scholarly journals Plasmenylcholine (1-O-alk-1′-enyl-2-acyl-sn-glycero-3-phosphocholine) biosynthesis in guinea-pig heart and liver: cholinephosphotransferase is a bifunctional enzyme for the synthesis of phosphatidylcholine and plasmenylcholine

1994 ◽  
Vol 301 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Y F Xu ◽  
K O ◽  
P C Choy
Keyword(s):  
Guinea Pig ◽  
Significant Proportion ◽  
Specific Radioactivity ◽  
Minor Component ◽  
Guinea Pig Heart ◽  
Chase Period ◽  
Choline Phosphoglycerides ◽  
The Difference ◽  
A Minor ◽  
Guinea Pig Liver

Plasmenylcholine is present in significant proportion (32% of choline phosphoglycerides) in the guinea-pig heart but exists as a minor component (3% of choline phosphoglycerides) in the guinea-pig liver. In this study, the biosynthesis of plasmenylcholine in these two organs was examined. The organs were perfused with labelled choline for 15 min and chased with unlabelled choline for up to 7 h. The labelling of phosphatidylcholine was 6-fold higher than that of plasmenylcholine in the heart and about 60-fold higher in the liver. However, the same labelling ratio was maintained throughout the chase period in both organs. Alterations in the specific radioactivity of CDP-choline caused corresponding changes in the labelling of phosphatidylcholine and plasmenylcholine. Our results suggest that in guinea-pig heart and liver, CDP-choline is the immediate precursor of biosynthesis of phosphatidylcholine and plasmenylcholine. The biochemical cause for the difference in their rates of formation between the two organs was explored. The enzyme activities for the formation of both choline phosphoglycerides were determined. The two reactions share the same characteristics, and 1,2-diacylglycerol and 1-alk-1′-enyl-2-acylglcerol were found to be mutually inhibitory in a competitive fashion. The pool sizes of 1,2-diacylglycerol and 1-alk-1′-enyl-2-acylglycerol were determined, and their ratios were found to be 42 in the heart and 422 in the liver. We conclude that cholinephosphotransferase catalyses the formation of both phosphatidylcholine and plasmenylcholine in the guinea-pig tissues and the rate of plasmenylcholine biosynthesis is dependent on the availability of 1-alk-1′-enyl-2-acylglycerol. Plasmenylcholine biosynthesis is also subjected to modulation by the 1,2-diacylglycerol content of the tissue.

Compensatory hypertrophy and failure in gradual pressure-overloaded guinea pig heart

1989 ◽  
Vol 257 (3) ◽  
pp. H1016-H1024 ◽  
Author(s):  
F. M. Siri ◽  
C. Nordin ◽  
S. M. Factor ◽  
E. Sonnenblick ◽  
R. Aronson
Keyword(s):  
Heart Failure ◽  
Left Ventricular Hypertrophy ◽  
Guinea Pig ◽  
Ventricular Hypertrophy ◽  
Significant Proportion ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Compensatory Hypertrophy ◽  
Guinea Pig Heart ◽  
Ventricular Afterload

Left ventricular hypertrophy has been produced in the guinea pig by a procedure that gradually increases left ventricular afterload. A mildly constricting band was placed around the ascending aortas of very young guinea pigs (225–275 g). With growth to 500–1,000 g, left ventricular systolic pressure increased and left ventricular hypertrophy developed. In approximately 50% of these animals, the hypertrophy was associated with normal left ventricular function and with no unusual symptoms or evidence of heart failure. The other animals developed dyspnea, which appeared an average of 41 days after banding. Dyspneic animals had normal body weight, markedly increased right ventricular and lung weights, decreased left ventricular norepinephrine content, diminished maximum left ventricular pressure generating capacity, and a significantly higher incidence of left ventricular interstitial and perivascular fibrosis. These findings demonstrate that even when left ventricular overload is imposed gradually by banding the aortas of young animals, myocardial decompensation ultimately ensues in a significant proportion of such animals. The slow imposition of loading, the slow rate of decompensation, and the ability to identify animals in heart failure by clinical dyspnea make this model uniquely valuable for studies on the mechanisms of heart failure.

