesis of Alzheimer's disease (AD). Basement membrane (BM) components are localized to the plaques. Entactin binds the plaque associated BM components. We investigated the potential of entactin to prevent Abeta fibril formation. Thioflavin T fluorometric assay and electron microscopy revealed that entactin significantly inhibited Abeta1-40 (Abeta40) fibril formation at an Abeta40:entactin molar ratio of 50:1. The inhibitory effect of entactin was displayed in a dose-dependent manner. Circular dichroism spectroscopy data indicated that entactin induced a random coil structure in Abeta40. We propose that the ability of entactin to induce random structure is linked to the inhibition of Abeta fibril formation. Entactin may be related to the pathogenesis of AD by regulating Abeta40 fibril formation.

β-amyloid induces caspase-dependent early neurotoxic change in PC12 cells: correlation with H2O2 neurotoxicity

We examined neurotoxic effects of Abeta(25-35), an active fragment of beta-amyloid (Abeta), and compared the effect with H2O2 neurotoxicity in PC12 cells. Abeta(25-35) induced the loss of mitochondria function as detected using a tetrazolium salt (WST-1) reduction assay and decreased the number of cells adhering to collagen type 1-coated plates. Abeta(25-35) did not induce cell death, as detected by Hoechst 33342/propidium iodide staining. The caspase tetrapeptide inhibitor z-IETD-fluoromethylketone (FMK) and z-LEHD-FMK inhibited the attenuation of WST-1 reduction induced by Abeta(25-35) and H2O2, while the caspase-3 inhibitor z-DEVD-FMK afforded protection only against H2O2 neurotoxicity. Caspase-3 protease activity was increased by treatment of H2O2 but not Abeta(25-35). Thus, Abeta(25-35) induces early neurotoxic events by activating caspases other than caspase-3. H2O2 -induced oxidative stress may not be implicated in Abeta-induced neurotoxic pathways.

Regulation of serotonin transporter gene expression in human glial cells by growth factors

The aims of this study were to identify monoamine transporters expressed in human glial cells, and to examine the regulation of their expression by stress-related growth factors. The expression of serotonin transporter mRNA was detected by reverse transcriptase-polymerase chain reaction in normal human astrocytes, whereas the dopamine transporter (DAT) and the norepinephrine transporter (NET) were not detected. The cDNA sequence of the "glial" serotonin transporter in astrocytes was consistent with that reported for the "neuronal" serotonin transporter (SERT). Moreover, we also demonstrated SERT expression in glial fibrillary acidic protein-positive cells by immunocytochemical staining in normal human astrocytes. Serotonin transporter gene expression was also detected in glioma-derived cell lines (A172, KG-1-C and KGK). Addition of basic fibroblast growth factor (bFGF) or epidermal growth factor (EGF) for 2 days increased serotonin transporter gene expression in astrocytes and JAR (human choriocarcinoma cell line). Basic fibroblast growth factor, but not epidermal growth factor, increased specific [3H]serotonin uptake in astrocytes in a time (1-4 days)- and concentration (20-100 ng/ml)-dependent manner. The expression of genes for basic fibroblast growth factor and epidermal growth factor receptors was detected in astrocytes. These findings suggest that the expression of the serotonin transporter in human glial cells is positively regulated by basic fibroblast growth factor.

Induction of cysteine string protein after chronic antidepressant treatment in rat frontal cortex

We have previously identified 204 partial cDNA fragments (ADRG1-204) as antidepressant related genes/expressed sequence tags. Then, we developed our original cDNA microarrays, on which the 194 clones out of ADRG1-204 were spotted. With this ADRG microarray, we found that the expression of a spot, ADRG55, which representing cysteine string protein (CSP), was significantly increased in rat brain after chronic treatment with a selective serotonin reuptake inhibitor, sertraline. In the present study, reverse transcription-polymerase chain reaction analysis confirmed the induction of CSP at mRNA levels in rat frontal cortex after chronic treatment with two different classes of antidepressants, imipramine or sertraline. Western blot analysis also revealed that CSP-immunoreactivity was increased after antidepressant treatment. In conclusion, our data suggest that CSP is one of the common functional molecules induced after chronic antidepressant treatment.

