SPECIES DIFFERENCES IN THE DEOXYRIBONUCLEIC AND RIBONUCLEIC ACID CONTENTS OF LIVERS OF NON-PREGNANT AND PREGNANT MICE, GUINEA-PIGS AND CATS

1953 ◽  
Vol 9 (1) ◽  
pp. 45-51 ◽  
Author(s):  
ROSA M. CAMPBELL ◽  
H. W. KOSTERLITZ
Keyword(s):  
Guinea Pig ◽  
Protein Content ◽  
Liver Cell ◽  
Ribonucleic Acid ◽  
Guinea Pigs ◽  
Deoxyribonucleic Acid ◽  
Species Differences ◽  
Liver Cells ◽  
Maternal Liver ◽  
Pregnant Mice

1. The protein content of liver cells is almost independent of the size of the animal (mice, cats and previous results on rats, Campbell & Kosterlitz [1949]), and varies with the amount of protein eaten. 2. As has already been shown for rats, the ribonucleic acid ('RNA') content of the liver cells of non-pregnant mice, guinea-pigs and cats varies directly with the protein content of the cells. For a given protein content the mouse and rat have more RNA than the guinea-pig and cat. 3. During pregnancy there is a rise of the deoxyribonucleic acid ('DNA') content of the livers and in the protein content of the liver cells of mice (and rats), but not of guinea-pigs. 4. An excess of RNA over that predicted from the protein content of the liver cell has previously been found for the rat during pregnancy, and ascribed to the action of a placental factor on the maternal liver. A similar excess of RNA has now been observed in the mouse and, to a less extent, in the guinea-pig. It appears to be absent in the cat. 5. Possible causes of some of these species differences are considered.

Listeria monocytogenes strains encoding premature stop codons in inlA invade mice and guinea pig fetuses in orally dosed dams

2013 ◽  
Vol 62 (12) ◽  
pp. 1799-1806 ◽  
Author(s):  
Anne Holch ◽  
Hanne Ingmer ◽  
Tine Rask Licht ◽  
Lone Gram
Keyword(s):  
Listeria Monocytogenes ◽  
Guinea Pig ◽  
Food Processing ◽  
Guinea Pigs ◽  
Stop Codon ◽  
Fetal Liver ◽  
Fatal Case ◽  
Premature Stop Codon ◽  
Tissue Samples ◽  
Pregnant Mice

Listeria monocytogenes is an important food-borne bacterial pathogen and listeriosis can result in abortions in pregnant women. The bacterium can colonize food-processing environments, where specific molecular subtypes can persist for years. The purpose of this study was to determine the virulence potential of a group of food-processing persistent L. monocytogenes strains encoding a premature stop codon in inlA (encoding internalin A) by using two orally dosed models, pregnant mice and pregnant guinea pigs. A food-processing persistent strain of L. monocytogenes invaded placentas (n = 58; 10 % positive) and fetuses (3 % positive) of pregnant mice (n = 9 animals per strain), similar to a genetically manipulated murinized strain, EGD-e InlA m* (n = 61; 3 and 2 %, respectively). In pregnant guinea pigs (n = 9 animals per bacterial strain), a maternofetal strain (from a human fetal clinical fatal case) was isolated from 34 % of placenta samples (n = 50), whereas both food-processing persistent strains were found in 5 % of placenta samples (n = 36 or 37). One of the food-processing persistent strains, N53-1, was found in up to 8 % of guinea pig fetal liver and brain samples, whereas the maternofetal control was found in 6 % of fetal tissue samples. As the food-processing persistent strains carry a premature stop codon in inlA but are invasive in orally dosed pregnant mice and guinea pigs, we hypothesize that listerial crossing of the placental barrier can occur by a mechanism that is independent of an interaction between E-cadherin and InlA.

scholarly journals The Effect of Lighted Incubation on Ribonucleic Acid, Deoxyribonucleic Acid, and Protein Content of Chick Embryos

1981 ◽  
Vol 60 (5) ◽  
pp. 1089-1091 ◽  
Author(s):  
MARILYN A. COLEMAN ◽  
ROBERT C. SMITH ◽  
GAYNER R. McDANIEL
Keyword(s):  
Protein Content ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Chick Embryos

THE ROLE OF HORMONAL AND DIETARY FACTORS IN THE FORMATION OF EXCESS RIBONUCLEIC ACID IN THE LIVERS OF PREGNANT RATS

1953 ◽  
Vol 9 (1) ◽  
pp. 52-67 ◽  
Author(s):  
ROSA M. CAMPBELL ◽  
I. R. INNES ◽  
H. W. KOSTERLITZ
Keyword(s):  
Protein Content ◽  
Ribonucleic Acid ◽  
Liver Cells ◽  
Significant Rise ◽  
Dietary Factors ◽  
Pregnant Female ◽  
Female Rats ◽  
Liver Protein ◽  
Pregnant Rats ◽  
Dna And Rna