Sevoflurane and Isoflurane Protect the Reperfused Guinea Pig Heart by Reducing Postischemic Adhesion of Polymorphonuclear Neutrophils 

1999 ◽  
Vol 91 (2) ◽  
pp. 521-530 ◽  
Author(s):  
Bernhard Heindl ◽  
Florian M. Reichle ◽  
Stefan Zahler ◽  
Peter F. Conzen ◽  
Bernhard F. Becker
Keyword(s):  
Guinea Pig ◽  
Cardiac Function ◽  
Minimum Alveolar Concentration ◽  
Volatile Anesthetics ◽  
Underlying Mechanism ◽  
Polymorphonuclear Neutrophils ◽  
Guinea Pig Heart ◽  
Cd11b Expression ◽  
Heart Work ◽  
The Difference

Background Polymorphonuclear neutrophils (PMNs) contribute to reperfusion injury. Because volatile anesthetics can reduce PMN adhesion in the reperfused, nonworking heart, the authors analyzed whether this action of volatile anesthetics affects cardiac performance after ischemia and reperfusion and further clarified the underlying mechanism. Methods Isolated guinea pig hearts perfused with crystalloid buffer and performing pressure-volume work were used. Hearts were subjected to 15 min global ischemia and 20 min reperfusion. In the intervention groups an intracoronary bolus of 3 x 10(6) PMNs was applied in the second min of reperfusion, either in the absence or presence of 0.5 or 1 minimum alveolar concentration sevoflurane or isoflurane. The number of sequestered PMNs was calculated from the difference between coronary input and output (coronary effluent) of PMNs. Performance of external heart work, determined pre- and postischemically, served as criterion for recovery of myocardial function. Additionally, the expression of the integrin CD11b on the cell surface of PMN was measured before and after coronary passage. Results Injection of PMN in the reperfusion phase, but not under nonischemic conditions, reduced recovery of external heart work significantly (from 55+/-7% to 19+/-11%). Addition of sevoflurane or isoflurane in concentrations of 0.5 and 1 minimum alveolar concentration to the perfusate reduced postischemic PMN adhesion from 36+/-8% to basal values (20+/-7%) and prevented decline of cardiac function. CD11b expression on PMNs increased significantly during postischemic coronary passage under control conditions. Again, both anesthetics in both concentrations inhibited that activation. Conclusions Volatile anesthetics reduce PMN adhesion in the reperfused coronary system and thereby preserve cardiac function. Reduced expression of the adhesion molecule CD11b on PMNs in the presence of sevoflurane or isoflurane is, at least in part, responsible for the cardioprotective effect.

scholarly journals Low-Mr iron isolated from guinea pig reticulocytes as AMP-Fe and ATP-Fe complexes

1989 ◽  
Vol 261 (3) ◽  
pp. 787-792 ◽  
Author(s):  
J Weaver ◽  
S Pollack
Keyword(s):  
Guinea Pig ◽  
Anion Exchange ◽  
Dominant Species ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Minor Component ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Fe Complexes ◽  
A Minor

Guinea pig reticulocytes were pulse-labelled with 59Fe bound to transferrin. Haemolysates prepared from these reticulocytes were subjected to rapid (NH1)2SO1 precipitation and then chromatography on an anion-exchange resin. ATP-bound 59Fe was the dominant species in the reticulocyte cytosol; 2,3-bisphosphoglycerate and GTP iron complexes were not detected despite the fact that these were stable with (NH1)2SO1 precipitation and readily detected with anion-exchange chromatography. AMP-bound Fe was a minor component of the cytosol following rapid (NH1)2SO4 precipitation, and the major component when iron was released from transferrin by haemolysates. We speculate that ATP-Fe may be degraded in the cell to permit utilization of its iron for haem synthesis.

Does the Csp2—Csp3 barrier in ethylbenzene have a hyperconjugative component? An indirect experimental and theoretical approach

1994 ◽  
Vol 72 (8) ◽  
pp. 1780-1784 ◽  
Author(s):  
Ted Schaefer ◽  
Robert W. Schurko ◽  
Guy M. Bernard
Keyword(s):  
Chemical Shifts ◽  
Minor Component ◽  
Phenyl Group ◽  
Electron System ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Total Magnitude ◽  
The Difference ◽  
A Minor

