The Metabolism of Chlorpromazine by Developing Rabbit Liver

1971 ◽  
Vol 49 (7) ◽  
pp. 649-656 ◽  
Author(s):  
S. P. Bhatnagar

The developmental pattern of various metabolic pathways involved in the detoxification of chlorpromazine was investigated in rabbits by employing hepatic microsomal enzyme preparations and the isolated perfused liver technique. The sulfoxidation and hydroxylation at position 7 of the phenothiazine ring and mono- and di-demethylation of the aliphatic side-chain of sulfides, sulfoxides, and the hydroxylated derivatives constituted the principal metabolic pathways in adult animals, as characterized by thin-layer chromatography. The activity of 3-day-old liver was limited to the sulfoxidation, hydroxylation, and mono-demethylation of the parent compound while fetal liver, 4 days before term, could only effect the sulfoxidation reaction. The transformation in fetus and neonate appeared to progress better when the livers were perfused with whole blood under physiological conditions. Phenobarbital pretreatment accelerated the formation of various metabolites by both the adult and neonatal livers but not by the fetal livers. The stimulatory effect was completely abolished by in vivo administration of DL-ethionine. SKF 525-A caused a substantial in vivo and in vitro inhibition of the drug-metabolizing activity, regardless of the phenobarbital pretreatment.

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Feifei Sun ◽  
Huiyan Zhang ◽  
Gerard Bryan Gonzales ◽  
Jinhui Zhou ◽  
Yi Li ◽  
...  

ABSTRACT Retapamulin, a semisynthetic pleuromutilin derivative, is exclusively used for the topical short-term medication of impetigo and staphylococcal infections. In the present study, we report that retapamulin is adequately and rapidly metabolized in vitro via various metabolic pathways, such as hydroxylation, including mono-, di-, and trihydroxylation, and demethylation. Like tiamulin and valnemulin, the major metabolic routes of retapamulin were hydroxylation at the 2β and 8α positions of the mutilin moiety. Moreover, in vivo metabolism concurred with the results of the in vitro assays. Additionally, we observed significant interspecies differences in the metabolism of retapamulin. Until now, modifying the side chain was the mainstream method for new drug discovery of the pleuromutilins. This approach, however, could not resolve the low bioavailability and short efficacy of the drugs. Considering the rapid metabolism of the pleuromutilins mediated by cytochrome P450 enzymes, we propose that blocking the active metabolic site (C-2 and C-8 motif) or administering the drug in combination with cytochrome P450 enzyme inhibitors is a promising pathway in the development of novel pleuromutilin drugs with slow metabolism and long efficacy.


2019 ◽  
Vol 5 (4) ◽  
pp. 270-277 ◽  
Author(s):  
Vijay Kumar ◽  
Simranjeet Singh ◽  
Ragini Bhadouria ◽  
Ravindra Singh ◽  
Om Prakash

Holoptelea integrifolia Roxb. Planch (HI) has been used to treat various ailments including obesity, osteoarthritis, arthritis, inflammation, anemia, diabetes etc. To review the major phytochemicals and medicinal properties of HI, exhaustive bibliographic research was designed by means of various scientific search engines and databases. Only 12 phytochemicals have been reported including biologically active compounds like betulin, betulinic acid, epifriedlin, octacosanol, Friedlin, Holoptelin-A and Holoptelin-B. Analytical methods including the Thin Layer Chromatography (TLC), High-Performance Thin Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography With Mass Spectral (LC-MS) analysis have been used to analyze the HI. From medicinal potency point of view, these phytochemicals have a wide range of pharmacological activities such as antioxidant, antibacterial, anti-inflammatory, and anti-tumor. In the current review, it has been noticed that the mechanism of action of HI with biomolecules has not been fully explored. Pharmacology and toxicological studies are very few. This seems a huge literature gap to be fulfilled through the detailed in-vivo and in-vitro studies.


Blood ◽  
2003 ◽  
Vol 101 (5) ◽  
pp. 1801-1809 ◽  
Author(s):  
Yoshihiro Yamada ◽  
Yuichi Oike ◽  
Hisao Ogawa ◽  
Yasuhiro Ito ◽  
Hajime Fujisawa ◽  
...  

