A series of substituted oxindole derivatives was synthesized and evaluated for growth hormone (GH) releasing activity using cultured rat pituitary cells. (+)-6-Carbamoyl-3-(2-chlorophenyl)-(2-diethylaminoethyl)-4-trifluoromethyloxindole (SM-130686, 37S) was found to have potent activity (EC(50) = 3.0 nM), while the other enantiomer 37R had reduced activity. The absolute configuration of 37S was confirmed by X-ray crystallographic analysis. Compound 37S showed a good pharmacokinetic profile in rats with 28% oral bioavailability at 10 mg/kg and excellent in vivo activity as evidenced by a significant weight gain after 4 days of oral administration at 10 mg/kg twice a day. Compound 37S displaced the binding of (35)S-MK-677 to human GHS-R with an IC(50) value of 1.2 +/- 0.2 nM.
benzamide (SMP-534) reduces extracellular matrix (ECM) production induced by transforming growth factor- (TGF-) in vitro and prevents the accumulation of ECM in glomeruli in rat Thy-1 nephritis models. In this study, we examined the longterm effects of SMP-534 on renal insufficiency and glomerulosclerosis in db/db mice, which are models of type 2 diabetes. A diet containing SMP-534 was given to the mice from the age of 9 to 25 wk, and blood and urine analysis were performed at 8, 17, and 25 wk. At the end of study, kidney tissues were analyzed histologically. Treatment with SMP-534 dose dependently suppressed the increase of urinary albumin and type IV collagen excretion in db/db mice. The renal histological analysis showed that SMP-534 dose dependently suppressed the increase of mesangial expansion in the kidney. In the immunohistological analysis, fibronectin and type IV collagen expression were lower in SMP-534-treated db/db mice compared with vehicle-treated db/db mice. This study suggested that SMP-534 ameliorated the increase of ECM production in kidney of db/db mice, possibly through the inhibition of TGF- action. Hence, antifibrotic agents such as SMP-534 might be a new therapeutic option for the treatment of diabetic nephropathy. urinary type IV collagen; diabetic nephropathy; antifibrotic agent; extracellular matrix; transforming growth factor-
Transforming growth factor-beta (TGF-beta) is a potent fibrotic factor responsible for the synthesis of extracellular matrix (ECM) and is implicated as the major determinant in pathogenesis of chronic fibroses, including kidney. The novel small compound SMP-534 reduced ECM production induced by TGF-beta in fibroblast cells. SMP-534 inhibited TGF-beta-induced p38 mitogen-activated protein kinase (p38) activation but did not inhibit epidermal growth factor (EGF)-induced extracellular signal-related kinase (ERK) activation. We also found that oral administration of SMP-534 dose dependently lowered hydroxyproline contents in the cortical region of the kidney in rat anti-Thy-1 nephritis models. In periodic acid-Schiff staining of kidney sections, ECM accumulation was reduced by SMP-534 treatment. These data indicate that SMP-534 has potential in therapy for fibrotic diseases, including nephropathy.
Positron emission tomography (PET) imaging can assist in the early-phase diagnostic and therapeutic evaluation of tumors. Here, we report the radiosynthesis, small animal PET imaging, and biological evaluation of a L-type amino acid transporter 1 (LAT1)-specific PET probe, 18F-FIMP. This probe demonstrates increased tumor specificity, compared to existing tumor-specific PET probes (18F-FET, 11C-MET, and 18F-FDG). Evaluation of probes by in vivo PET imaging, 18F-FIMP showed intense accumulation in LAT1-positive tumor tissues, but not in inflamed lesions, whereas intense accumulation of 18F-FDG was observed in both tumor tissues and in inflamed lesions. Metabolite analysis showed that 18F-FIMP was stable in liver microsomes, and mice tissues (plasma, urine, liver, pancreas, and tumor). Investigation of the protein incorporation of 18F-FIMP showed that it was not incorporated into protein. Furthermore, the expected mean absorbed dose of 18F-FIMP in humans was comparable or slightly higher than that of 18F-FDG and indicated that 18F-FIMP may be a safe PET probe for use in humans. 18F-FIMP may provide improved specificity for tumor diagnosis, compared to 18F-FDG, 18F-FET, and 11C-MET. This probe may be suitable for PET imaging for glioblastoma and the early-phase monitoring of cancer therapy outcomes.
Background/Aims: Diabetic nephropathy is the main cause of end-stage renal disease. Previously we have demonstrated that SMP-534 (an antifibrotic agent) prevents the development of diabetic nephropathy in db/db mouse and that combined treatment with SMP-534 and losartan (antihypertensive agents) markedly prevents the development of diabetic nephropathy compared with single treatment. SMP-534 or losartan was prophylactically administered to db/db mice before the onset of diabetic nephropathy. In the present study, we evaluated the efficacy of combined treatment when administration was started after the onset of diabetic nephropathy. Methods:db/db mice were raised untreated until 17 weeks of age, by which time increase of urinary albumin was noted, and then treated with SMP-534 and/or losartan for another 8 weeks. Biochemical and histological analyses were performed at 25 weeks of age. Results: Combined treatment with SMP-534 and losartan markedly prevented the increase ofurinary albumin and ameliorated the progression of mesangial matrix expansion, even when administration was started long after the increase of urinary albumin. Conclusion: The study results indicate that a combination of SMP-534 and losartan might be a valuable therapeutic approach for the treatment of diabetic nephropathy even when administration is started after the onset of diabetic nephropathy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.