The Experts below are selected from a list of 13824 Experts worldwide ranked by ideXlab platform
Yasufumi Sawada - One of the best experts on this subject based on the ideXlab platform.
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physiologically based pharmacokinetic model for pralmorelin hydrochloride in rats
Drug Metabolism and Disposition, 2005Co-Authors: Risa Nasu, Yoichi Kumagai, Hirokuni Kogetsu, Hisakazu Ohtani, Masayuki Tsujimoto, Yasufumi SawadaAbstract:Pralmorelin hydrochloride (pralmorelin), consisting of six amino acid residues, is a growth hormone-releasing peptide. The aim of this study is to analyze the pharmacokinetics of pralmorelin after intravenous bolus administration to rats, and to develop a physiologically based pharmacokinetic (PB-PK) model to describe and predict the concentrations of pralmorelin in blood and tissues. Pralmorelin (3 mg/kg) was administered intravenously to 24 Sprague-Dawley rats. Groups of three rats were sacrificed by decapitation at each designated time point (up to 4 h), and plasma and tissues (brain, lung, heart, liver, kidney, small Intestine, Muscle, adipose, and skin) were collected. Bile was also pooled until decapitation. The concentration of pralmorelin in samples was determined by liquid chromatography-tandem mass spectrometry. Plasma concentrations of pralmorelin declined rapidly in a biexponential manner. Biliary excretion of pralmorelin was so rapid that 80% of the dose was recovered unchanged in the bile within 1 h after administration. The distribution parameters in each tissue were obtained by using a hybrid model and an integration plot. They revealed that the distribution of pralmorelin into liver was blood flow-limited, and its distribution was permeability-limited in all other tissues. The PB-PK model developed in this study well described the time courses of pralmorelin concentration in the blood and tissues of rats.
Jean Luc Vilotte - One of the best experts on this subject based on the ideXlab platform.
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Generation of Sprn-regulated reporter mice reveals gonadic spatial expression of the prion-like protein Shadoo in mice
Biochemical and Biophysical Research Communications, 2011Co-Authors: Rachel Young, Sandrine Le Guillou, Gaëlle Tilly, Bruno Passet, Marthe Vilotte, Johan Castille, Vincent Beringue, Fabienne Le Provost, Hubert Laude, Jean Luc VilotteAbstract:The protein Shadoo (Sho) is a paralogue of prion protein, and encoded by the gene Sprn. Like prion protein it is primarily expressed in central nervous system, and has been shown to have a similar expression pattern in certain regions of the brain. We have generated reporter mice carrying a transgene encompassing the Sprn promoter, exon 1, intron 1 and the 5′-end of exon 2 driving expression of either the LacZ or GFP reporter gene to study the expression profile of Shadoo in mice. Expression of the reporter genes was analysed in brains of these transgenic mice and was shown to mimic that of the endogenous gene expression, previously described by Watts et al. [1]. Consequently, the Sprn-LacZ mice were used to study the spatial expression of Sho in other tissues of the adult mouse. Several tissues were collected and stained for β-gal activity, including the thymus, heart, lung, liver, kidney, spleen, Intestine, Muscle, and gonads. From this array of tissues, the transgene was consistently expressed only in specific cell types of the testicle and ovary, suggesting a role for Shadoo in fertility and reproduction. These mice may serve as a useful tool in deciphering the regulation of the prion-like gene Sprn and thus, indirectly, of the Shadoo protein.
K. Murata - One of the best experts on this subject based on the ideXlab platform.
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Rat small Intestine Muscle relaxation alkaloids from Orixa japonica leaves.
Biological & pharmaceutical bulletin, 2001Co-Authors: Shinji Funayama, Y Kumekawa, T Noshita, T Kashiwagura, R. Tanaka, T Mori, K. MurataAbstract:Two quinoline alkaloids, japonine (1) and eduline (2) were isolated from the methanol extract of the leaves of Orixa japonica as relaxants against rat small Intestine Muscle. The activity of these alkaloids was comparable to that of the typical Muscle relaxant papaverine (4). This is also the first report of the isolation of eduline (2) from O. japonica.
Yong Zhu - One of the best experts on this subject based on the ideXlab platform.
