Immune complexome analysis of a rich variety of serum immune complexes identifies disease-characteristic immune complex antigens in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular endothelial dysfunction and skin fibrosis. Recently, the presence and pathogenic role of immune complexes (ICs) of SSc patients were reported. However, the identities of antigens in these ICs are unknown. Therefore, we examined ICs in the serum of SSc patients to elucidate SSc pathogenesis. In this study, IC concentrations in serum samples from SSc and systemic lupus erythematosus (SLE) patients were measured by C1q enzyme-linked immunosorbent assays; immune complex analysis was used for comprehensive identification and comparison of antigens incorporated into ICs (IC-antigens). The expression patterns of SSc-specific IC-antigens in skin sections were investigated by immunohistochemistry. Compared with SLE patients who developed disease because of IC deposition, SSc patients had a greater number of IC-antigens and a smaller difference in IC concentrations, suggesting that SSc pathogenesis is affected by the proteins present in ICs. In contrast, the IC concentration and number of IC-antigens did not significantly differ according to the clinical phenotype of SSc. We identified 478 IC-antigens in SSc patients, including multiple RNAP II-associated proteins that were targeted by antibodies previously associated with SSc pathogenesis. The most frequently detected RNAP II-associated protein, RNA polymerase II transcription subunit 30 (MED30), was strongly expressed at lesion sites and reportedly regulates endothelial differentiation. Therefore, increased expression of MED30 in lesions may have an antigenic effect, and MED30 function may be impaired or inhibited by IC formation. RNAP II-associated proteins may SSc pathogenesis through mechanisms such as the MED30 pathway.

Survey of prescriptions for triple whammy drug combinations with vitamin D as a possible fourth whammy.

BACKGROUND: Improper prescriptions can cause adverse reactions in patients with chronic kidney disease (CKD). MATERIALS AND METHODS: Hospital pharmacists investigated improper prescriptions, prerenal acute kidney injury (AKI) prescriptions, and adverse effects in AKI in 199 CKD patients at Kouseikai Hospital from July 2020 to June 2021, as well as combinations of "triple whammy" drugs (renin-angiotensin-system inhibitors, diuretics, and non-steroidal anti-inflammatory drugs) plus active vitamin D preparations. All participants (average age, 73.6 ± 16.2 years) were residents of Nagasaki City or its suburbs. RESULTS: Adverse reactions occurred in 38 of the 199 patients (19.1%). 13 patients had AKI, and 9 of these cases developed during the summer. A comparison of the 38 patients in the adverse reaction group and the 161 patients in the non-occurrence group showed that the former group was significantly older and had a lower body weight. In terms of renal function, estimated glomerular filtration rate (mL/min/1.73m2) was significantly lower, blood urea nitrogen/serum creatinine (BUN/S-Cr) was higher, dehydration was involved, and active vitamin D preparations were significantly more common in the adverse reaction group. CONCLUSION: Our findings suggest that concomitant prescription of active vitamin D in combination with the drugs that constitute the triple whammy should be avoided. The absence of hypercalcemia should be confirmed and adequate fluid intake should be encouraged to prevent prerenal nephropathy.

Combination index of the concentration and in vivo antagonism activity of racemic warfarin and its metabolites to assess individual drug responses.

The present study was undertaken to examine whether in vivo vitamin K epoxide reductase complex 1 (VKOR) "actual" antagonism activity, calculated by the concentrations and the reported anticoagulant activities of the R- and S-warfarin enantiomers and their metabolites, correlates with the weekly dose of warfarin. Five patients under palliative care were enrolled in our study and 20 serum samples were analyzed by an enantioselective high-performance liquid chromatography-ultraviolet detection method. In vivo VKOR inhibition activities of S-warfarin, R-warfarin, 7- and 10-hydroxywarfarin were calculated as the ratio of drug or metabolite concentration to the IC50. The mean drug concentrations (± SD) of S- and R-warfarin, 7-hydroxywarfarin and 10-hydroxywarfarin were 334 ± 154 ng/ml, 370 ± 115 ng/ml, 42 ± 15 ng/ml and 80 ± 44 ng/ml, respectively. Then, in vivo VKOR actual antagonism activities of S- and R-warfarin, 7-hydroxywarfarin and 10-hydroxywarfarin were calculated. Good correlation (R2 = 0.69-0.72) was obtained between the weekly warfarin dose and the ratios of INR/actual antagonism activity, while poor correlation was observed between the weekly warfarin dose and INR (R2 = 0.32) or the activities (R2 = 0.17-0.21). Actual antagonism activities along with the INR correlated well with the warfarin dose. This parameter may be useful for predicting or altering warfarin doses, although further verification in a larger study is required.