The proton chemical shifts and the proton spin–spin coupling constants are reported for 1-phenyl-1-butyne and 1-phenyl-1-pentyne dissolved in CS2/C6D12 and acetone-d6. The long-range coupling constants between the methylene and ring protons are used to derive the twofold barriers to internal rotation in these molecules. They are 0.5 ± 0.1 kJ/mol; the perpendicular conformer is the most stable, the one in which the C(3)—C(4) bond of the side chain lies in a plane perpendicular to the phenyl group. This energetic preference is assigned to the difference between C—C and C—H hyperconjugative interactions with the aromatic π electron system, the C—C interaction being larger. Comparison of the twofold components of the internal rotational barriers in biphenyl and diphenylacetylene, that in the latter amounting to 40% of that in the former, implies that the hyperconjugative component of the internal barrier in ethylbenzene is 1.2 ± 0.3 kJ/mol, a minor component of the total magnitude. Molecular orbital computations of the conformational energies of 1 -phenyl-1-butyne all agree that the perpendicular conformer has the lowest energy but only to the extent of 0.1 kJ/mol at most.

scholarly journals HETEROTRANSPLANTATION OF THE THYROID GLAND

1920 ◽  
Vol 31 (6) ◽  
pp. 765-784 ◽  
Author(s):  
Leo Loeb
Keyword(s):  
Connective Tissue ◽  
Guinea Pig ◽  
Fibrous Tissue ◽  
Dead Material ◽  
The Difference ◽  
A Minor ◽  
Almost All ◽  
Primary Injury ◽  
Host Tissues ◽  
Minor Extent

1. After transplantation of the thyroid of the guinea pig into rats there is a primary injury of the transplant, noticeable as early as 3, 4, and 5 days after transplantation. The tissue is less resistant, and it is preserved only under the best conditions. The number of mitoses is much diminished in the transplant, but they may appear even as late as 9 days after transplantation. This was also the latest time at which living tissue was found. Epithelium is best preserved in the neighborhood of growing fibroblastic tissue, and growing epithelium attracts fibroblasts. Few fibroblasts grow between acini, and they have a tendency to form fibrous tissue. Dense fibrous tissue compresses acini and contributes to their destruction. The vascularization of the graft is very poor, but some capillaries may penetrate between acini. The collection of lymphocytes around acini is only casual and may be found where fibroblasts are active and especially around the blood vessels in the capsule of the graft. On the whole, heterotransplanted tissue does not attract lymphocytes to any marked extent. Connective tissue and lymphocytes contribute only secondarily and to a minor extent to the destruction of the heterotransplant. 2. After transplantation of the thyroid of the rabbit into rats the last mitoses are found 9 days after transplantation; living acini are observed as late as 11 days after transplantation, and ducts of squamous epithelium even somewhat later. Different kinds of tissue seem to show a different degree of resistance to the action of heterotoxins. The difference in the resistance to heterotoxins corresponds to the difference in the resistance of various tissues to other kinds of injurious influences. The thyroid of rabbits is, on the whole, better preserved in the rat than the thyroid of the guinea pig; there is also more mitotic activity in the rabbit thyroid. The reaction of the tissues of the host towards heterotransplanted rabbit thyroid in principle is similar to the reaction to heterotransplanted guinea pig thyroid. 3. After transplantation of rabbit thyroid into guinea pigs well preserved thyroid is found not later than 8 days, while the last mitoses appear 6 days after transplantation. The number of mitoses is very small. The host tissues again behave in a manner characteristic of heterotransplantation. It is probable that slight infections and the presence of polynuclear leucocytes are responsible for the somewhat inferior results in this kind of heterotransplantation. 4. After transplantation of cat thyroidinto the rat, signs of degeneration in the transplanted acini appear at the end of the 1st week; they increase during the 2nd week. The last well preserved acini are found at 14 days; a few degenerating acini are still visible as late as 18 days after transplantation. Almost all pieces are entirely necrotic in the 3rd week. Mitoses are only found 5, 9, 10, and 11 days after transplantation, and they are present in a limited number. There is a decided lack of good vascularization in the transplants; it is especially noticeable in the 2nd week after transplantation. Fibroblasts penetrate at various places between the acini and occasionally together with a few lymphocytes may destroy some of them. From the 9th day on the presence of fibrous tissue around the acini is noticeable. It compresses the acini and thus contributes to their destruction. Even the heterotransplanted thyroid exhibits a restraining influence on the connective tissue which is greater than that presented by dead material. The behavior of the lymphocytes towards heterotransplanted thyroid of the cat is similar to that towards other heterotransplanted thyroid.