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Characterization and expression of the nuclear progestin receptor in zebrafish gonads and brain.
Biology of Reproduction, 2010Co-Authors: Richard N Hanna, Sean C J Daly, Yefei Pang, Isabelle Anglade, Olivier Kah, Peter Thomas, Yong ZhuAbstract:The zebrafish nuclear progestin receptor (nPR; official symbol PGR) was identified and characterized to better understand its role in regulating reproduction in this well-established teleost model. A full-length cDNA was identified that encoded a 617-amino acid residue protein with high homology to PGRs in other vertebrates, and contained five domains characteristic of nuclear steroid receptors. In contrast to the multiplicity of steroid receptors often found in euteleosts and attributed to probable genome duplication, only a single locus encoding the full-length zebrafish pgr was identified. Cytosolic proteins from pgr-transfected cells showed a high affinity (K(d) = 2 nM), saturable, single-binding site specific for a native progestin in euteleosts, 4-pregnen-17,20 beta-diol-3-one (17,20 beta-DHP). Both 17,20 beta-DHP and progesterone were potent inducers of transcriptional activity in cells transiently transfected with pgr in a dual luciferase reporter assay, whereas androgens and estrogens had little potency. The pgr transcript and protein were abundant in the ovaries, testis, and brain and were scarce or undetectable in the Intestine, Muscle, and gills. Further analyses indicate that Pgr was expressed robustly in the preoptic region of the hypothalamus in the brain; proliferating spermatogonia and early spermatocytes in the testis; and in follicular cells and early-stage oocytes (stages I and II), with very low levels within maturationally competent late-stage oocytes (IV) in the ovary. The localization of Pgr suggests that it mediates progestin regulation of reproductive signaling in the brain, early germ cell proliferation in testis, and ovarian follicular functions, but not final oocyte or sperm maturation.
Zhang Hou-li - One of the best experts on this subject based on the ideXlab platform.
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Effects of Hawthorn Alcohol Extract on the Contractility of Isolated Rat Gastric and Intestine Muscle Strips
Progress in Modern Biomedicine, 2009Co-Authors: Zhang Hou-liAbstract:Objective:To investigate the effects of Hawthorn alcohol extract on contractility of isolated rat gastric and Intestine smooth Muscle strips.Methods:Isolated rat Intestine was selected to observe the effects in the presence of acetylcholine with Krebs' solution.Results:Hawthorn alcohol extract could significantly reduce the contractility of rat gastric and Intestine smooth Muscle strips in the range of 5-20 mg crude drugs/ml with a dose-dependent manner, and Hawthorn alcohol extract(20 mg crude drugs/ml) could inhibit the stimulation induced by acetylcholine.Hawthorn alcohol extract(20 mg crude drugs/ml) was found to have an inhibition of the relaxation concurrently used with atropine.Conclusions:The results showed that Hawthorn alcohol extract had prominent inhibitory effects on the contractile activity of isolated rat gastric and Intestine smooth Muscle strips.
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Effects of Charred Fructus Crataegi Alcohol Extract on Contractility Of Isolated Rat Gastric and Intestine Muscle Strips
Progress in Modern Biomedicine, 2009Co-Authors: Zhang Hou-liAbstract:Objective: To investigate the effects of charred fructus crataegi alcohol extract on contractility of isolated rat gastric and Intestine smooth Muscle strips.Methods: Isolated rat Intestine was selected in the assay to test the effects of charred fructus crataegi alcohol extract on contractility of isolated rat gastric and Intestine smooth Muscle strips using Krebs' solution,to observe the effects of in the presence of acetylcholine or atropine.Results: In the range of 2~8mg crude drugs/ml,charred fructus crataegi alcohol extract could reduce significantly the contractility of rat gastric and Intestine smooth Muscle strips in a dose-dependent manner.Charred fructus crataegi alcohol extract(8 mg crude drugs/ml) could inhibit the stimulation induced by acetylcholine and the relaxation concurrently used with at-ropin.Conclusion: Charred fructus crataegi alcohol extract has prominent inhibitory effects on the contractile activity of isolated rat gas-tric and Intestine smooth Muscle strips.