Relationship Between Constipation and Medication.

Constipation is very common and can be caused by adverse drug reactions as a result of many drugs. While the adverse effects of several medications such as opioids and anticholinergic agents are well established and well known, other commonly prescribed drugs, such as hypnotics, are less well understood. This review presents the results of an analysis of the relationship between constipation and drugs.

Evaluation for Peritoneal Injury at an Early Stage Using Dual Macromolecular Markers.

Long-term peritoneal dialysis (PD) frequently produces morphological and functional changes of the peritoneum, making continuation of PD difficult. Therefore, it is necessary to evaluate peritoneal injury at an early stage and develop appropriate therapies. The aims of the present study were to evaluate peritoneal injury at an early stage and assess a drug for prevention of peritoneal injury using our previously developed novel evaluation method. Peritoneal injury was induced in model animals by intraperitoneal injection of methylglyoxal (MGO) for 1 to 5 consecutive days or chlorhexidine digluconate (CG) for 1 to 14 consecutive days. Tetramethylrhodamine-dextran (RD)-10 and fluorescein isothiocyanate-dextran (FD)-2000 were then injected into the peritoneal cavity and recovered after 120 min to evaluate peritoneal injury. The ratio of the concentration of RD-10 to FD-2000 (RD-10/FD-2000 ratio) significantly decreased in animals that had been treated with MGO or CG for 1 d. Moreover, the RD-10/FD-2000 ratio significantly increased in CG- and thalidomide-treated animals. The RD-10/FD-2000 ratio can be used to evaluate peritoneal injury at an early stage and assess the drug efficacy of thalidomide for prevention of peritoneal injury. This study will contribute to the development of therapeutic treatments for peritoneal injury.

Evaluation of hypothermia on the in vitro metabolism and binding and in vivo disposition of midazolam in rats.

The effect of hypothermia on the in vivo pharmacokinetics of midazolam was evaluated, with a focus on altered metabolism in the liver and binding to serum proteins. Rat primary hepatocytes were incubated with midazolam (which is metabolized mainly by CYP3A2) at 37, 32 or 28 °C. The Michaelis-Menten constant (Km) and maximum velocity (Vmax) of midazolam were estimated using the Michaelis-Menten equation. The Km of CYP3A2 midazolam remained unchanged, but the Vmax decreased at 28 °C. In rats, whose temperature was maintained at 37, 32 or 28 °C by a heat lamp or ice pack, the plasma concentrations of midazolam were higher, whereas those in the brain and liver were unchanged at 28 °C. The tissue/plasma concentration ratios were, however, increased significantly. The unbound fraction of midazolam in serum at 28 °C was half that at 37 °C. These pharmacokinetic changes associated with hypothermic conditions were due to reductions in CYP3A2 activity and protein binding.

Novel diagnostic method of peritoneal injury using dual macromolecular markers.

Long-term peritoneal dialysis (PD) frequently produces morphological and functional changes of the peritoneum, which makes continuation of PD difficult. Moreover, the progression of peritoneal injury causes complications and poor prognosis. Since therapeutic treatments for peritoneal injury during PD have yet to be established, it is important to diagnose peritoneal injury as early as possible. The aim of this study was to develop a method of monitoring peritoneal function to diagnose peritoneal injury. Model rats of peritoneal injury were prepared by intraperitoneal injection of methylglyoxal (MGO) for five consecutive days. Then, marker substances of various molecular weights (phenolsulfonphthalein, fluorescein isothiocyanate-dextran (FD)-10, FD-40, FD-70, FD-2000 or tetramethylrhodamine-dextran (RD)-10) were injected into the peritoneal cavity. At 120 min after injection, the remaining amounts of all marker substances were significantly decreased in the MGO-treated rats compared with those in the vehicle-treated rats. Molecular weight dependence of the peritoneal permeability was observed. A substance with a molecular weight of approximately 10000 was found to be suitable to diagnose peritoneal injury. Moreover, coadministration of RD-10 with FD-2000 enabled us to monitor enhanced peritoneal permeability and the transfer of water simultaneously, without the recovery of whole PD fluid, even in the case of different ultrafiltration volumes. We demonstrated the usefulness of administering substances to evaluate peritoneal permeability and the transfer of water simultaneously to diagnose peritoneal injury. This study should be valuable for safe and effective PD.