[Effects of topical prostaglandin analogues on the aqueous flare intensity in rabbit eyes at an early phase of endotoxin-induced uveitis]

PURPOSE

We examined the effects of prostaglandin analogues on the blood-aqueous barrier(BAB) permeability in rabbit eyes at an early phase of endotoxin-induced uveitis(EIU).

SUBJECTS AND METHODS

One drop of 0.005% latanoprost or 0.12% unoprostone were applied to rabbit eyes. Escherichia coli lipopolysaccharides were injected to induce uveitis. The changes in flare intensity in normal eyes and EIU eyes after application of eye drops were evaluated. The effect of cyclooxygenase inhibitor on the flare intensity changes caused by the application of unoprostone was also examined.

RESULTS

Flare intensity increased significantly after a single instillation of unoprostone, and the increase was not prevented by pretreatment with cyclooxygenase inhibitor. In eyes with EIU, unoprostone caused an additional increase of flare intensity to uveitis induced flare change. Latanoprost had no effects on BAB in eyes with normal and with uveitic conditions.

CONCLUSION

Latanoprost and unoprostone did not cause an excessive inflammatory reaction in rabbit eyes at an early phase of EIU.

Stimulation of tetrahydrobiopterin synthesis induced by insulin: possible involvement of phosphatidylinositol 3-kinase

Although we recently showed that insulin increases the intracellular concentration of tetrahydrobiopterin (BH4), which is one of the cofactors of nitric oxide (NO) synthase, the mechanism of the effect was not elucidated. In the present study, we examined the signaling pathway of the stimulation of BH4 synthesis by insulin in mouse brain microvascular endothelial cells. Extracellular and intracellular BH4 levels were determined as biopterin by using reversed-phase high performance liquid chromatography with fluorometric detection. Measurement of the level of mRNA for GTP cyclohydrolase I (GTPCH), which is the rate-limiting enzyme for de novo BH4 synthesis, was performed by reverse transcription-polymerase chain reaction (RT-PCR). Addition of insulin to endothelial cells caused an increase of not only the intracellular but also the extracellular BH4 level in a time- and a concentration-dependent manner. Insulin also induced an increase of the level of GTPCH mRNA. Moreover, 2,4-diamino-6-hydroxypyrimidine, an inhibitor of GTPCH, inhibited the insulin-induced enhancement of BH4 synthesis. The increase in the BH4 level and the induction of GTPCH mRNA by insulin were reduced by wortmannin and LY294002, which are both phosphatidylinositol 3-kinase (PI3-kinase) inhibitors. These results suggest that insulin stimulates BH4 synthesis through the de novo synthetic pathway involving induction of GTPCH, and that the signaling pathway involves the activation of PI3-kinase.

Identification of a novel gene with RING-H2 finger motif induced after chronic antidepressant treatment in rat brain

Previously, we have identified 200 cDNA fragments as antidepressant related genes/ESTs. In this study, using these cDNAs, we developed our original cDNA microarray for rapid secondary screening of candidate genes as the novel therapeutic targets. With this microarray, we found that the expression of a novel gene, ADRG34, was significantly increased in rat hippocampus which had been chronically treated with a selective serotonin reuptake inhibitor antidepressant, sertraline. RT-PCR analysis also demonstrated the induction of ADRG34 at mRNA levels in rat hippocampus and the frontal cortex. This cDNA encoded 685 amino acid residues containing a RING-H2 finger motif at the carboxy-terminal. Sequence analysis of ADRG34 with the EMBL/GenBank database showed significant homology to mouse and human kf-1 gene. Our data suggest that ADRG34, a possible rat homologue of kf-1, may be one of the common functional molecules induced after chronic antidepressant treatment.

T lymphopenia in genetically obese-diabetic Wistar fatty rats: effects of body weight reduction on T cells