Neuropilin-1 (NP-1) is a receptor for vascular endothelial growth factor-165 (VEGF165) and acts as a coreceptor that enhances the function of VEGF165 through VEGF receptor-2 (VEGFR-2). Studies using transgenic and knock-out mice of NP-1 indicated that this molecule is important for vascular development as well as neuronal development. We recently reported that clustered soluble NP-1 phosphorylates VEGFR-2 on endothelial cells with a low dose of VEGF165 and rescues the defective vascularity of the NP-1−/− embryo in vitro and in vivo. Here we show that NP-1 is expressed by CD45+ hematopoietic cells in the fetal liver, can bind VEGF165, and phosphorylates VEGFR-2 on endothelial cells. CD45+NP-1+ cells rescued the defective vasculogenesis and angiogenesis in the NP-1−/− P-Sp (para-aortic splanchnopleural mesodermal region) culture, although CD45+NP-1− cells did not. Moreover, CD45+NP-1+ cells together with VEGF165 induced angiogenesis in an in vivo Matrigel assay and cornea neovascularization assay. The extracellular domain of NP-1 consists of “a,” “b,” and “c” domains, and it is known that the “a” and “c” domains are necessary for dimerization of NP-1. We found that both the “a” and “c” domains are essential for such rescue of defective vascularities in the NP-1 mutant. These results suggest that NP-1 enhances vasculogenesis and angiogenesis exogenously and that dimerization of NP-1 is important for enhancing vascular development. In NP-1−/− embryos, vascular sprouting is impaired at the central nervous system (CNS) and pericardium where VEGF is not abundant, indicating that NP-1–expressing cells are required for normal vascular development.


1996 ◽  
Vol 40 (11) ◽  
pp. 2567-2572 ◽  
Author(s):  
J R Sufrin ◽  
D Rattendi ◽  
A J Spiess ◽  
S Lane ◽  
C J Marasco ◽  
...  

Fifteen purine nucleosides and their O-acetylated ester derivatives were examined for in vitro antitrypanosomal activity against the LAB 110 EATRO isolate of Trypanosoma brucei brucei and two clinical isolates of Trypanosoma brucei rhodesiense. Initial comparisons of activity were made for the LAB 110 EATRO isolate. Three nucleoside analogs exhibited no significant activity (50% inhibitory concentrations [IC50s] of > 100 microM), whether they were O acetylated or unacetylated; three nucleosides showed almost equal activity (IC50s of < 5 microM) for the parent compound and the O-acetylated derivative; nine nucleosides showed significantly improved activity (> or = 3-fold) upon O acetylation; of these nine analogs, six displayed activity at least 10-fold greater than that of their parent nucleosides. The most significant results were those for four apparently inactive compounds which, upon O acetylation, displayed IC50s of < or = 25 microM. When the series of compounds was tested against T. brucei rhodesiense isolates (KETRI 243 and KETRI 269), their antitrypanosomal effects were comparable to those observed for the EATRO 110 strain. Thus, our studies of purine nucleosides have determined that O acetylation consistently improved their in vitro antitrypanosomal activity. This observed phenomenon was independent of their cellular enzyme targets (i.e., S-adenosylmethionine, polyamine, or purine salvage pathways). On the basis of our results, the routine preparation of O-acetylated purine nucleosides for in vitro screening of antitrypanosomal activity is recommended, since O acetylation transformed several inactive nucleosides into compounds with significant activity, presumably by improving uptake characteristics. O-acetylated purine nucleosides may offer in vivo therapeutic advantages compared with their parent nucleosides, and this possibility should be considered in future evaluations of this structural class of trypanocides.