Effect of a novel siRNA delivery system, siRNA ternary complex, on melanoma lung metastasis.

In this study, we determined effects of an anionic siRNA delivery vector, siRNA ternary complex, which is constructed with biodegradable dendrigraft poly-L-lysine (DGL) and γ-polyglutamic acid (γ-PGA) on the melanoma cells and melanoma lung metastasis. The siRNA ternary complex showed high cellular uptake and silencing effect in melanoma cell line B16-F10/Luc cells. After intravenous administration of the siRNA ternary complex, high silencing effect was also observed in the lung of B16-F10/Luc melanoma metastasis model mice. Therefore, we applied vascular endothelial growth factor (VEGF)-siRNA on the siRNA ternary complex and determined the effect on the melanoma lung metastasis. The siRNA ternary complex containing VEGF-siRNA reduced VEGF protein levels significantly in in vitro and in vivo, and the complex successfully inhibited melanoma lung metastasis. This biodegradable and effective siRNA delivery vector, siRNA ternary complex, could be available for clinical trials.

The role of fibronectin in pulmonary gene transfer following intravenous administration of lipoplex in mice.

We analyzed the effect of serum and fibronectin on pulmonary transgene expression after intravenous injection of cationic liposome-plasmid DNA (pDNA) complex (lipoplex) in mice. 1,2-Dioleoyl-3-trimethylammonium-propane (DOTAP) methyl sulfate salt/cholesterol lipoplex was incubated with several serum components for 5 min at 37°C prior to injection. We analyzed pulmonary transgene expression and pulmonary accumulation of lipoplex. While interaction with serum did not decrease pulmonary transgene expression, interaction with heat-inactivated serum did decrease it. Moreover, interaction with fibronectin enhanced pulmonary transgene expression. Inhibition of the binding of fibronectin to integrin decreased pulmonary transgene expression after injection of untreated lipoplex. We found that pulmonary accumulation of lipoplex changed depending on the kind of interacting serum components after injection. Furthermore, interaction with fibronectin increased pulmonary accumulation of lipoplex. Interaction with serum was required for pulmonary gene transfer following intravenous injection of lipoplex. Fibronectin appears to be a particularly critical component. Furthermore, the binding of fibronectin interacting with lipoplex to integrin was an important mechanism for pulmonary transgene expression.

Letrozole ameliorates liver fibrosis through the inhibition of the CTGF pathway and 17ß-hydroxysteroid dehydrogenase 13 expression.

BACKGROUND: To establish a treatment option for liver fibrosis, the possibility of the drug repurposing theory was investigated, with a focus on the off-target effects of active pharmaceutical ingredients. METHODS: First, several active pharmaceutical ingredients were screened for their effects on the gene expression in the hepatocytes using chimeric mice with humanized hepatocytes. As per the gene expression-based screening assay for 36 medications, we assessed the mechanism of the antifibrotic effect of letrozole, a third-generation aromatase inhibitor, in mouse models of liver fibrosis induced by carbon tetrachloride (CCl4) and a methionine choline-deficient (MCD) diet. We assessed liver histology, serum biochemical markers, and fibrosis-related gene and protein expressions in the hepatocytes. RESULTS: A gene expression-based screening assay revealed that letrozole had a modifying effect on fibrosis-related gene expression in the hepatocytes, including YAP, CTGF, TGF-ß, and CYP26A1. Letrozole was administered to mouse models of CCl4- and MCD-induced liver fibrosis and it ameliorated the liver fibrosis. The mechanisms involved the inhibition of the Yap-Ctgf profibrotic pathway following a decrease in retinoic acid levels in the hepatocytes caused by suppression of the hepatic retinol dehydrogenase, Hsd17b13 and activation of the retinoic acid hydrogenase, Cyp26a1. CONCLUSIONS: Letrozole slowed the progression of liver fibrosis by inhibiting the Yap-Ctgf pathway. The mechanisms involved the modification of the Hsd17b13 and Cyp26a1 expressions led to the suppression of retinoic acid in the hepatocytes, which contributed to the activation of Yap-Ctgf pathway. Because of its off-target effect, letrozole could be repurposed for the treatment of liver fibrosis. The third-generation aromatase inhibitor letrozole ameliorated liver fibrosis by suppressing the Yap-Ctgf pathway by partially modifying the Hsd17b13 and Cyp26a1 expressions, which reduced the retinoic acid level in the hepatocytes. The gene expression analysis using chimeric mice with humanized liver revealed that the mechanisms are letrozole specific and, therefore, may be repurposed for the treatment of liver fibrosis.

