RESUMO
Estrogen receptor-binding fragment associated antigen 9 (EBAG9) exerts tumor-promoting effects by inducing immune escape. We focused on the physiological functions of EBAG9 by investigating the bone phenotypes of Ebag9-knockout mice. Female Ebag9-knockout mice have fragile bones with lower bone mineral density (BMD) compared with wild-type mice. Histomorphometric analyses demonstrated that lower BMD was mainly caused by decreased bone formation. Serum bone turnover markers showed that enhanced bone resorption also contributed to this phenotype. We revealed that EBAG9 promoted autophagy in both osteoblastic and osteoclastic lineages. In addition, the knockdown of Tm9sf1, a gene encoding a protein that functionally interacts with EBAG9, suppressed autophagy and osteoblastic differentiation of the murine preosteoblastic cell line MC3T3-E1. Finally, overexpression of TM9SF1 rescued the suppression of autophagy caused by the silencing of Ebag9. These results suggest that EBAG9 plays a physiological role in bone maintenance by promoting autophagy together with its interactor TM9SF1.
RESUMO
BACKGROUND: Chronic hyperglycemia in diabetes causes atherosclerosis and progresses to diabetic macroangiopathy, and can lead to coronary heart disease, myocardial infarction and cerebrovascular disease. Palmitoleic acid (POA) is a product of endogenous lipogenesis and is present in fish and vegetable oil. In human and animal studies, POA is reported as a beneficial fatty acid related to insulin sensitivity and glucose tolerance. However, few studies have reported its effects on aortic function in diabetes. Here, we investigated the effects of POA administration on vascular function in KKAy mice, a model of type 2 diabetes. METHODS: Male C57BL/6 J (control) and KKAy (experimental) mice at the age of 14 weeks were used in the present study. For each mouse strain, one group was fed with reference diet and a second group was fed POA-containing diet for 2 weeks. The vascular reactivities of prepared aortic rings were then measured in an organ bath to determine if POA administration changed vascular function in these mice. RESULTS: KKAy mice treated with POA exhibited decreased plasma glucose levels compared with mice treated with reference diet. However, endothelium-dependent vasorelaxant responses to acetylcholine and protease-activated receptor 2 activating protein, which are attenuated in the aorta of KKAy mice compared to C57BL/6 J mice under a reference diet, were not affected by a 2-week POA treatment. In addition, assessment of vasoconstriction revealed that the phenylephrine-induced vasoconstrictive response was enhanced in KKAy mice compared to C57BL/6 J mice under a reference diet, but no effect was observed in KKAy mice fed a POA-containing diet. In contrast, there was an increase in vasoconstriction in C57BL/6 J mice fed the POA-containing diet compared to mice fed a reference diet. Furthermore, the vasoconstriction in aorta in both C57BL/6 J and KKAy mice fed a POA-containing diet were further enhanced under hyperglycemic conditions compared to normal glucose conditions in vitro. In the hyperinsulinemic, and hyperinsulinemic combined with hyperglycemic conditions, vasoconstriction was increased in KKAy mice fed with POA. CONCLUSION: These results suggest that POA intake enhances vasoconstriction under hyperglycemic and hyperinsulinemic conditions, which are characteristics of type 2 diabetes, and may contribute to increased vascular complications in diabetes.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Hiperglicemia , Animais , Aorta , Glicemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Dieta , Ácidos Graxos Monoinsaturados , Humanos , Hiperglicemia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Nonalcoholic steatohepatitis (NASH) is a chronic liver disease that leads to liver cirrhosis and hepatocellular carcinoma. Endothelial dysfunction caused by hepatic lipotoxicity is an underlying NASH pathology observed in the liver and the cardiovascular system. Here, we evaluated the effect of dietary nitrite on a rat NASH model. Stroke-prone, spontaneously hypertensive 5/Dmcr rats were fed a high-fat/high-cholesterol diet to develop the NASH model, with nitrite or captopril (100 mg/L, each) supplementation in drinking water for 8 weeks. The effects of nitrite and captopril were evaluated using immunohistochemical analyses of the liver and heart tissues. Dietary nitrite suppressed liver fibrosis in the rats by reducing oxidative stress, as measured using the protein levels of nicotinamide adenine dinucleotide phosphate oxidase components and inflammatory cell accumulation in the liver. Nitrite lowered the blood pressure in hypertensive NASH rats and suppressed left ventricular chamber enlargement. Similar therapeutic effects were observed in a captopril-treated rat NASH model, suggesting the possibility of a common signaling pathway through which nitrite and captopril improve NASH pathology. In conclusion, dietary nitrite attenuates the development of NASH with cardiovascular involvement in rats and provides an alternative NASH therapeutic strategy.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Captopril/farmacologia , Colesterol , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Fígado/metabolismo , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/etiologia , Nitritos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos , Ratos Endogâmicos SHRRESUMO
γ-Glutamyl carboxylase (GGCX) is a vitamin K (VK)-dependent enzyme that catalyzes the γ-carboxylation of glutamic acid residues in VK-dependent proteins. The anticoagulant warfarin is known to reduce GGCX activity by inhibiting the VK cycle and was recently shown to disrupt spermatogenesis. To explore GGCX function in the testis, here, we generated Sertoli cell-specific Ggcx conditional knockout (Ggcx scKO) mice and investigated their testicular phenotype. Ggcx scKO mice exhibited late-onset male infertility. They possessed morphologically abnormal seminiferous tubules containing multinucleated and apoptotic germ cells, and their sperm concentration and motility were substantially reduced. The localization of connexin 43 (Cx43), a gap junction protein abundantly expressed in Sertoli cells and required for spermatogenesis, was distorted in Ggcx scKO testes, and Cx43 overexpression in Sertoli cells rescued the infertility of Ggcx scKO mice. These results highlight GGCX activity within Sertoli cells, which promotes spermatogenesis by regulating the intercellular connection between Sertoli cells and germ cells.