Patients with long-standing diabetes may have a propensity for infection-related mortality. In this study, lymphocyte subsets, the proliferative response of splenocytes to mitogens, and circulating levels of tumor necrosis factor alpha (TNF-alpha) in genetically obese-diabetic Wistar fatty (fa/fa) rats (WF) were longitudinally compared versus lean (+/?) litters (WL). Moreover, the effects of weight reduction with voglibose treatment on immunity were evaluated (WFV and WLV). Body weight was significantly increased in WF compared with WL. Hyperglycemia and hyperlipidemia developed, respectively, 11 weeks and 5 weeks thereafter throughout the observation periods. Circulating T cells and T-cell subsets of WF were significantly reduced after 22 weeks. There were also significant decreases in CD4+ and CD8+ thymocytes and the proliferative response of splenocytes. Circulating levels of TNF-alpha were significantly increased in WF. Treatment with voglibose resulted in significantly reduced blood glucose, insulin, cholesterol, triglyceride, and body weight in WFV. After weight reduction, circulating T cells and T-cell subsets were increased and TNF-alpha was decreased significantly in WFV. Our results suggest that the number and function of T cells in WF may be reduced, which may be related at least in part to elevated TNF-alpha levels, although the role of the other factors such as glucose, insulin, cholesterol, and triglycerides on T-cell immunity should be further investigated.

A novel effect of polymorphonuclear leukocytes in the facilitation of angiogenesis

The purpose of this study was to examine whether the adhesion of polymorphonuclear leukocytes (PMNs) to endothelial cells and/or reactive oxygen species (ROS) released from PMNs are responsible for inducing angiogenesis. Angiogenesis was assessed by tube formation using endothelial cells obtained from bovine thoracic aorta (BAECs) grown on a layer of collagen type I. Addition of PMNs to BAECs weakly induced angiogenesis. The angiogenesis induced by PMNs alone was further enhanced by treatment of the PMNs with N-formyl-methionyl-leucyl-phenylalanine (FMLP), a selective activator of PMN. The involvement of PMN adhesion to BAECs via adhesion molecules in angiogenesis was investigated by using monoclonal antibodies against E-selectin and intercellular adhesion molecule-1 (ICAM-1). These antibodies blocked both the PMN adhesion to BAECs and the enhancement of angiogenesis induced by FMLP-treated PMNs. Furthermore, the enhancement of angiogenesis by FMLP-treated PMNs was blocked by catalase, a scavenging enzyme of H2O2, but not by superoxide dismutase (SOD). These results suggest that PMNs induce angiogenesis in vitro, and that the mechanism of stimulation of angiogenesis by PMNs may involve the adherence of PMNs to endothelial cells via E-selectin and ICAM-1, and H2O2, but not superoxide. Thus, activated PMNs in pathological states may not only induce tissue injury, but may also function as regulators of angiogenesis.

Active-oxygen involvement in canine NK-mediated cytotoxicity

We examined the relationship between natural killer (NK) cell-mediated cytotoxicity, the produced active-oxygen and cytotoxic factor (CF) release in co-culturing canine NK cells with tumor cells (CL-1 target cells). In co-culturing, the adding of n-propyl gallate (active-oxide scavenger) removed the produced active-oxygen, which inhibited NK cell-mediated cytotoxicity and the CF release. Moreover, adding of this agent inhibited the tyrosine phosphorylation of NK intracellular protein which observed in co-culturing. Therefore, the active-oxygen produced from canine NK cells are thought to relate the signal transduction in NK-mediated cytotoxicity.

Identification of epidermal growth factor mRNA-expressing cells in the mouse anterior pituitary

Epidermal growth factor (EGF) produced within the pituitary gland is associated with the growth of pituitary cells in rats. The aim of the present study was to localize EGF- and EGF receptor-expressing cells, and to clarify the involvement of EGF in DNA replication in 2-month-old male mouse pituitary cells. In situ hybridization of the pituitaries of these mice demonstrated that EGF mRNA was expressed in the anterior and intermediate lobes. Within the anterior pituitary, EGF mRNA-expressing cells were medium-sized and round, and made up 40% of the total number of secretory cells. EGF receptor mRNA was only detected in anterior pituitary cells. Forty-seven percent anterior pituitary cells expressed EGF receptor mRNA. An immunocytochemical study showed that most somatotropes and some mammotropes expressed EGF mRNA. When anterior pituitary cells were enzymatically dissociated and cultured in serum-free medium, RT-PCR demonstrated both EGF mRNA and EGF receptor mRNA expression. Treatment with EGF (1 and 10 ng/ml) for 5 days stimulated DNA replication in mammotropes and corticotropes. These results indicate that the DNA replication in mammotropes and corticotropes is regulated by the paracrine and/or autocrine activity of EGF produced at least in part by these cell types themselves.