Immune complexome analysis of serum samples from non-small-cell lung cancer patients identifies predictive biomarkers for nivolumab therapy.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have achieved important outcomes in cancer treatment. However, current clinical biomarker tests are not suitable for some patients because they require tumor tissues and have poor predictive value for treatment responses. Therefore, the identification of biomarkers that enable screening tests in all patients is necessary. METHODS: We performed an immune complexome analysis of non-small cell lung cancer patients treated with nivolumab to comprehensively identify and compare antigens incorporated into immune complexes (IC-antigens) in serum samples from the responders (n = 15) and non-responders (n = 20). Additionally, combinations of IC-antigens characteristic to the responder group were evaluated by logistic regression analysis and receiver operating characteristics curves to examine their predictiveness for ICI treatment responses. RESULTS: The combination of predictive biomarkers detected before treatment was profilin-1, purine nucleoside phosphorylase, alpha-enolase, and nucleoside diphosphate kinase A [p = 0.0043, odds ratio = 2.26, 95% confidence interval (CI) = 1.19-4.28, area under the curve = 0.76]. The combination of predictive biomarkers detected after treatment was peptidyl-prolyl cis-trans isomerase A, ubiquitin-like modifier-activating enzyme 1, complement component C8 beta chain, and apolipoprotein L1 (p = 0.0039, odds ratio = 2.56, 95% CI = 1.25-5.23, area under the curve = 0.77). CONCLUSION: Combinations of serum IC-antigens may predict the therapeutic effect of nivolumab in non-small cell lung cancer patients.

Population pharmacokinetic investigation for optimization of amiodarone therapy in Japanese patients.

BACKGROUND: Optimal use of amiodarone (AMD) requires information regarding the drug's pharmacokinetics and the influence of various factors on the drug's disposition. This study was conducted to establish the role of patient characteristic in estimating doses of AMD using nonlinear mixed effects modeling in Japanese patients treated with oral therapy. METHODS: Serum concentrations of AMD were determined by high-performance liquid chromatography. The 151 serum trough concentrations from 23 patients receiving repetitive oral AMD were collected. Analysis of the pharmacokinetics of AMD was accomplished using a 1-compartment open pharmacokinetic model. The effect of a variety of developmental and demographic factors on AMD disposition was investigated. RESULTS: Estimates generated by nonlinear mixed effects modeling indicated that the clearance of AMD was influenced by the demographic variables: total body weight (TBW), daily dosage of AMD (DD), body mass index (BMI), gender (GEN), duration of AMD dosing (DUR), and patient clearance factor (Conc(θ); Conc = serum trough concentration of AMD). The final pharmacokinetic parameters were CL/F (L/h) = 0.072·TBW·Conc(-1.01)·1.95(DD≥200)·0.931(BMI≥25)·1.37(GEN)·DUR(-0.016), and Vd/F (L) = 78.4·TBW, where CL is total body clearance and Vd is volume of distribution. As all doses were given orally, it was impossible to assess the bioavailability (F). DD ≧200 is an indicator variable that has a value of 1 if the patient is receiving more than 200 mg daily dosage of AMD, and 0 otherwise. BMI ≧25 is an indicator variable that has a value of 1 if the BMI is 25 kg/m² and over, and 0 otherwise. GEN is an indicator variable that has a value of 1 if the patient is woman, and 0 otherwise. CONCLUSIONS: The authors developed new population pharmacokinetic parameters. Clinical application of the findings in the present study to patient care may permit selection of an appropriate initial maintenance dose, thus enabling the clinician to achieve a desired therapeutic effect.

Rubbing gastric serosal surface enhances naked plasmid DNA transfer in rats and mice.