Assuntos
Carbono-Carbono Ligases/metabolismo , Células Germinativas/metabolismo , Células de Sertoli/metabolismo , Vitamina K/metabolismo , Animais , Conexina 43/genética , Conexina 43/metabolismo , Infertilidade Masculina/genética , Masculino , Camundongos , Espermatogênese/fisiologiaRESUMO
BACKGROUND: n-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are thought to exert protective effects in cardiovascular diseases. In addition, n-3 PUFAs have demonstrated anti-cancer effects in vitro and in vivo. OBJECTIVE: We investigated the anti-cancer effects and mechanism of action of EPA on PC3 prostate cancer cells in vitro. METHODS: PC3 cells were treated with various concentrations of EPA, and cell survival and the abilities of migration and invasion were evaluated. The time course of the growth inhibitory effect of EPA on PC3 cells was also assessed. The mechanism underlying the anti-cancer effects of EPA was investigated by human phosphokinase and human apoptosis antibody arrays, and confirmed by western blot analysis. We also examined the contribution of reactive oxygen species (ROS) to the effects of EPA using the ROS inhibitor N-acetyl cysteine. RESULTS: EPA decreased the survival of PC3 cells in a dose-dependent manner within 3 h of application, with an effective concentration of 500 µmol/L. EPA inhibited proline-rich tyrosine kinase (Pyk)2 and extracellular signal-regulated kinase 1/2 phosphorylation as determined by western blotting and the antibody arrays. The growth of PC3 cells was inhibited by EPA, which was dependent on ROS induction, while EPA inhibited Pyk2 phosphorylation independent of ROS production. CONCLUSIONS: Inhibition of Pyk2 phosphorylation and ROS production contribute to the anticancer effects of EPA on PC3 cells.
Assuntos
Ácido Eicosapentaenoico/farmacologia , Quinase 2 de Adesão Focal/metabolismo , Western Blotting , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Masculino , Células PC-3 , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Low-grade and early-stage endometrial cancer usually has a favorable prognosis, whereas recurrent or metastatic disease is often difficult to cure. Thus, the molecular mechanisms underlying advanced pathophysiology remain to be elucidated. From the perspective of the origin of advanced endometrial cancer, the characterization of cancer stem-like cells (CSCs) will be the first step toward the development of clinical management. We established long-term culturable patient-derived cancer cells (PDCs) from patient endometrial tumors by spheroid cell culture, which is favorable for the enrichment of CSCs. PDC-derived xenograft tumors were generated in immunodeficient NOD/Shi-scid, IL-2RγKO Jic mice. Morphologically, PDCs derived from three distinct patient samples and their xenograft tumors recapitulated the corresponding original patient tumors. Of note, CSC-related genes including ALDH1A1 were upregulated in all of these PDCs, and the therapeutic potentiality of aldehyde dehydrogenase inhibitors was demonstrated. In addition, these PDCs and their patient-derived xenograft (PDX) models exhibited distinct characteristics on the basis of their hormone responsiveness and metastatic features. Interestingly, genes associated with inflammation and tumor immunity were upregulated by 17ß-estradiol in PDC lines with high estrogen receptor expression and were also overexpressed in secondary PDCs obtained from metastatic tumor models. These results suggest that PDC and PDX models from endometrial cancer specimens would be useful to elucidate CSC traits and to develop alternative diagnostic and therapeutic options for advanced disease.
