Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tribulus terrestris L. is an annual plant which has been commonly used in folk medicine as diuretic and against colic pains, hypertension and hypercholesterolemia in Turkey. This study investigated the effects of liophilized saponin mixture of this plant on several smooth muscle preparations in vitro. The liophilized material was obtained from dried and powdered T. terrestris L. by specific extraction method for saponins. Median lethal dose (LD50) of saponin mixture on Swiss albino mice was calculated according to Litchfield-Wilcoxon method via i.p. route. LD50 and its 95% confidence limits were 813 and 739-894 mg.kg-1 respectively. Saponin mixture has caused a significant decrease on peristaltic movements of isolated sheep ureter and rabbit jejunum preparations in a dose-dependent manner (p < 0.05). However it has been observed no effect on isolated rabbit aorta and its contractile response to KCl or noradrenaline (p > 0.05). According to these results it has been suggested that T. terrestris L. or its saponin mixture may be useful on some smooth muscle spasms or colic pains.
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PMID:Effect of Tribulus terrestris L. saponin mixture on some smooth muscle preparations: a preliminary study. 1007 81

Recently, we demonstrated the utility of positron emission tomography (PET) imaging-based pharmacokinetic evaluation studies for preclinical experiments and microdose clinical trials, mainly focused on low molecular weight compounds. In order to investigate the pharmacokinetics of nucleic acid drugs and their drug delivery systems (DDSs) in vivo by using PET imaging, we developed a novel and efficient method for radiolabeling oligodeoxynucleotides with the positron-emitting radionuclide (18)F (stoichiometry-focused Huisgen-type (18)F labeling). By using this method, we succeeded in synthesizing a variety of (18)F-labeled oligodeoxynucleotides with not only phosphodiesters (PO) in natural forms, but also phosphorothioate (PS) and bridged nucleic acid (BNA) in artificial forms, and then performed PET studies and radioactive metabolite analyses of these (18)F-labeled oligodeoxynucleotides. The tissue-distribution and dynamic changes in radioactivity showed significantly different profiles between these antisense oligodeoxynucleotides. The radioactivity of (18)F-labeled PO-DNA and PO-BNA rapidly accumulated in the kidneys and liver and then moved to the renal medulla, ureter, bladder, and intestine. However, the radioactivity of (18)F-labeled PS-DNA and PS-BNA, possessing PS backbone structures, was retained in the blood for relatively long periods and then gradually accumulated in the liver and kidneys. The metabolite analysis showed that (18)F-labeled PO-DNA rapidly degraded by 5min and (18)F-labeled PO-BNA gradually degraded over time by 60min. Conversely, (18)F-labeled PS-DNA and PS-BNA were shown to be much more stable. To demonstrate the usefulness of the PET imaging technique for evaluating the improved targeting potential of the DDS, we designed and synthesized a cholesterol-modified oligodeoxynucleotide, that we developed as an antisense nucleic acid drug against proprotein convertase subtilisin/kexin type 9 (PCSK9) for hypercholesterolemia therapy, and evaluated its pharmacokinetics using PET imaging. As expected, the (18)F-labeled cholesterol-modified PS-BNA-type oligodeoxynucleotide showed much higher and more rapid accumulation in the delivery target organ, that is, the liver, which encourages us to develop this drug. These results suggest that dynamic PET studies using (18)F-incorporated oligodeoxynucleotide synthesized by stoichiometry-focused Huisgen-type labeling is useful for quantitative pharmacokinetic evaluation of nucleic acid drugs and their delivery systems.
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PMID:Quantitative evaluation of the improvement in the pharmacokinetics of a nucleic acid drug delivery system by dynamic PET imaging with (18)F-incorporated oligodeoxynucleotides. 2456 56