We have developed in vivo gene transfer to mesothelial cells on the peritoneal organs, including the stomach. Simple instillation of naked plasmid DNA onto the gastric serosal surface in mice resulted in effective but transient transgene expression. Here, we developed a simple method to improve not only the transfection efficiency but also the duration of transgene expression. Rubbing the gastric serosal surface using a medical spoon immediately after instillation of naked plasmid DNA onto the gastric serosal surface resulted in 59-fold higher transgene expression 24 h after administration in rats. Without rubbing, transgene expression decreased under the detection limit 7 d after administration. On the other hand, rubbing the gastric serosal surface with a medical spoon after instillation of plasmid DNA prolonged transgene expression for one month. Mechanistic study in mice revealed that improved transfection should not be due to stimulation of cell function such as macropinocytosis by rubbing because rubbing before instillation of plasmid DNA did not improve transfection. Plasmid DNA should enter effectively into cells during rubbing. These findings are valuable to develop an effective method of in vivo gene transfer into peritoneal organs.

Case-controlled study on risk factors for the development of constipation in hospitalized patients.

Constipation is a common problem in hospitalized patients; however, the relative risks of its development with various factors have not been clarified. To clarify the risk factors associated with constipation, we performed a case-controlled study of 165 hospitalized patients who were not laxative users on admission. They were divided into case (n=35) and control (n=130) groups according to laxative administration during hospitalization. Comparison of the patient backgrounds in the two groups revealed significant differences in the activities of daily living, length of fasting, rest level on admission, cerebrovascular disease, and administration of hypnotics. Multiple logistic regression analysis using these five factors as autonomous variables showed that administration of hypnotics (odds ratio, 2.79; 95% confidence interval, 1.10-7.06; p=0.031) was significantly related to laxative use. Therefore, the administration of hypnotics may be the principal cause of constipation development in hospitalized patients and they should be used with caution.

Induction of mucosal immunity by pulmonary administration of a cell-targeting nanoparticle.

We previously found that a nanoparticle constructed with an antigen, benzalkonium chloride (BK) and γ-polyglutamic acid (γ-PGA) showed high Th1 and Th2-type immune induction after subcutaneous administration. For prophylaxis of respiratory infections, however, mucosal immunity should be induced. In this study, we investigated the effect of pulmonary administration of a nanoparticle comprising ovalbumin (OVA) as a model antigen, BK, and γ-PGA on induction of mucosal immunity in the lungs and serum. The complex was strongly taken up by RAW264.7 and DC2.4cells. After pulmonary administration, lung retention was longer for the OVA/BK/γ-PGA complex than for OVA alone. OVA-specific serum immunoglobulin (Ig)G was highly induced by the complex. High IgG and IgA levels were also induced in the bronchoalveolar lavage fluid, and in vivo toxicities were not observed. In conclusion, we effectively and safely induced mucosal immunity by pulmonary administration of an OVA/BK/γ-PGA complex.

The feasibility and safety in using acetaminophen with fentanyl for pain control after liver resection with regards to liver function: A prospective single-center pilot study in Japan.

INTRODUCTION: Acetaminophen has been widely used as an analgesic agent after various types of surgery. However, acetaminophen may sometimes induce severe liver dysfunction, which can occasionally lead to the need for liver transplantation. The aim of this study was to assess the feasibility and efficacy of administering acetaminophen to patients after liver resection (LR). PATIENTS AND METHODS: The prospective study included 50 patients who underwent the following procedures: partial LR (n = 21) and more than one section LR (n = 29). Pain control was provided with continuous intravenous fentanyl and acetaminophen every 6 hours (within 2 days). We analyzed the liver function and blood concentration of acetaminophen at 1 and 3 days after LR using high performance liquid chromatography (HPLC), and investigated the results of partial and more than one section LR, and also examined the degree of liver fibrosis. RESULTS: The alanine transaminase level on postoperative days 1, 5, and 7 and total bilirubin on postoperative days 1 to 5 after LR in patients with more than one section LR was significantly higher than the levels in patients with partial resection. No patients developed liver failure. The blood concentration of acetaminophen by HPLC was significantly elevated in patients with resection of more than one section in comparison to the partial resection group. CONCLUSION: The safety of acetaminophen was evaluated in Japanese patients who underwent different types of LR with different degrees of liver fibrosis.

Evaluation of transgene expression characteristics and DNA vaccination against melanoma metastasis of an intravenously injected ternary complex with biodegradable dendrigraft poly-L-lysine in mice.