Synthesis and structure-activity relationships of a new class of selective EP3 receptor agonist, 13,14-didehydro-16-phenoxy analogues of prostaglandin E1

A series of 13,14-didehydro-16-phenoxy analogues of prostaglandin E1 was synthesized and their agonistic activity on EP receptor subtypes was evaluated. 13,14-Didehydro-16-phenoxy-1-decarboxy analogues, 7e and 7f, display highly selective activity on the EP3 receptor subtype, thus, their utility as a selective anti-ulcer agent can be expected.

Involvement of reactive oxygen species and nitric oxide in gastric ischemia-reperfusion injury in rats: protective effect of tetrahydrobiopterin

The purpose of this study was to examine whether tetrahydrobiopterin (BH4), a cofactor of nitric oxide (NO) synthase, attenuates gastric ischemia-reperfusion injury induced by clamping of the celiac artery. Gastric injury was assessed by a formation of gastric mucosal erosions. The gastric injury was observed at 30 and 60 min after reperfusion following 30-min ischemia and was reduced by superoxide dismutase (SOD), catalase, or NO synthase inhibitors. Therefore, reactive oxygen species (ROS) and NO seem to be implicated in the ischemia-reperfusion injury. Treatment with BH4 reduced the ischemia-reperfusion injury. Pretreatment with sepiapterin, a precursor of BH4, also reduced the ischemia-reperfusion injury with an increase in BH4 content in serum and stomach. Both the increase in BH4 content and the protective effect of sepiapterin were prevented of pretreatment with N-acetylserotonin, an inhibitor of BH4 synthesis. These results suggest that the increase in BH4 content may protect against gastric ischemia-reperfusion injury via reduction of ROS and/or NO toxicity. BH4 might be useful as a therapeutic agent for gastric ischemia-reperfusion injury.

[Effect of stellate ganglion block on human retinal blood flow]

PURPOSE

The effect of stellate ganglion block (SGB) on human retinal blood flow was evaluated.

METHODS

We measured the diameter of the retinal artery and vein, and retinal venous flow rate by laser speckle retinal blood flow meter simultaneously in 11 eyes of 11 normal volunteers.

RESULTS

The reliable data from 9 eyes of 9 person were used for analysis. SGB did not change the blood pressure, heart rate, retinal arterial diameter, or venous diameter. However SGB increased retinal blood velocity significantly from 9.9 +/- 1.6 (mean +/- standard deviation) mm/s to 11.1 +/- 1.5 mm/s (p < 0.01). Intraocular pressure decreased from 12.3 +/- 2.1 (mean +/- standard deviation)mmHg to 9.4 +/- 2.2 mmHg after SGB (p < 0.01). There was no relationship between the change of ocular perfusion pressure and that of retinal venous blood velocity.

CONCLUSION

SGB increased the retinal venous blood velocity without changing the retinal vessel diameter.

Protective effect of nitric oxide against iron-induced neuronal damage

We investigated the effect of nitric oxide (NO) on iron-induced neuronal damage. Incubation of PC12 cells after the addition of FeCl2 induced rapid increases (within 1 hr) in lipid peroxidation and a concentration (0.1-2 mM)-dependent decrease in cell viability at 48 hr, both of which were blocked by deferoxamine and 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazine-3-o ne hydrochloride (MCLA) (a superoxide scavenger) but not by mannitol (a hydroxyl radical scavenger). Iron-induced cytotoxicity was also antagonized by superoxide dismutase with catalase. On the other hand, the NO donors S-nitroso-N-acetylpenicillamine (SNAP), 3-¿(+/-)-(E)-ethyl-2'-[(E)-hydroxylamino]-5-nitro-3-hexenecarbo moyl¿-pyridine (NOR-4), and 2,2'-(hydroxynitrosohydrazono)bis-ethanamine (NOC-18) decreased cell viability 48 hr after addition without increasing lipid peroxidation. However, when added with 1 mM FeCl2, NO donors including NOC-18, SNAP and NOR-4 (0.1-1 mM) inhibited lipid peroxidation in a concentration-dependent manner and suppressed cell death at lower concentrations. Addition of MCLA and NOC-18 also suppressed decreases in iron-induced [3H]thymidine incorporation. In rat brain homogenate, NOC-18 and SNAP both suppressed iron-induced lipid peroxidation. These findings suggest that NO has a dual effect on neuronal viability and can act as an antioxidant which protects neurons from iron-induced damage.