(S)-Preferential detoxification of 4-hydroxy-2(E)-nonenal enantiomers by hepatic glutathione S-transferase isoforms in guinea-pigs and rats

2001 ◽  
Vol 355 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Akira HIRATSUKA ◽  
Kouichi TOBITA ◽  
Hiroshi SAITO ◽  
Yasuhiro SAKAMOTO ◽  
Hiroaki NAKANO ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
High Catalytic Activity ◽  
Glutathione S Transferase ◽  
Pig Liver ◽  
Liver Cytosol ◽  
Glutathione S Transferases ◽  
Human Livers ◽  
A Minor ◽  
Guinea Pig Liver

In guinea-pig liver cytosol, racemic 4-hydroxy-2(E)-nonenal (HNE), a reactive and highly toxic product released from biomembranes by lipid peroxidation, was detoxified (S)-preferentially by GSH conjugation mediated by glutathione S-transferases (GSTs) and (R)-preferentially by NAD+-dependent oxidation mediated by aldehyde dehydrogenase (ALDH). The GST-mediated detoxification of the HNE enantiomers proceeded at much higher rates than that mediated by ALDH in guinea-pig liver cytosol. All the major guinea-pig GSTs, A1-1, M1-1, M1-2 and M1-3*, isolated from guinea-pig liver cytosol also catalysed the (S)-preferential conjugation of the HNE enantiomers. The liver and other major tissues of guinea-pigs had no immunologically detectable level of a putative GSTA4-4 orthologue, which exists as a minor GST protein in rat, mouse and human livers and exhibits extremely high catalytic activity towards HNE. All the hepatic rat GSTs, A1-1(2), A1-3, A4-4, M1-1, M1-2 and M2-2, also catalysed the (S)-preferential conjugation of HNE enantiomers.

scholarly journals High Expression of a C Protein β Antigen Gene among Invasive Strains from Certain Clonally Related Groups of Type Ia and Ib Group B Streptococci

2002 ◽  
Vol 70 (8) ◽  
pp. 4643-4649 ◽  
Author(s):  
Noriyuki Nagano ◽  
Yukiko Nagano ◽  
Fumiaki Taguchi
Keyword(s):  
Monoclonal Antibody ◽  
Immunoglobulin A ◽  
Minor Component ◽  
Sequencing Analysis ◽  
Group B Streptococci ◽  
C Protein ◽  
Antigen Gene ◽  
The Difference ◽  
Group B ◽  
A Minor

ABSTRACT Serotyped strains of group B streptococci can be divided into subtypes based on restriction endonuclease digestion patterns (RDP). Profiles of cell-bound proteins were compared among RDP types. Proteins that showed a remarkable difference in the degree of expression were found among strains of RDP Ia-3, which has been considered potentially virulent, as well as of RDP Ib-1. For RDP Ia-3 strains, the protein was predominant in strains from cerebrospinal fluid (CSF) but was mostly a minor component in other strains. For RDP Ib-1 strains, the protein was predominant in strains from CSF, showed diversity in strains from blood, and was mostly a minor component in other strains. By N-terminal sequencing analysis, the protein was identified as a C protein β antigen. The level of bound immunoglobulin A (IgA) or anti-β antigen monoclonal antibody correlated with the level of expressed β antigen, and invasive strains showed remarkably high levels of binding; the exception was a CSF-derived strain of RDP Ib-1 which produced a large amount of β antigen and showed a high level of binding of anti-β antigen monoclonal antibody but no IgA binding. PCR-based amplification revealed that the β antigen gene was detected in all RDP Ia-3 and Ib-1 strains but was not found in any strains of other RDP types. Competitive reverse transcriptase PCR demonstrated that the difference in the amount of protein produced was due to the difference in the level of expression of the β antigen mRNA. Our findings imply that differences in gene expression for a protein may contribute to the invasiveness of RDP Ia-3 and Ib-1 strains for the host.