1992 ◽  
Vol 12 (2) ◽  
pp. 518-530
Author(s):  
R Palacios ◽  
J Samaridis

We describe here the development and characterization of the FLS4.1 stromal line derived from 15-day fetal liver of BALB/c embryos and defined culture conditions that efficiently support the cloning and long-term growth of nontransformed B-220+ 14-day fetal liver cells at two stages of B-cell development, namely, pro-B lymphocytes (immunoglobulin [Ig] genes in germ line configuration) and pre-B cells (JH-rearranged genes with both light-chain Ig genes in the germ line state). All B-cell precursor clones require recombinant interleukin-7 (rIL-7) and FLS4.1 stromal cells for continuous growth in culture, but pro-B lymphocyte clones can also proliferate in rIL-3. None proliferate in rIL-1, rIL-2, rIL-4, rIL-5, rIL-6, or leukemia inhibitory factor. FLS4.1 stromal cells synthesize mRNA for Steel factor but not for IL-1 to IL-7; all pro-B and pre-B clones express c-Kit, the receptor for Steel factor, and a c-Kit-specific antibody inhibits the enhanced proliferative response of fetal liver B-220+ B-cell precursors supported by FLS4.1 stromal cells and exogenous rIL-7 but does not affect that promoted by rIL-7 alone. Northern (RNA) blot analysis of the expression of the MB-1, lambda 5, Vpre-B, c mu, RAG-1, and RAG-2 genes in pro-B and pre-B clones show that transcription of the MB-1 gene precedes IgH gene rearrangement and RNA synthesis from c mu, RAG-1, RAG-2, lambda 5, and Vpre-B genes. All clones at the pre-B-cell stage synthesize mRNA for c mu, RAG-1, and RAG-2 genes; transcription of the lambda 5 and Vpre-B genes seems to start after D-to-JH rearrangement in B-cell precursors, indicating that the proteins encoded by either gene are not required for B-cell progenitors to undergo D-to-JH gene rearrangement. These findings mark transcription of the MB-1 gene as one of the earliest molecular events in commitment to develop along the B-lymphocyte pathway. Indeed, both pro-B and pre-B clones can generate in vitro and in vivo B lymphocytes but not T lymphocytes; moreover, these clones do not express the CD3-gamma T-cell-specific gene, nor do they have rearranged gamma, delta, or beta T-cell antigen receptor genes.


1979 ◽  
Vol 34 (11) ◽  
pp. 948-950 ◽  
Author(s):  
Carl Fedtke ◽  
Robert R. Schmidt

Abstract The enzymatic activity from sugar beet leaves which is responsible for the detoxification of the herbicide metamitron (4-amino-4,5-dihydro-3-methyl-6-phenyl-1, 2, 4-triazin-5-one, trade name Goltix®) has been characterized in vitro. The detoxification occurs by rapid deamination in vivo as well as in vitro. However, the deamination in vitro is only maximal under reducing conditions, i. e. with an electron donor and in a nitrogen atmosphere. The electron donor may be cystein, glutathione, dithionite or ascorbate. The enzymatic deamination further requires the addition of cytochrome c and a “supernatant factor”, which may be replaced by FMN, FAD or DCPIP. However, in the presence of FMN or DCPIP cytochrome c is not essential but only stimulatory. The partic­ulate as well as the soluble metamitron deaminating enzyme preparations obtained take up oxygen when supplied with cysteine and FMN. The particulate enzyme appears in the peroxysome-fraction. It is therefore suggested, that the enzymatic deamination of metamitron in sugar beet leaves is mediated by a proxisomal membrane bound electron transport system which alternatively may reduce oxygen or metamitron (deaminating).


Blood ◽  
2007 ◽  
Vol 110 (6) ◽  
pp. 2173-2181 ◽  
Author(s):  
Benjamin T. Spike ◽  
Benjamin C. Dibling ◽  
Kay F. Macleod

Abstract Definitive erythropoiesis occurs in islands composed of a central macrophage in contact with differentiating erythroblasts. Erythroid maturation including enucleation can also occur in the absence of macrophages both in vivo and in vitro. We reported previously that loss of Rb induces cell-autonomous defects in red cell maturation under stress conditions, while other reports have suggested that the failure of Rb-null erythroblasts to enucleate is due to defects in associated macrophages. Here we show that erythropoietic islands are disrupted by hypoxic stress, such as occurs in the Rb-null fetal liver, that Rb−/− macrophages are competent for erythropoietic island formation in the absence of exogenous stress and that enucleation defects persist in Rb-null erythroblasts irrespective of macrophage function.