Changes in mRNA levels of fibrinogen subunit polypeptides in rats defibrinogenated with batroxobin

Batroxobin is a snake venom that is a thrombinlike enzyme used for clinical treatment. We analyzed hepatic mRNA levels for fibrinogen subunit polypeptides and prothrombin by reverse transcription-polymerase chain reaction as well as coagulation and fibrinolysis factors in plasma 1, 3, 5 and 24 hours after Batroxobin treatment (3 BU/100 g) in rats. The mRNA levels of alpha- and beta-chains of fibrinogen were significantly increased with decreases in plasma fibrinogen, alpha2-plasmin inhibitor, and plasminogen levels, while the mRNA levels for prothrombin remained unchanged. These results suggest that fibrinogen mRNA synthesis is regulated by plasma fibrinogen levels in Batroxobin-induced defibrinogenated rats.

Regulation of dopamine uptake by basic fibroblast growth factor and epidermal growth factor in cultured rat astrocytes

We examined the characteristics of dopamine (DA) uptake and its regulation by neurotrophic factors such as basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) in cultured rat astrocytes. In the presence of inhibitors of monoamine oxidase (MAO) and catechol-O-methyl-transferase (COMT), astrocytes took up DA by Na(+)-dependent and Na(+)-independent mechanisms that were sensitive to a reduction in temperature. The Na(+)-dependent and Na(+)-independent components increased linearly with increasing [3H]DA concentration (1-1000 microM), and showed no saturation. Na(+)-dependent DA uptake was significantly inhibited by ouabain, a Na(+)-K+ ATPase inhibitor. In bFGF-treated astrocytes, [3H]DA uptake increased in a time-dependent manner until 48 h, and declined after 72 h in both the presence and absence of Na+. In EGF-treated astrocytes, [3H]DA uptake increased in a time-dependent manner until 72 h in both the presence and absence of Na +. This enhancement of DA uptake induced by EGF or bFGF was significantly inhibited when the cells were cultured with actinomycin D, cycloheximide, or brefeldin A. Actinomycin D and brefeldin A also significantly inhibited the basal uptake of [3H]DA into astrocytes. These results suggest the existence of Na(+)-dependent and Na(+)-independent DA uptake in cultured rat astrocytes, and that EGF or bFGF might stimulate the expression and translocation of the extraneuronal DA transporter.

Identification of a novel splice variant of heat shock cognate protein 70 after chronic antidepressant treatment in rat frontal cortex

In this study, we identified a novel splice variant of 70-kDa heat shock cognate protein (HSC70), while screening differentially expressed molecules in rat brain after chronic antidepressant treatment. This clone, named HSC49, lacked 470 bp of nucleotides of rat HSC70. HSC49 encoded 442 amino acid residues with a calculated molecular mass of 48.6 kDa. DNA sequence analysis revealed that HSC49 lacked the entire Exon 7 and Exon 8 of the HSC70 gene. Chronic treatment with antidepressant, imipramine or sertraline, induced a 38.5 or 22.5% increase in mRNA levels in rat frontal cortex, respectively, when compared to controls. Western blot analysis also revealed that the protein expression of HSC49 was increased after antidepressant treatment. Our data suggest that HSC49 may be one of the common molecules induced after chronic antidepressant treatment.

Morphological observation of canine natural killer cells mediated cytotoxicity

The cytotoxic effects of canine NK cells on CL-1 target cells were examined by scanning electron microscopy (SEM). NK cell mediated cytotoxicity on CL-1 target cells was detected by 51Cr release assay. SEM showed that a canine NK cell extended projections to the CL-1 target cell. Furthermore, the surface of CL-1 target cells changed a mesh-like structure. Therefore, the cytotoxic effects of canine NK cells on CL-1 target cells were morphologically demonstrated.

