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At least 793 records · Page 44Linked to original sources
PubMed1987

An endogenous protein inhibitor of DNA polymerase alpha in normal and neoplastic rat mammary tissues.

Extracts of whole tissue or isolated nuclei from lactating rat mammary gland that has diminished cell replication capacity were more active than the corresponding extracts of pregnant rat mammary gland that contains actively replicating cells in causing a dose-dependent inhibition of DNA polymerase alpha in vitro. Purification of the inhibitor from both tissue and nuclear extracts using a sequence of Sephacryl S200, DEAE-cellulose and CM52 columns confirmed the above assay results. Using the same assay and purification procedures, both tissue and nuclear extracts from the rapidly growing transplanted R3220AC mammary tumors exhibited very little or no inhibitor activity. The partially purified mammary inhibitor (mol. wt of 155kD, high A280 nm/A260 nm ratio, heat labile) was equally inhibitory to the purified DNA polymerase alpha from either R3230AC tumor or calf thymus, and to the nuclear matrix bound DNA polymerase alpha of R3230AC tumor.

Animals↗
PubMed1986

Angiotensin extraction by trout tissues in vivo and metabolism by the perfused gill.

Plasma clearance and tissue accumulation of 125I-angiotensin I, [Asp1, Ile5]ANG I, and [14C]sucrose, an inert volume reference, were measured after a bolus injection into the dorsal aorta of rainbow trout, Salmo gairdneri. Retention and metabolism of ANG I to angiotensin II (ANG II) and their constituent 1-4 peptide by the gill were examined using an isolated perfused arch preparation in which outflow from the respiratory and central filamental (venous) pathways was separated. Clearance of ANG I from plasma is multiexponential, reflecting dilution and tissue extraction. Liver, bile, gonads, corpuscles of Stannius, and white skeletal muscle accumulate more 125I than 14C; gill tissue accumulates less 125I than 14C. ANG I and II are retained by the perfused gill longer than the inert vascular marker sucrose, even though the distribution volumes of the former are less. The gill respiratory pathway converts ANG I to ANG II whereas the venous pathway metabolizes either ANG I or II to the 1-4 peptide and other metabolites. The gill respiratory pathway is in series with the systemic vasculature, has a large blood-cell contact area, and, like the mammalian lung, is ideally suited to activate ANG I. The gill venous pathway is in parallel with the systemic vasculature and removes ANG II from the circulation. During stress, elevated plasma catecholamines may reduce venous perfusion and thereby help maintain elevated circulating ANG II levels through reduced venous metabolism.

Angiotensin I↗
PubMed1989

Dye ligand chromatography and two-dimensional electrophoresis of complex protein extracts from mouse tissue.

A complex protein fraction of mouse brain was subjected to dye ligand chromatography with various dye ligands. The proteins that were bound by the dye-gel matrix and also the non-binding proteins were separated by high-resolution two-dimensional electrophoresis. The protein patterns obtained were compared. The results show that a large number of different protein species bind to dye ligands and do not occur in the eluate. Red A was the most efficient dye in isolating an individual protein class from a complex tissue extract. Moreover, we found that many of the binding proteins did not cross-react among different types of dye ligands. Orange A and Blue B were the most unrelated dyes among those compared. Our investigation shows that dye ligand chromatography can be used as a means (among others employed previously) of fractionating and classifying the enormous number of different protein species in a mammalian tissue when combined with high-resolution two-dimensional electrophoresis.

Animals↗
PubMed1975

Electron microscopical investigations on the glycocalyx of cultivated cells after incubation with extracts from rapidly growing normal and tumour tissues.

Electron microscopical investigations by means of the ruthenium red method on Huggin-tumour cells cultivated in vitro resulted in a different thickness of the glycocalyx depending on the fixation of the cells in monolayer or, after mechanical detachment, in suspension. Cells fixed in suspension display a thicker glycocalyx, which is supposed to be due to a contraction of the cells before fixation. Tissue extracts from rapidly growing tissues (mammary gland of pregnant cows, tumour tissue) cause a significant reduction of the glycocalyx in transformed hamster fibroblasts and Huggin-tumour cells after an 18-hour period of action. These findings are in accordance with previous findings on the glycolytic effect of tissue extracts on sections of cartilaginous tissue. It is discussed whether the action of the tissue extracts on the glycocalyx is due to its detachment or to an inhibition of its renewal.