Blood ◽  
2008 ◽  
Vol 111 (6) ◽  
pp. 3211-3219 ◽  
Author(s):  
Shinichi Kitada ◽  
Christina L. Kress ◽  
Maryla Krajewska ◽  
Lee Jia ◽  
Maurizio Pellecchia ◽  
...  

Abstract Altered expression of Bcl-2 family proteins plays central roles in apoptosis dysregulation in cancer and leukemia, promoting malignant cell expansion and contributing to chemoresistance. In this study, we compared the toxicity and efficacy in mice of natural product gossypol and its semisynthetic derivative apo-gossypol, compounds that bind and inhibit antiapoptotic Bcl-2 family proteins. Daily oral dosing studies showed that mice tolerate doses of apogossypol 2- to 4-times higher than gossypol. Hepatotoxicity and gastrointestinal toxicity represented the major adverse activities of gossypol, with apogossypol far less toxic. Efficacy was tested in transgenic mice in which Bcl-2 is overexpressed in B cells, resembling low-grade follicular lymphoma in humans. In vitro, Bcl-2–expressing B cells from transgenic mice were more sensitive to cytotoxicity induced by apogossypol than gossypol, with LD50 values of 3 to 5 μM and 7.5 to 10 μM, respectively. In vivo, using the maximum tolerated dose of gossypol for sequential daily dosing, apogossypol displayed superior activity to gossypol in terms of reducing splenomegaly and reducing B-cell counts in spleens of Bcl-2–transgenic mice. Taken together, these studies indicate that apogossypol is superior to parent compound gossypol with respect to toxicology and efficacy, suggesting that further development of this compound for cancer therapy is warranted.


Blood ◽  
1984 ◽  
Vol 64 (4) ◽  
pp. 930-936 ◽  
Author(s):  
I Max-Audit ◽  
U Testa ◽  
D Kechemir ◽  
M Titeux ◽  
W Vainchenker ◽  
...  

To further investigate the erythroid nature of the two human erythroleukemia cell lines, K562 and HEL-60, and to define the ontogeny of pyruvate kinase (PK) isozymes (R, M2) in developing human erythroid cells, we have studied the isozymic alterations, if any, during differentiation of these cell lines in vitro and normoblasts isolated from fetal liver in vivo. PK activity of erythroleukemic cell lines was intermediate between that observed in leukocytes and in fetal liver erythroblasts. These cell lines contained a high level of M2-PK, but R- PK was always present, albeit at low concentrations, in all the clones or subclones we studied. Erythroblasts from fetal liver were separated according to density on a Stractan gradient. R-PK levels were nearly constant in the different fractions, whereas M2-PK levels markedly decreased as the erythroblasts became mature and almost completely disappeared in late erythroid cells. Thus, these results clearly demonstrate the erythroid origin of these cell lines.


Author(s):  
RIDHI JOSHI ◽  
RISHIKESH MEENA ◽  
PREETI MISHRA ◽  
VIDYA PATNI

Objective: A normal-phase high-performance thin-layer chromatography (HPTLC) method has been developed and validated for estimation and quantitation of beta-sitosterol from the methanolic fraction of different plant parts of two medicinally important plants viz. Merremia aegyptia and Merremia dissecta. These plants have been reported to possess antimicrobial, antioxidant, and anti-inflammatory activities. Methods: Chromatographic separation of beta-sitosterol from the methanolic extracts of plant parts of M. aegyptia and M. dissecta was performed on TLC aluminum plates pre-coated with silica gel 60F254 using a suitable mobile phase. The densitometric scanning was done after derivatization at ????-580 nm for ????-sitosterol. Result: Only M. dissecta leaf sample was reported to contain ????-sitosterol (4.6 ng/μl), whereas other samples such as seed, stem, and callus extracts of M. aegyptia and M. dissecta did not showed its presence. Conclusion: The developed HPTLC method is simple, rapid, and precise and can be used for routine analysis and quantification of ????-sitosterol and other useful plant bioactives that are phytopharmaceutically important.


Sign in / Sign up

Export Citation Format

Share Document