Pharmacological characterization of dopamine transport in cultured rat astrocytes

The effects of GBR-12909 (selective DA uptake inhibitor), zimelidine (selective 5-HT uptake inhibitor) and nisoxetine (selective NE uptake inhibitor) on the uptake of 30 nM [3H]DA into cultured rat astrocytes were examined. [3H]DA uptake was inhibited by approximately 50% by GBR-12909 or zimelidine in a concentration-dependent manner (100 nM to approximately 10 microM). Furthermore, the inhibition curves of GBR-12909 were biphasic, and uptake was completely inhibited by a high concentration of GBR-12909 (100 microM). [3H]DA uptake was also inhibited by approximately 50% by nisoxetine in a concentration-dependent manner (0.1 to approximately 100 nM), and nisoxetine was more potent than GBR-12909 or zimelidine. The inhibitory potencies were in the order nisoxetine > GBR-12909 > zimelidine. The uptake of [3H]DA under Na+-free conditions was approximately 50% of that under normal conditions. Thus, DA was taken up by both Na+-dependent and Na+-independent mechanisms. Nisoxetine (100 nM), zimelidine (100 microM) and GBR-12909 (10 microM) inhibited [3H]DA uptake into astrocytes only in the presence of Na+. On the other hand, this uptake was completely inhibited by a high concentration of GBR-12909 (100 microM) in the absence of Na+. The present data suggest that the Na+-dependent uptake of [3H]DA in cultured rat astrocytes may occur in the NE uptake system. Furthermore, astrocytes express the extraneuronal monoamine transporter (uptake2), which is an Na+-independent system, and this transporter is involved in the inactivation of centrally released DA.

Stimulation of in vitro angiogenesis by tetrahydrobiopterin in bovine aortic endothelial cells

This study examined whether tetrahydrobiopterin (BH4) stimulates angiogenesis by measuring the formation of tube-like structures in vascular endothelial cells. Bovine aortic endothelial cells that were cultured between two layers of collagen type I gel formed tube-like networks. Addition of BH4 or sepiapterin, a precursor of BH4 synthesis, stimulated the formation of tube-like structures. The sepiapterin-stimulated tube formation was completely inhibited by co-treatment with N-acetylserotonin, an inhibitor of sepiapterin reductase. These findings show that BH4 stimulates in vitro angiogenesis in vascular endothelial cells.

Interaction of the new histamine H2-receptor antagonist pibutidine hydrochloride with canine cloned H2-receptor expressed cells

The effect of a new histamine H2-receptor antagonist, pibutidine hydrochloride ((Z)-3-amino-4-{4-{4-[(piperidinomethyl)pyrid-2-yl]oxy} but-2-enylamino}cyclobut-3-ene-1,2-dione monohydrochloride, CAS 126463-66-9, IT-066 displaced the binding of [3H]tiotidine to cells transfected with the wild-type H2-receptor in a concentration-dependent manner. Compared with the 50% inhibitory concentration values (IC50) among five H2-receptor antagonists tested, the value of IT-066 was lowest. The inhibitory effect of IT-066 was enhanced by preincubation of IT-066 with the cells, and preincubation for 60 min increased potency about 2-fold. Famotidine also has such effects. When H2-receptor transfected cells were treated with IT-066 for 30 min, the inhibitory effect of IT-066 on the [3H]tiotidine binding still remained even after the cells were extensively washed. Scatchard plot analysis supported the non-competitive and irreversible action of IT-066. When the canine mutated H2-receptor-expressed cells were used, which have substituted amino acid of 190Alanine (Ala; position: 190th amino acid) for 190Threonine (Thr) in the fifth transmembrane domain, IT-066 also inhibited [3H]tiotidine binding to the cells concentration-dependently. However, in the case of the 190Ala mutated cells, the inhibitory effect of IT-066 attenuated with a decrease in maximal response after washing of the cells. These results show that IT-066 could tightly bind H2-receptor in a time-dependent manner and suggest the possibility that the irreversible inhibition of IT-066 is important in the interaction with 190Thr in the fifth transmembrane domain of H2-receptor.