Animals↗
PubMed1997

Separation of extracts from biological tissues into polycyclic aromatic hydrocarbon, polychlorinated biphenyl and polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran fractions prior to analysis.

A low-pressure liquid chromatography method is presented for separating polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) from biological tissue extracts. After removing lipid from extracts, the PAHs are separated from PCBs and PCDDs/PCDFs on a deactivated 13-24 microns silica gel column. The PCBs are subsequently separated from PCDDs/PCDFs by collecting the first fraction from an automated three column cleanup procedure for PCDDs/PCDFs. The complete method has been used to obtain high recoveries of the three compound classes for analysis by GC-electron capture detection (PCBs) or GC-MS (PAHs and PCDDs/PCDFs).

Animals↗
PubMed1987

Murine "housekeeping" enzyme (genetic locus: Idh-1) is regulated in an allele-specific manner.

The murine "housekeeping" enzyme, cytosolic NADP-isocitrate dehydrogenase (E.C.1.1.1.42) (genetic locus: Idh-1), exhibited a complex pattern of allele-specific expression. Protein electrophoresis on cellulose-acetate gels and determination of relative enzymatic activity by means of densitometry revealed that in heart tissue (but not liver tissue) of certain hybrid crosses the AA-homodimer was underrepresented relative to total enzymatic activity, and the degree of underrepresentation changed during development. In mixtures of homozygous tissue extracts of heart tissue (but not liver tissue) the AA-homodimer was underrepresented relative to the BB-homodimer. Relative activity of allelic isozymes varied as a function of tissue (heart versus liver), age, and the parental source of the Idh-1 alpha allele, but did not vary as a function of sex. Allele-specific expression was also exhibited in kidney tissue of the same animals. In adult male kidney tissue extracts from heterozygotes, the AA-homodimer was underrepresented relative to total enzymatic activity; in adult female kidney tissue extracts from heterozygotes, a more codominant phenotype was observed. Tissue extracts from immature hybrid animals exhibited a phenotype midway between the adult male and adult female phenotypes. Tissue extracts from castrated males exhibited a phenotype equivalent to that seen in females. Relative activity of allelic isozymes in kidney varied as a function of age and sex, but did not vary as a function of the parental source of the Idh-1 alpha allele. While cytosolic NADP-IDH is a "housekeeping" enzyme, expressed in multiple tissues of the mouse, differences in the relative intensities of allelic isozyme bands provide evidence for tissue- and stage-specific regulatory variation.

Alleles↗
PubMed1991

Distribution of plasminogen activator inhibitor (PAI-1) in tissues.

Extracts of human tissue were analysed for plasminogen activator inhibitor (PAI-1) antigen and activity. PAI-1 was localised in tissues by an immunochemical method, using monoclonal antibodies. PAI-1 occurred throughout the body; its concentration and activity differed considerably from organ to organ. Extracts of liver and spleen had the greatest abundance of PAI-1, but the activity of the inhibitor was much higher in liver than in spleen: the liver may be a source of plasma PAI-1. Immunochemical staining for PAI-1 was observed in endothelium, platelets and their precursor cells, the megakaryocytes, and locations central to the process of haemostasis. PAI-1 also occurred in neutrophil polymorphs and macrophages, cells important in inflammatory and immune processes, but not in lymphocytes. Other cell types, in particular, vascular smooth muscle cells and mesangial cells, also stained positively for PAI-1 and such cells seem to represent an important reservoir of PAI-1.

Autopsy↗
PubMed1992

Characterization of two dipeptidases purified from hepatic schistosome egg granulomas in mice. Leukotriene D4 hydrolases of granulomatous tissue.

