scholarly journals Sterol synthesis in intestinal villi and crypt cells of rats and guinea pigs

1977 ◽  
Vol 18 (3) ◽  
pp. 301-308
Author(s):  
H Muroya ◽  
H S Sodhi ◽  
R G Gould
Keyword(s):  
Guinea Pigs ◽  
Sterol Synthesis ◽  
Intestinal Villi ◽  
Crypt Cells

AN INCREASED RATE OF CHOLESTEROL BIOSYNTHESIS WITH MICROSOME FRACTIONS OF LIVER FROM KETOTIC GUINEA PIGS

1962 ◽  
Vol 40 (1) ◽  
pp. 1749-1762 ◽  
Author(s):  
F. Sauer
Keyword(s):  
Young Adult ◽  
Guinea Pigs ◽  
Cholesterol Synthesis ◽  
Cholesterol Biosynthesis ◽  
Maximum Activity ◽  
Sterol Synthesis ◽  
Differential Centrifugation ◽  
Microsome Fraction ◽  
Liver Homogenates ◽  
Increased Activity

Cholesterol synthesis was studied in liver fractions obtained by differential centrifugation from young, adult, and ketotic guinea pigs. Both 10,000 × g and 105,000 × g sediment was required for maximum activity. Incubations were carried out in the presence of appropriate liver fractions from young guinea pigs in order to overcome the low rates of cholesterol synthesis in liver homogenates from adult guinea pigs. Microsome fractions from ketotic hyperlipemic guinea pigs actively promoted sterol synthesis when incubated with mitochondria plus supernatant from young guinea pigs, while microsome fractions from adult controls (fed or starved) decreased the rate of sterol synthesis in the same incubation system. The results of this investigation indicate that microsomes from hyperlipemic ketotic guinea pigs do not have a block in cholesterol synthesis characteristic of microsomes from starved animals, and that this microsome fraction has increased activity of HMG-CoA2reductase, one of the key enzymes of cholesterol synthesis.

ACETATE METABOLISM IN EXPERIMENTAL KETOSIS OF GUINEA PIGS

1961 ◽  
Vol 39 (4) ◽  
pp. 739-746 ◽  
Author(s):  
Frank Sauer
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Guinea Pigs ◽  
Ketone Bodies ◽  
Acid Synthesis ◽  
Sterol Synthesis ◽  
Acetate Metabolism ◽  
Diabetic Ketosis ◽  
Total Fatty Acids ◽  
Experimental Findings

Non-diabetic ketosis was produced experimentally in fasted pregnant guinea pigs. Total CO2output of ketotic animals was less than that of appropriate controls but there was no impairment in the conversion of acetate-1-C14to C14O2. Sterol synthesis increased in ketotic animals while fatty acid synthesis, particularly in carcass, showed the expected decrease. Ketosis was accompanied by an increase in plasma total fatty acids and in the fatty acid concentration of liver. The experimental findings support the hypothesis that ketosis is a manifestation of increased ketogenesis rather than impaired utilization of ketone bodies.

ACETOACETATE AND β-HYDROXY-β-METHYL GLUTARYL COENZYME A METABOLISM IN NORMAL AND KETOTIC GUINEA PIGS

1961 ◽  
Vol 39 (10) ◽  
pp. 1635-1645 ◽  
Author(s):  
F. Sauer
Keyword(s):  
Guinea Pigs ◽  
Ketone Body ◽  
Coenzyme A ◽  
Sterol Synthesis ◽  
In Vitro Experiments ◽  
Recent Suggestion ◽  
Cleavage Enzyme

Acetoacetate metabolism was studied in normal and ketotic guinea pigs. Labelled acetoacetate was readily utilized by ketotic guinea pigs for oxidation and sterol synthesis. The results do not support the recent suggestion that hyperketonemia results from impaired ketone body utilization.The results of some in vivo and in vitro experiments indicate that although the cleavage of β-hydroxy-β-methylglutaryl CoA (HMG-CoA) is probably the major source of acetoacetate, some acetoacetate synthesis, at least in vitro, may proceed via a pathway that does not involve HMG-CoA.There was no correlation between the degree of activity of the HMG-CoA cleavage enzyme and sterol synthesis.

scholarly journals Oral Infection with Signature-Tagged Listeria monocytogenes Reveals Organ-Specific Growth and Dissemination Routes in Guinea Pigs

2011 ◽  
Vol 80 (2) ◽  
pp. 720-732 ◽  
Author(s):  
Jody A. Melton-Witt ◽  
Susanne M. Rafelski ◽  
Daniel A. Portnoy ◽  
Anna I. Bakardjiev
Keyword(s):  
Listeria Monocytogenes ◽  
Lymph Nodes ◽  
Guinea Pigs ◽  
Mesenteric Lymph Nodes ◽  
Intestinal Villi ◽  
Content Type ◽  
Direct Pathway ◽  
Mesenteric Lymph ◽  
Organ Specific ◽  
Small Intestinal