Assuntos
Neoplasias do Endométrio/patologia , Células-Tronco Neoplásicas/citologia , Família Aldeído Desidrogenase 1/análise , Animais , Estradiol/farmacologia , Receptor alfa de Estrogênio/análise , Feminino , Xenoenxertos , Humanos , Camundongos , Retinal Desidrogenase/análise , Esferoides Celulares , Células Tumorais CultivadasRESUMO
Mitochondria are essential organelles to efficiently produce ATP by ATP-synthase, which uses a proton-gradient generated by respiratory chain complexes. We previously demonstrated that COX7RP/COX7A2L/SCAF1 is a key molecule that promotes respiratory supercomplex assembly and regulates energy generation. The contribution of COX7RP to metabolic homeostasis, however, remains to be clarified. In the present study, we showed a metabolic phenotype of Cox7rp knockout (Cox7rpKO) mice, which exhibit lower blood glucose levels after insulin or pyruvate injection. Notably, ATP synthesis rate was reduced in Cox7rpKO mice liver, in accordance with decreased percentages of complex III subunit RISP and complex IV subunit COX1 involved in I + III + IV supercomplex fraction. The present findings suggest that COX7RP-mediated mitochondrial respiration plays crucial roles in the regulation of glucose homeostasis and its impairment will lead to the pathophysiology of metabolic states.
Assuntos
Glicemia/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/genética , Deleção de Genes , Fígado/enzimologia , Mitocôndrias/enzimologia , Trifosfato de Adenosina/biossíntese , Animais , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Expressão Gênica , Insulina/farmacologia , Fígado/química , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Membranas Mitocondriais/química , Membranas Mitocondriais/metabolismo , Fosforilação Oxidativa , Ácido Pirúvico/farmacologia , Receptores Depuradores Classe A/genética , Receptores Depuradores Classe A/metabolismoRESUMO
Estrogen is a hormone that regulates physiological processes and its dysregulation may relate to muscle disorders particularly in female, although the mechanism remains to be elucidated. We here show that estrogen deficiency repressed exercise endurance in female mice whereas the administration of estrogen to ovariectomized mice recovered it. Microarray analysis of mouse muscles showed that mitochondrial uncoupling protein 3 (UCP3) is upregulated by ovariectomy and downregulated by estrogen administration. Intriguingly, ectopic expression of constitutively active estrogen receptor α decreased UCP3 level and increased cellular ATP content in differentiated myoblastic C2C12 cells. Overall, the present study suggests that estrogen plays a critical role in the regulation of energy expenditure and exercise endurance in female.
Assuntos
Regulação para Baixo/fisiologia , Estrogênios/metabolismo , Músculo Esquelético/fisiologia , Condicionamento Físico Animal , Resistência Física/fisiologia , Proteína Desacopladora 3/metabolismo , Animais , Regulação para Baixo/efeitos dos fármacos , Estrogênios/farmacologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/efeitos dos fármacos , Ovariectomia , Resistência Física/efeitos dos fármacosRESUMO
Vitamin K is a fat-soluble vitamin that is necessary for blood coagulation. In addition, it has bone-protective effects. Vitamin K functions as a cofactor of γ-glutamyl carboxylase (GGCX), which activates its substrates by carboxylation. These substrates are found throughout the body and examples include hepatic blood coagulation factors. Furthermore, vitamin K functions as a ligand of the nuclear receptor known as steroid and xenobiotic receptor (SXR) and its murine ortholog, pregnane X receptor (PXR). We have previously reported on the bone-protective role of SXR/PXR signaling by demonstrating that systemic Pxr-knockout mice displayed osteopenia. Because systemic Ggcx-knockout mice die shortly after birth from severe hemorrhage, the GGCX-mediated effect of vitamin K on bone metabolism has been difficult to evaluate. In this work, we utilized Ggcx-floxed mice to generate osteoblast-specific GGCX-deficient (Ggcx(Δobl/Δobl)) mice by crossing them with Col1-Cre mice. The bone mineral density (BMD) of Ggcx(Δobl/Δobl) mice was significantly higher than that of control Col1-Cre (Ggcx(+/+)) mice. Histomorphometrical analysis of trabecular bones in the proximal tibia showed increased osteoid volume and a higher rate of bone formation in Ggcx(Δobl/Δobl) mice. Histomorphometrical analysis of cortical bones revealed a thicker cortical width and a higher rate of bone formation in Ggcx(Δobl/Δobl) mice. Electron microscopic examination revealed disassembly of mineralized nodules and aberrant calcification of collagen fibers in Ggcx(Δobl/Δobl) mice. The mechanical properties of bones from Ggcx(Δobl/Δobl) mice tended to be stronger than those from control Ggcx(+/+) mice. These results suggest that GGCX in osteoblasts functions to prevent abnormal mineralization in bone formation, although this function may not be a prerequisite for the bone-protective effect of vitamin K.