1. Excess ribonucleic acid ('RNA') is defined as the difference between the RNA contents of livers of pregnant and non-pregnant rats. Large amounts of excess RNA are formed in the liver of the rat during the last week of pregnancy. Excess RNA is formed in the liver after removal, on the 14th or 15th day of pregnancy, of the foetuses, or foetuses and ovaries, or foetuses and adrenals, or foetuses, ovaries and adrenals, or pituitary, or pituitary and foetuses, or pituitary, foetuses and ovaries. Viable placentae must be present. 2. Two fractions of RNA appear to be present in the liver cells of pregnant rats. One fraction varies linearly with the protein content of the liver cells, as does the RNA of non-pregnant rats' livers. The second fraction (excess RNA) is quite independent of the protein content of the liver cells but varies linearly with the weight of the placentae and the energy, but not the protein, content of the diet. 3. Hypophysectomy lowers the amount of excess RNA by 20–25 %. After removal of the foetuses on the 14th day, the placentae do not attain the normal weight, and the amount of excess RNA is smaller than in normal pregnancy. After removal of foetuses and ovaries the placentae are larger and heavier than after removal of the foetuses alone. 4. Both adrenalectomy and ovariectomy in non-pregnant female rats cause a small rise of liver deoxyribonucleic acid ('DNA') and RNA. After hypophysectomy, there is a loss in liver RNA greater than that expected from the simultaneous loss of liver protein. The loss of RNA occurs even when the loss of liver protein is prevented by feeding the rats by stomach tube. DNA is not lost from the liver a fortnight after hypophysectomy, as long as the energy intake is normal. 5. In non-pregnant female rats oestradiol, but not progesterone, causes an increase of liver DNA and RNA. This is not found in hypophysectomized rats. Injection of an alkaline placental extract causes a significant rise of liver RNA which, however, is very much smaller than that found in pregnancy. 6. Since hypophysectomy lowers, but does not abolish excess liver RNA in pregnant rats, it is concluded that at least two factors play a role: first and foremost, an unknown factor secreted by the placenta, acting independently of the pituitary, and second, increased amounts of oestrogen apparently requiring the presence of the pituitary.

Nucleic Acids in Grass and Grass Silage

1988 ◽  
Vol 1988 ◽  
pp. 86-86
Author(s):  
A B McAllan ◽  
G D Braithwaite
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Protein Content ◽  
Ribonucleic Acid ◽  
Protein Fraction ◽  
Dry Matter ◽  
Deoxyribonucleic Acid ◽  
Total N ◽  
Grass Silage ◽  
Microbial N

Little attention has been directed at defining the ‘protein’ fraction of silages. This component is normally estimated by fractionation based on solubility characteristics and under the conditions most commonly used, nucleic acids (ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)) would appear in the protein fraction. Grasses and legumes can contain appreciable amounts of nucleic acids ranging from 11-29 and 19-53 g/kg dry matter respectively (McAllan, 1982). No information is available as to the effects of ensilage on these nucleic acids. Microbes also contain appreciable amounts of nucleic acids which can account for 150-200 gN/kg total-N of the cell and these amounts may vary according to the stage of growth. It has been suggested (Ullrich, 1982) that microbial-N contribution to the total-N content of silage is as much as 220-280 g/kg. Thus the total amount of silage ‘protein-N’ present in the form of nucleic acid-N (from both plant and microbes) could be appreciable leading to a considerable overestimation of the ‘protein’ content of the silage.

Composition of Methanospirillum hungatii GP1 during growth on different media

1980 ◽  
Vol 26 (5) ◽  
pp. 577-582 ◽  
Author(s):  
C. Breuil ◽  
G. B. Patel
Keyword(s):  
Protein Content ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Synthetic Medium ◽  
Density Measurement ◽  
Dry Weight ◽  
Weight Basis ◽  
Total Carbohydrate ◽  
Mineral Salts

Growth of Methanospirillum hungatii GP1 as determined by optical density measurement was comparable to growth assessed by cell dry weight, ribonucleic acid content, and deoxyribonucleic acid content. Cultivation of M. hungatii on synthetic medium containing mineral salts, vitamins, and acetic acid indicated that, on a dry weight basis, cell constituents such as protein (71%), ribonucleic acid (15.8%), deoxyribonucleic acid (1.6%), and total carbohydrate (3.2%) did not vary significantly with the growth phase. Cells grown in the synthetic medium supplemented with yeast extract and tryptone had slightly higher protein content (76%), but the concentrations of the other cell constituents were similar and did not fluctuate much during growth. Nitrogen limiting growth resulted in somewhat lower ribonucleic acid content as well as slightly higher protein content than that in cells grown in nonlimiting medium. Methanospirillum hungatii did not accumulate any of the commonly known reserve materials under nitrogen or carbon and hydrogen limiting growth.