ABSTRACTListeria monocytogenescauses a serious food-borne disease due to its ability to spread from the intestine to other organs, a process that is poorly understood. In this study we used 20 signature-tagged wild-type clones ofL. monocytogenesin guinea pigs in combination with extensive quantitative data analysis to gain insight into extraintestinal dissemination. We show thatL. monocytogenescolonized the liver in all asymptomatic animals. Spread to the liver occurred as early as 4 h after ingestion via a direct pathway from the intestine to the liver. This direct pathway contributed significantly to the bacterial load in the liver and was followed by a second wave of dissemination via the mesenteric lymph nodes (indirect pathway). Furthermore, bacteria were eliminated in the liver, whereas small intestinal villi provided a niche for bacterial replication, indicating organ-specific differences in net bacterial growth. Bacteria were shed back from intestinal villi into the small intestinal lumen and reinfected the Peyer's patches. Together, these results support a novel dissemination model whereL. monocytogenesreplicates in intestinal villi, is shed into the lumen, and reinfects intestinal immune cells that traffic to liver and mesenteric lymph nodes, a process that occurs even during asymptomatic colonization.

AN INCREASED RATE OF CHOLESTEROL BIOSYNTHESIS WITH MICROSOME FRACTIONS OF LIVER FROM KETOTIC GUINEA PIGS

1962 ◽  
Vol 40 (12) ◽  
pp. 1749-1762 ◽  
Author(s):  
F. Sauer
Keyword(s):  
Young Adult ◽  
Guinea Pigs ◽  
Cholesterol Synthesis ◽  
Cholesterol Biosynthesis ◽  
Maximum Activity ◽  
Sterol Synthesis ◽  
Differential Centrifugation ◽  
Microsome Fraction ◽  
Liver Homogenates ◽  
Increased Activity

Cholesterol synthesis was studied in liver fractions obtained by differential centrifugation from young, adult, and ketotic guinea pigs. Both 10,000 × g and 105,000 × g sediment was required for maximum activity. Incubations were carried out in the presence of appropriate liver fractions from young guinea pigs in order to overcome the low rates of cholesterol synthesis in liver homogenates from adult guinea pigs. Microsome fractions from ketotic hyperlipemic guinea pigs actively promoted sterol synthesis when incubated with mitochondria plus supernatant from young guinea pigs, while microsome fractions from adult controls (fed or starved) decreased the rate of sterol synthesis in the same incubation system. The results of this investigation indicate that microsomes from hyperlipemic ketotic guinea pigs do not have a block in cholesterol synthesis characteristic of microsomes from starved animals, and that this microsome fraction has increased activity of HMG-CoA2reductase, one of the key enzymes of cholesterol synthesis.

Aggregation of macrophages in the tips of intestinal villi in guinea pigs: their possible role in the phagocytosis of effete epithelial cells

1993 ◽  
Vol 271 (3) ◽  
pp. 407-416 ◽  
Author(s):  
Hongxia Han ◽  
Toshihiko Iwanaga ◽  
Yasuo Uchiyama ◽  
Tsuneo Fujita
Keyword(s):  
Epithelial Cells ◽  
Guinea Pigs ◽  
Intestinal Villi

Investigation of the relaxant effects of propofol on ovalbumin-induced asthma in guinea pigs

2006 ◽  
pp. 1
Author(s):  
I. Bagcivan ◽  
O. Cevit ◽  
M. K. Yildirim ◽  
S. Gursoy ◽  
S. Yildirim ◽  
...  
Keyword(s):  
Guinea Pigs

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

1983 ◽  
Vol 41 ◽  
pp. 726-727
Author(s):  
Corazon D. Bucana
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Electron Density ◽  
Peritoneal Cavity ◽  
Ultrastructural Study ◽  
Guinea Pigs ◽  
Random Distribution ◽  
Glycogen Content ◽  
Polymorphonuclear Neutrophils ◽  
Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

Densitometric Identification of Primitive Erythroblasts After Reaction With Diaminobenzidine

1973 ◽  
Vol 31 ◽  
pp. 328-329
Author(s):  
John A. Trotter
Keyword(s):  
Red Blood Cells ◽  
Analytical Method ◽  
Blood Cells ◽  
Guinea Pigs ◽  
Specific Protein ◽  
Visual Examination ◽  
Hemoglobin Synthesis ◽  
Peroxidatic Activity ◽  
Small Density

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).

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