Presence of excess tetrahydrobiopterin during nitric oxide production from inducible nitric oxide synthase in LPS-treated rat aorta

Tetrahydrobiopterin (BH4) is one of the cofactors of nitric oxide synthase (NOS), and the synthesis of BH4 is induced as well as inducible NOS (iNOS) by lipopolysaccharide (LPS) and/or cytokines. BH4 has a protective effect against the cytotoxicity induced by nitric oxide (NO) and/or reactive oxygen species in various types of cells. The purpose of this study was to examine whether or not an excess of BH4 is present during the production of NO by iNOS in LPS-treated de-endothelialized rat aorta. Addition of LPS (10 microg/ml) to the aorta bath solution caused L-arginine (L-Arg)-induced relaxation from 1.5 hr after the addition of LPS in de-endothelialized rat aorta pre-contracted with 30 mM KCl. The L-Arg-induced relaxation was prevented by NOS inhibitors. BH4 content also increased from 3 hr after the addition of LPS. mRNAs of iNOS and GTP cyclohydrolase I (GTPCH), a rate-limiting enzyme of BH4 synthesis, were increased from 1.5 hr after addition of LPS. Although the expression of iNOS and GTPCH mRNAs was observed in the media, the expression levels in the media were much lower than those in the adventitia. Ten millimolar 2,4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of GTPCH, strongly reduced L-Arg-induced relaxation, and decreased BH4 content to below the basal level in LPS-treated aorta, whereas 0.5 mM DAHP reduced the LPS-induced increase in BH4 content to the basal level but did not affect L-Arg-induced relaxation. The inhibition of L-Arg-induced relaxation by 10 mM DAHP was overcome by the addition of BH4 (10 microM). These results suggest that although BH4 is essential for NO production from iNOS, the increase in BH4 content above the basal level is not needed for eliciting L-Arg-induced relaxation by the treatment with LPS. Thus, an excess amount of BH4 may be synthesized during NO production by iNOS in LPS-treated rat aorta.

Ca(2+)-dependent enhancement of [3H]noradrenaline uptake in PC12 cells through calmodulin-dependent kinases

Ca(2+)-dependent regulation of [3H]noradrenaline ([3H]NA) uptake through the NA transporter was studied using PC12 cells. Preincubation for 10 min in the presence of 0.3-10 mM ca2+ in Krebs-Ringer (KR) buffer induced marked enhancement of the uptake (at 1 mM Ca2+, 6.6 times greater than that observed in the absence of Ca2+), which reflected both an increase in Vmax and a decrease in K(m) of the uptake process. Preincubation with 1 mM Ca2+ also induced a significant increase in the Bmax and Kd of [3H]desipramine binding. The uptake was still enhanced after washing cells with Ca(2+)-free buffer following preincubation with 1 mM Ca2+. 1-[N, O-bis(5-Isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN-62), 2-[N-(2-hydroxyethyl)-N-(4-methoxybenzenesulfonyl)]amino-N-(4-c hlo rocinnamyl) -N-methylbenzylamine (KN-93) (inhibitors of Ca2+/calmodulin-dependent kinase II), N-(6-aminohexyl)-5-chloro-1-naphthalenesulonamide (W-7) (a calmodulin antagonist), wortmannin (a myosin light chain kinase inhibitor) significantly reduced Ca(2+)-dependent enhancement of the uptake. Mycalolide B (an inhibitor of actin-myosin interaction) also inhibited the enhancement. Although calphostin C (a protein kinase C (PKC) inhibitor) did not affect the enhancement, 12-o-tetradecanoylphorbol 13-acetate (TPA) inhibited the uptake. A synthetic peptide with a sequence (KKVIYKFFS579 IRGSLW) contained in the intracellular COOH-terminal domain of a rat NA transporter was phosphorylated by purified brain Ca2+/calmodulin-dependent protein kinase II. These results suggest that Ca(2+)-dependent enhancement of the [3H]NA uptake in PC12 cells are mediated by activation of calmodulin-dependent protein kinases, probably through stimulation of translocation of the NA transporter to the plasma membrane and/or direct phosphorylation of the transporter itself.

cDNA cloning and inducible expression of human multidrug resistance associated protein 3 (MRP3)

Previously, we cloned rat MRP3 as a candidate for an inducible transporter for the biliary excretion of organic anions [Hirohashi et al. (1998) Mol. Pharmacol. 53, 1068-10751. In the present study, we cloned human MRP3 (1527 amino acids) from Caco-2 cells. Human MRP3 is predominantly expressed in liver, small intestine and colon; hepatic expression of MRP3 was observed in humans but not in normal rats. In HepG2 cells, the expression of MRP3 was induced by phenobarbital. These results suggest that MRP3 may act as an inducible transporter in the biliary and intestinal excretion of organic anions.