Species differences in pulmonary vasoactive responses to histamine, 5-hydroxytryptamine, and KCl

1993 ◽  
Vol 74 (1) ◽  
pp. 139-146 ◽  
Author(s):  
J. D. Bradley ◽  
P. B. Zanaboni ◽  
T. E. Dahms
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Species Differences ◽  
Venous Occlusion ◽  
Longitudinal Distribution ◽  
Critical Closing Pressure ◽  
Before And After ◽  
Pulmonary Arterial ◽  
Microvascular Resistance

Species differences in the longitudinal distribution of pulmonary vascular resistance (PVR) in response to 5-hydroxytryptamine (5-HT) or histamine (His) may be attributed to variations in the distribution of functional smooth muscle between arteries and veins estimated by the response to KCl. Isolated dog, guinea pig, or rabbit lungs were perfused at a constant flow = 55–75 ml.min-1.kg body wt-1. Pulmonary arterial (Ppa); arterial, double, and venous occlusion (Po,a; Pdo; Po,v, respectively); and pulmonary venous (Ppv) pressures were measured before and after increasing PVR by infusing His, 5-HT, or KCl. 5-HT and His increased Ppa--Pdo in rabbits but Pdo--Ppv in guinea pigs. In dogs, 5-HT increased Ppa--Po,a, but His increased Pdo--Ppv. Dynamic (Co,v) and static vascular compliance (CP-Q), as well as critical closing pressure (Pcc, the gamma-intercept of pressure-flow curves), were also measured. At baseline, Co,v was the same among species. However, CP-Q was higher than Co,v in all lungs and was significantly different among species in order of (in ml.cmH2O-1.100 g-1) rabbit (4.54 +/- 0.28) > guinea pig (3.31 +/- 0.18) > dog (2.21 +/- 0.13). Increases in Pcc correlated with increases in microvascular resistance (Po,a--Po,v) but not with increases in PVR after agonist infusion. KCl responses suggest that guinea pigs and rabbits have relatively more functional smooth muscle in venous and arterial microvessels, respectively, whereas dogs have approximately equal amounts.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Permeability of the liver cell membrane to quinolinate

1977 ◽  
Vol 164 (1) ◽  
pp. 283-286 ◽  
Author(s):  
K R F Elliott ◽  
C I Pogson ◽  
S A Smith
Keyword(s):  
Steady State ◽  
Cell Membrane ◽  
Guinea Pig ◽  
Liver Cell ◽  
Liver Cells ◽  
Pig Liver ◽  
Liver Cell Membrane ◽  
Guinea Pig Liver

Quinolinate was taken up by both rat and guinea-pig liver cells. Equilibrium was reached after approx. 20 min with rat cells, but guinea-pig cells had not achieved a steady state after 60 min. There was no evidence to suggest that quinolinate is rapidly metabolized by either species. The concentrations of quinolinate attained in rat and guinea-pig cells after short periods of incubation with 0.5 mM-quinolinate did not inhibit gluconeogenesis. These results raise further doubts as to the mechanism of quinolinate action in liver.

SPECIES DIFFERENCES IN STEROIDOGENESIS FOLLOWING THE IN VITRO INCUBATION OF DECAPSULATED TESTES

1977 ◽  
Vol 86 (4) ◽  
pp. 851-864 ◽  
Author(s):  
B. de la Torre ◽  
M. Hedman ◽  
E. Diczfalusy
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Species Differences ◽  
Fold Increase ◽  
Human Testis ◽  
Experimental Conditions ◽  
Marked Rise ◽  
Carbon 14 ◽  
Major Increase

ABSTRACT Decapsulated testes of rats, guinea pigs and rabbits were incubated with or without labelled precursors and the steroids formed under various experimental conditions were analysed. Also a decapsulated human testis was incubated with labelled acetate. Cholesterol, testosterone and androstenedione were isolated in a radiochemically homogeneous form following the incubation of carbon-14-labelled sodium acetate with decapsulated testes of all 3 animal species. No other labelled steroid was detected following the incubation of rat testes. Guinea pig testes also converted labelled acetate to pregnenolone. Rabbit and human testes converted labelled acetate to cholesterol, pregnenolone, dehydroepiandrosterone, androstenediol, testosterone and androstenedione. When decapsulated testes of rats, guinea pigs and rabbits were incubated with carbon-14 labelled pregnenolone as a precursor, radiochemically homogeneous progesterone, 17-hydroxypregnenolone, dehydroepiandroster-one, androstenediol, androstenedione and testosterone were isolated in each experiment. Using radioimmunoassay techniques, preformed steroids together with steroids formed from endogenous precursors were analysed following the incubation of rat, guinea pig and rabbit testes in the absence and in the presence of human chorionic gonadotrophin (HCG). Marked (seasonal?) variations were observed between the results of experiments conducted at different times. Incubation of guinea pig testes in the absence as well as in the presence of HCG resulted in a major increase in pregnenolone levels. No such finding was encountered when rat and rabbit testes were incubated. The addition of HCG resulted in at least a 10-fold increase in testosterone formation by the testes of all three species. The addition of HCG to the incubation medium induced a marked rise in dihydrotestosterone levels in the rabbit testes but had no effect whatsoever on the levels of this steroid in guinea pig testes. It is concluded that considerable species differences exist in the steroid metabolism of decapsulated testes incubated in vitro.

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