Assuntos
Calcificação Fisiológica , Carbono-Carbono Ligases/deficiência , Osteoblastos/enzimologia , Osteogênese , Animais , Fenômenos Biomecânicos , Densidade Óssea , Carbono-Carbono Ligases/metabolismo , Fêmur/patologia , Fêmur/fisiopatologia , Camundongos , Especificidade de Órgãos , Osteoblastos/patologia , Tíbia/patologia , Tíbia/fisiopatologia , Tíbia/ultraestruturaRESUMO
Vitamin K-dependent γ-glutamyl carboxylase (GGCX) is an enzyme that catalyzes the conversion of glutamic acid to gamma-carboxyglutamic acid in substrate proteins. Among GGCX target proteins, recent evidence indicates that osteocalcin regulates insulin sensitivity and secretion. However, the precise contribution of GGCX to glucose metabolism remains to be clarified. To address this question, we generated osteoblast-specific Ggcx-deficient (i.e., conditional knockout [cKO]) mice using collagen type 1 α1 (Col1)-Cre mice. Ggcx cKO mice exhibited altered metabolism compared with their controls; serum glucose levels could be maintained with low amounts of insulin, and the weight of white adipose tissue (WAT) significantly decreased in Ggcx cKO mice. Our findings suggest that GGCX expressed in osteoblasts is critical for the maintenance of blood glucose and WAT.
Assuntos
Carbono-Carbono Ligases/metabolismo , Glucose/metabolismo , Osteoblastos/enzimologia , Animais , Carbono-Carbono Ligases/genética , Teste de Tolerância a Glucose , Masculino , Camundongos , Camundongos KnockoutRESUMO
Vitamin K is a fat-soluble vitamin that plays important roles in blood coagulation and bone metabolism. One of its functions is as a co-factor for γ-glutamyl carboxylase (Ggcx). Conventional knockout of Ggcx causes death shortly after birth in homozygous mice. We created Ggcx-floxed mice by inserting loxP sequences at the sites flanking exon 6 of Ggcx. By mating these mice with albumin-Cre mice, we generated Ggcx-deficient mice specifically in hepatocytes (Ggcx(Δliver/Δliver) mice). In contrast to conventional Ggcx knockout mice, Ggcx(Δliver/Δliver) mice had very low activity of Ggcx in the liver and survived several weeks after birth. Furthermore, compared with heterozygous mice (Ggcx(+/Δliver) ), Ggcx(Δliver/Δliver) mice had shorter life spans. Ggcx(Δliver/Δliver) mice displayed bleeding diathesis, which was accompanied by decreased activity of coagulation factors II and IX. Ggcx-floxed mice can prove useful in examining Ggcx functions in vivo.
Assuntos
Carbono-Carbono Ligases/deficiência , Transtornos Hemorrágicos/enzimologia , Transtornos Hemorrágicos/patologia , Fígado/enzimologia , Longevidade , Animais , Carbono-Carbono Ligases/metabolismo , Deleção de Genes , Hepatócitos/enzimologia , Hepatócitos/patologia , Integrases/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Especificidade de ÓrgãosRESUMO
The mitochondrial respiratory chain is essential for oxidative phosphorylation and comprises multiple complexes, including cytochrome c oxidase, assembled in macromolecular supercomplexes. Little is known about factors that contribute to supercomplex organization. Here we identify COX7RP as a factor that promotes supercomplex assembly. Cox7rp-knockout mice exhibit decreased muscular activity and heat production failure in the cold due to reduced COX activity. In contrast, COX7RP-transgenic mice exhibit increased exercise performance with increased cytochrome c oxidase activity. Two-dimensional blue native electrophoresis reveals that COX7RP is a key molecule that promotes assembly of the III2/IVn supercomplex with complex I. Our study identified COX7RP as a protein that functions in I/III2/IVn supercomplex assembly and is required for full activity of mitochondrial respiration.
Assuntos
Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Mitocôndrias Musculares/enzimologia , Músculo Esquelético/enzimologia , Animais , Regulação da Temperatura Corporal , Complexo I de Transporte de Elétrons/genética , Complexo III da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Transgênicos , Mitocôndrias Musculares/genética , Fosforilação OxidativaRESUMO
The effect on weight reduction of fish oil combined with food restriction in comparison with that of beef tallow was investigated in high-fat diet-induced obese KKAy mice. Although the reduction of body and white adipose tissue weight was similar in the two groups, fish oil increased adiponectin levels in the plasma, improved dyslipidemia accompanied by suppression of lipid synthesis in the liver when compared with beef tallow.