Role of nitric oxide and prostaglandin in the protective effect of pibutidine hydrochloride, a novel histamine H2-receptor antagonist, on the gastric mucosal lesions in rats

1. The role of endogenous nitric oxide (NO) and prostaglandins (PGs) in the gastric mucosal protective action of pibutidine hydrochloride (IT-066), a novel histamine H2-receptor antagonist, was investigated in a 0.15 N hydrochloride (HCl) + 60% ethanol (EtOH)-induced gastric lesion model. 2. The 0.15 N HCl + 60% EtOH-induced lesion formation was reduced significantly by IT-066 (3 mg/kg, PO), NOR3 (spontaneous NO releaser; 0.03-0.1 mg/kg, SC) or PGE2 (0.01 mg/kg, PO) but was not reduced by famotidine (1-10 mg/kg, PO). 3. Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME) (3 mg/kg, IV), an inhibitor of NO synthase, inhibited the protective action of IT-066 (3 mg/kg, PO), and the inhibitory effect of L-NAME was reversed by L-arginine (300 mg/kg, IV). The protective effect of PGE2 (0.01 mg/kg, PO) was not affected by the pretreatment with L-NAME (3 mg/kg, IV). 4. Infusion of carboxy-PTIO (1 mg/kg/min), a direct NO scavenger, inhibited the protective effect of IT-066 (3 mg/kg, SC) or NOR3 (0.1 mg/kg, SC). Pretreatment with indomethacin (5 mg/kg, SC) markedly reduced the protective effect of IT-066 (3 mg/kg, PO) or NOR3 (0.1 mg/kg, SC). 5. These results suggest that endogenous NO and PGs may be implicated in the gastric mucosal protection induced by IT-066 and that the endogenous PGs may contribute to the protective effect of NO.

Dehydroepiandrosterone decreases serum tumor necrosis factor-alpha and restores insulin sensitivity: independent effect from secondary weight reduction in genetically obese Zucker fatty rats

Dehydroepiandrosterone (DHEA) and its sulfate ester are the most abundant circulating adrenal steroids in humans. Administration of DHEA has been reported to have beneficial effects on obesity, hyperlipidemia, diabetes, and atherosclerosis in obese rodents, although its effects on insulin resistance have not been fully elucidated. In this study, the effects of DHEA treatment on insulin sensitivity were investigated in genetically obese Zucker rats, an animal model of insulin resistance, using the euglycemic clamp technique. After 0.4% DHEA was administered for 10 days to female obese Zucker rats aged 16 weeks, body weight and plasma insulin decreased and glucose disposal rate (GDR), which was normally reduced in obese rats, rose significantly compared with age- and sex-matched control obese rats. On the other hand, although the pair-fed obese rats also showed levels of weight reduction similar to those of DHEA-treated rats, the increase in GDR of DHEA-treated rats was significantly greater than in pair-fed rats, suggesting a direct ameliorating effect of DHEA on insulin sensitivity of obese rats. Serum concentration of tumor necrosis factor (TNF)-alpha, one of cytokines causing insulin resistance, was also reduced significantly in DHEA-treated, but not in pair-fed obese rats. In conclusion, our results suggest that DHEA treatment reduces body weight and serum TNF-alpha independently, and that both may ameliorate insulin resistance in obese Zucker fatty rats.

Effect of pibutidine hydrochloride on nitric oxide production in rat gastric mucosa

This study examined the effect of pibutidine hydrochloride, a novel histamine H2 receptor antagonist (IT-066), on nitric oxide (NO) production in gastric mucosa by measuring nitrite and nitrate contents. IT-066 (0.3-3 mg/kg, p.o.) and NO donors, sodium nitroprusside (0.3 mg/kg, s.c.) and NOR3 (0.1 mg/kg, s.c.), increased the NO contents in gastric mucosa. Cimetidine (100 mg/kg, p.o.), ranitidine (30 mg/kg, p.o.) and famotidine (10 mg/kg, p.o.) did not significantly affect the NO production. Pretreatment with NG-nitro-L-arginine methyl ester (3 mg/kg, i.v.), a NO synthase inhibitor, decreased the level of IT-066 (3 mg/kg, p.o.)-stimulated NO production. These results suggest that IT-066 stimulated gastric mucosal NO production, and that endogenous NO may be implicated in the pharmacological effect of IT-066.