We developed a biocompatible splenic vector for a DNA vaccine against melanoma. The splenic vector is a ternary complex composed of plasmid DNA (pDNA), biodegradable dendrigraft poly-L-lysine (DGL), and γ-polyglutamic acid (γ-PGA), the selective uptake of which by the spleen has already been demonstrated. The ternary complex containing pDNA encoding luciferase (pCMV-Luc) exhibited stronger luciferase activity for RAW264.7 mouse macrophage-like cells than naked pCMV-Luc. Although the ternary complex exhibited strong luciferase activity in the spleen after its tail vein injection, luciferase activity in the liver and spleen was significantly decreased by a pretreatment with clodronate liposomes, which depleted macrophages in the liver and spleen. These results indicate that the ternary complex is mainly transfected in macrophages and is a suitable formulation for DNA vaccination. We applied the ternary complex to a pUb-M melanoma DNA vaccine. The ternary complex containing pUb-M suppressed the growth of melanoma and lung metastasis by B16-F10 mouse melanoma cells. We also examined the acute and liver toxicities of the pUb-M ternary complex at an excess pDNA dose in mice. All mice survived the injection of the excess amount of the ternary complex. Liver toxicity was negligible in mice injected with the excess amount of the ternary complex. In conclusion, we herein confirmed that the ternary complex was mainly transfected into macrophages in the spleen after its tail vein injection. We also showed the prevention of melanoma metastasis by the DNA vaccine and the safety of the ternary complex.

Sensitive and real-time method for evaluating corneal barrier considering tear flow.

We developed a new electrophysiological method mimicking tear flow to evaluate the epithelial tight junction of rabbit cornea quantitatively. We investigated the effect of tear flow on the corneal damage induced by ophthalmic preservatives using this method. An Ussing chamber system with Ag/AgCl electrodes was used in the electrophysiological experiment. The excised rabbit cornea was mounted in the Ussing chamber and the precorneal solution in the chamber was perfused with a peristaltic pump at the rate of human tear flow. Corneal transepithelial electrical resistance (TEER) was monitored as corneal barrier ability. In the electrophysiological method mimicking tear flow, we observed stable TEER, which rapidly decreased with benzalkonium chloride (BAC), an eye drop preservative. Using this system, we first found that 0.004% BAC decreased corneal TEER reversibly. A high concentration of BAC showed strong irreversible damage to the tight junction. The influence of BAC on corneal TEER was not only concentration-dependent but also tear flow rate-dependent. The electrophysiological method mimicking tear flow was useful to evaluate the corneal barrier quantitatively. Using this method, we clarified that the tear flow was important to protect the corneal damage induced by preservatives.

Optimization of pH Elution Conditions in Immune Complexome Analysis for Comprehensive Identification of Immune Complex Antigens.

The identification of antigens incorporated into immune complexes (IC-antigens) is important for studying the pathophysiology of immunological diseases. Immune complexome analysis identifies IC-antigens by analyzing ICs collected from biological fluids by IC-capturing beads. In this study, we optimized the method to improve its comprehensiveness while maintaining selectivity for IC-antigens by comparing the number of identified peptides (model IC experiment) or proteins (human pooled serum) eluted from Protein G beads using different pH solutions (pH 2.0 - 11.0).

Effects of Tissue Pressure on Transgene Expression Characteristics via Renal Local Administration Routes from Ureter or Renal Artery in the Rat Kidney.

We previously developed a renal pressure-mediated transfection method (renal pressure method) as a kidney-specific in vivo gene delivery system. However, additional information on selecting other injection routes and applicable animals remains unclear. In this study, we selected renal arterial and ureteral injections as local administration routes and evaluated the characteristics of gene delivery such as efficacy, safety, and distribution in pressured kidney of rat. Immediately after the naked pDNA injection, via renal artery or ureter, the left kidney of the rat was pressured using a pressure controlling device. Transfection efficiency of the pressured kidney was about 100-fold higher than that of the injection only group in both administration routes. The optimal pressure intensity in the rat kidney was 1.2 N/cm2 for renal arterial injection and 0.9 N/cm2 for ureteral injection. We found that transgene expression site differs according to administration route: cortical fibroblasts and renal tubule in renal arterial injection and cortical and medullary tubule and medullary collecting duct in ureteral injection. This is the first report to demonstrate that the renal pressure method can also be effective, after renal arterial and ureteral injections, in rat kidney.