Extracts prepared from tissue with granulomatous inflammation experimentally produced in liver of CBA-strain mice showed increased hydrolysis of leukotriene D4 (LTD4), Leu-Leu and Ala-Gly as compared with normal hepatic cells. Two dipeptidases, Leu-Leu dipeptidase and Ala-Gly dipeptidase, were purified from hepatic granulomas, and quantitative conversion of LTD4 into leukotriene E4 (LTE4) by both enzymes was demonstrated. M(r) values of the purified enzymes were 178,000 for Leu-Leu dipeptidase and 183,000 for Ala-Gly dipeptidase. The enzymes showed homogeneity, appearing as a single band on SDS/PAGE, and the M(r) values of the subunits were 56,000 and 57,000 for Leu-Leu and Ala-Gly dipeptidase respectively. The amino acid compositions of the two enzymes differed considerably from each other. The activity of Leu-Leu dipeptidase was inhibited by bestatin and captopril and stabilized with MnCl2. The Km for LTD4 was 25 microM with a V(max.) of 49.0 mumols/min per mg. In contrast, the activity of Ala-Gly dipeptidase was inhibited by cilastatin, cytinylglycine, EDTA and dithiothreitol, and also by captopril. The Km for LTD4 was 5.3 microM with a V(max.) of 50.4 mumols/min per mg. The findings indicate that the conversion of LTD4 into LTE4 by microsomal dipeptidases is elevated during granulomatous tissue reaction. This enzyme activity may become useful for biochemical quantification of the pathological tissue reaction that occurs in organized granulomas.

Amino Acid Sequence↗
PubMed1983

Low molecular weight proteinase inhibitors. I. Extraction and identification of activity from normal and malignant human breast tissues.

Extracts of both normal human breast tissues and infiltrating ductal carcinoma tissues were ultrafiltered and concentrated to recover proteins having nominal molecular weights between 1000 and 50,000 daltons. Proteinase inhibitory activity of the final concentrates of tumours and normal breast controls were found to be distinct from the majority of proteinase inhibitory activity in human serum as judged by cellulose acetate electrophoresis. All final concentrates contained proteinase inhibitory activity with electrophoretic mobilities similar to that of Trasylol. Molecular sieve chromatography on high performance liquid chromatographs of the final concentrate of a tumour extract containing the greatest proteinase inhibitory activity indicated that the activity was present within 2 peaks having apparent molecular weights of 22,000 and 7000 daltons.

Adult↗
PubMedDate not supplied

Effects of endotoxin and extracts of pregnant mouse uterus on the recovery of hemopoiesis after 5-fluorouracil.

A single injection of endotoxin, 4 hours after administration of 150 mg/kg of 5-fluorouracil (5-FU), stimulated the recovery of bone marrow hemopoietic cells that form colonies in spleen (CFU-S) or in culture (GM-CFC), of erythropoiesis, and of platelet production. Corynebacterium parvum injections had similar effects. Endotoxin-free extracts of tissues (from pregnant mouse uterus, placenta, and embryo) which have a high content of the factor(s) capable of stimulating growth of GM-CFC in vitro also stimulated recovery of CFU-S and GM-CFC when given in single injections 4 hours after 5-FU. A striking effect of both endotoxin and tissue extracts was the acceleration of the regeneration of a particular subclass of granulocyte macrophage progenitors, those capable of forming large colonies (greater than 0.25 mm) in agar. The results indicate that recovery of hemopoiesis after depression by 5-FU can be stimulated not only by injection of bacterial products, but also by injection of endotoxin-free tissue extracts which contain high levels of hemopoietic regulators.

Animals↗
PubMed1986

Uptake and incorporation of 14C-labelled carbohydrates in the tissues of the reproductive system of the female fowl.

The in vivo incorporation of radioactivity from [14C]GlcN, [14C]GalN, [14C]Glc and [14C]Gal, for different time intervals between 1 and 240 hr into whole tissues, acetone extracted tissues and MPS-P of the different parts of the reproductive system of the female fowl was studied. The incorporation of radioactivity was much more extensive when [14C]GlcN was injected than when [14C]GalN was injected. The incorporation of radioactivity was much more extensive when [14C]HexN was injected than when the corresponding [14C]Hex was injected. This difference of incorporation was greater in the MPS-P than in the fresh or acetone extracted tissues. A comparison was undertaken in the extent that radioactivity was incorporated among the different parts of the reproductive system of the fowl when [14C]HexN and 14C[Hex] were administered.

Animals↗