THROMBIN INDEPENDENT TRANSGLUTAMINASE IN VASCULAR CELLS AND TISSUES MAY PROVIDE AN ALTERNATE PATHWAY TOWARD CLOT STABILIZATION

1987 ◽  
Author(s):  
K E Achyuthan ◽  
M J Borowitz ◽  
M A Shuman ◽  
C S Greenberg
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Coagulation Factor ◽  
Muscle Cells ◽  
Vascular Cells ◽  
Pig Liver ◽  
Alternate Pathway ◽  
The Difference ◽  
Guinea Pig Liver

Blood coagulation Factor XIIla (FXIIIa) is a thrombin activated transglutaminase (TG) that is involved in the final step of fibrin stabilization. FXIIIa inhibits fibrinolysis by crosslinking α-2-plasmin inhibitor (α-2-PI) to fibrin. A thrombin-independent TG has been identified in vascular cells and tissues -from human, rabbit, rat, porcine and bovine sources. The vascular TG had several properties similar to the well characterized guinea pig liver TG. Both enzymes had similar molecular weights (80-90 kDa) and similar chromatographic and electrophoretic properties. Both enzymes preferentially crosslinked α-chains of fibrinogen and their TG activities were independent of thrombin treatment. Finally, both enzymes reacted with polyclonal and monoclonal antibodies to guinea pig liver TG. However, the TG from cultured adult bovine aortic endothelial (ABAE) cells exhibited a novel Ca++/Mg++ dependence for enzymatic activity which was distinct from purified liver TG. TG from confluent ABAE cells and rabbit vascular smooth muscle cells had between 4-7 fold higher TG activity compared to rapidly dividing (nonconfluent) cells -from the same passage. The difference in activity was not due to enhanced degradation of TG catalyzed isopeptide bonds by nonconfluent cells Upon examination by immunoblots using anti-TG antibodies, the TG antigen in nonconfluent cells appeared extensively degraded. Furthermore, guanosine-5'-triphosphate (GTP) was nearly 3-fold more inhibitory to TG from confluent cells compared to nonconfluent cells. Proteases, GTP and divalent cation levels may be modulating intracellular TG activity. The TG antigen detected by imm-unohistochemical techniques was predominantly associated with endothelial and smooth muscle cells of arteries, veins, venules and capillaries. TG antigen also codistributed with fibronectin antigen along the hepatic sinusoids. The ABAE cell TG crosslinked α-2-PI to fibrinogen. The modified fibrinogen was 40-fold more resistant to plasminolysis compared to unmodified fibrinogen. In conclusion, the presence of a thrombin-independent TG in blood vessels may provide an alternate pathway to inhibit fibrinolysis and promote clot stabilization.

scholarly journals Different intracellular polyamine concentrations underlie the difference in the inward rectifier K+currents in atria and ventricles of the guinea-pig heart

2005 ◽  
Vol 563 (3) ◽  
pp. 713-724 ◽  
Author(s):  
Ding-Hong Yan ◽  
Kazuhiro Nishimura ◽  
Kaori Yoshida ◽  
Kei Nakahira ◽  
Tsuguhisa Ehara ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Inward Rectifier ◽  
Guinea Pig Heart ◽  
The Difference ◽  
K Currents

Monophasic action potentials during induced hypothermia in hedgehog and guinea pig hearts

1987 ◽  
Vol 253 (5) ◽  
pp. H1083-H1088 ◽  
Author(s):  
G. Duker ◽  
P. O. Sjoquist ◽  
B. W. Johansson
Keyword(s):  
Body Temperature ◽  
Guinea Pig ◽  
Cardiac Electrophysiology ◽  
Simultaneous Recording ◽  
Monophasic Action Potential ◽  
Guinea Pig Heart ◽  
Normal Body Temperature ◽  
Normal Body ◽  
Potential Map ◽  
The Difference

To evaluate mechanisms behind the difference in susceptibility to ventricular fibrillation (VF) between the guinea pig and hedgehog heart, the cardiac electrophysiology of the two species was studied at normal body temperature and at different hypothermic levels by simultaneous recording of the monophasic action potential (MAP) and the external electrocardiogram (ECG). At normal body temperature, the duration of the ventricular MAP was significantly shorter in the hedgehog (93 +/- 8.1 ms) than in the guinea pig (138 +/- 2.6 ms). There was a distinct plateau phase in the guinea pig, whereas no such phase could be detected in the hedgehog. During hypothermia, a similar increase in MAP duration at full repolarization was noticed for both species. However, the prolongation of the MAP at lower repolarization levels was much less in the hedgehog. Besides, hypothermia-induced slow conduction and dispersion of ventricular repolarization was much more apparent in the guinea pig heart compared with the hedgehog heart. These differences may be important factors in the resistance to VF in the hedgehog, at normal body temperature and during hypothermia.

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