Assuntos
Gorduras na Dieta/administração & dosagem , Dislipidemias/tratamento farmacológico , Gorduras/farmacologia , Óleos de Peixe/farmacologia , Adiponectina/sangue , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Bovinos , Dieta Hiperlipídica , Dislipidemias/sangue , Dislipidemias/etiologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Obesos , Redução de Peso/efeitos dos fármacosRESUMO
We investigated whether oral administration of palmitoleate ameliorates disorders of lipid metabolism to clarify the effects of one of the components of fish oil. Lipid levels in the liver and plasma were significantly decreased by palmitoleate and by EPA administration. These results suggest that palmitoleate, in addition to EPA, plays a role in the regulation of lipid metabolism by fish oil.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Ácido Eicosapentaenoico/farmacologia , Ácidos Graxos Monoinsaturados/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Ácido Eicosapentaenoico/administração & dosagem , Ingestão de Energia/efeitos dos fármacos , Ácidos Graxos Monoinsaturados/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Fish oil is known to improve lifestyle-related diseases. These effects occur partly via activation of PPARs by the n-3 polyunsaturated fatty acids included abundantly in fish oil. We investigated fish oil functions on glucose and lipid metabolism that are both dependent on and independent of PPARs pathway. METHODS: Mice were fed a diet containing 30 en% beef tallow (B diet) for twelve weeks to induce obesity. The mice were then divided into two groups which were fed either a B diet or a diet containing 30 en% fish oil (F diet). Each group was further divided into two groups which were administered PPARα and γ antagonists or vehicle once a day for three weeks. RESULTS: The F diet groups showed lower triglyceride levels in plasma and liver than the B diet groups, but PPARs antagonists did not affect the triglyceride levels in either diet groups. The F diet groups also showed improvement of glucose tolerance compared with the B diet groups. However, PPARs antagonists made glucose tolerance worse in the F diet group but improved it in the B diet group. Therefore, by the administration of antagonists, glucose tolerance was inversely regulated between the B and F diets, and hypolipidemic action in the plasma and liver of the F diet group was not affected. CONCLUSION: These results suggest that fish oil decreases lipid levels in plasma and liver via PPARs pathway-independent mechanism, and that glucose tolerance is inversely regulated by PPARs antagonists under diets containing different oils.
Assuntos
Óleos de Peixe/administração & dosagem , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Obesidade/dietoterapia , PPAR alfa/antagonistas & inibidores , PPAR gama/antagonistas & inibidores , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Tamanho Celular , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/uso terapêutico , Feminino , Óleos de Peixe/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Intolerância à Glucose/sangue , Intolerância à Glucose/dietoterapia , Hipertrigliceridemia/sangue , Hipertrigliceridemia/dietoterapia , Resistência à Insulina , Gordura Intra-Abdominal/efeitos dos fármacos , Gordura Intra-Abdominal/patologia , Lipídeos/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Endogâmicos , Obesidade/sangue , Obesidade/metabolismo , Obesidade/patologia , RNA Mensageiro/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismoRESUMO
The pharmacokinetics of (-)-N-(trans-4-isopropylcyclohexanecarbonyl)-D-phenylalanine (nateglinide) and its enantiomer (L-enantiomer) was studied in Goto-Kakizaki (GK) rats after intravenous administration of nateglinide or L-enantiomer at a dose of 40 micromol/kg body weight. Nateglinide, its L-enantiomer and their metabolites in serum, bile and urine were determined. The total clearance (CL(tot)) and the volume of distribution (Vd) was slightly higher for nateglinide than those for L-enantiomer in control rats, although the differences were not statistically significant. The cumulative excretions of L-M1 (major metabolite of L-enantiomer) and L-M2 (major metabolite of L-enantiomer) into bile were almost the same as that of M1 (major metabolite of nateglinide)and M2 (major metabolite of nateglinide). In GK rats, CL(tot) and Vd were higher for nateglinide than those for L-enantiomer. The cumulative excretion of L-M1 and L-M2 were not different from those of M1 and M2, respectively, into bile or urine. CL(tot) and Vd for nateglinide or L-enantiomer in GK rats were not different from those in control rats. The total excretion of M1, M2, L-M1, and L-M2 into bile or urine in GK rats was not substantially different from that of control rats. These results suggest that the L-enantiomer of nateglinide shows higher CL(tot) and Vd compared with nateglinide, especially in the diabetic state.