Erythroid colony formation by fetal rat liver and spleen cells in vitro: inhibition by a low relative molecular mass component of fetal spleen

Development ◽  
1992 ◽  
Vol 114 (1) ◽  
pp. 213-219
Author(s):  
M.D. Nagel ◽  
J. Nagel
Keyword(s):  
Molecular Mass ◽  
Lethal Effect ◽  
Relative Molecular Mass ◽  
Spleen Cells ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Percoll Gradients ◽  
Fetal Rat Liver ◽  
Liver Fraction

Liver and spleen hematopoietic cell suspensions from 20-day-old-fetal rats were fractionated on Percoll gradients. A granulocyte-rich splenic fraction inhibited CFUe production by cultures of a CFUe-enriched liver fraction, and by cultures of unfractionated liver and spleen hematopoietic cells. Conditioned medium from the spleen cell fraction contained an inhibitor of relative molecular mass, Mr, 25–35 × 10(3). The sensitivity of spleen cells to the inhibitor varied with the age of the fetus from which they were derived (20-day-old less than 18-and 19-day-old). No such age-dependence was found for liver cells. The inhibitor affects cycling CFUe, blocks the lethal effect of AraC, does not appear to be lineage-specific and its influence can be reversed by washing.

Effect of glucose on insulin biosynthesis and β cell ultrastructure in cultured fetal rat pancreas

1984 ◽  
Vol 100 (2) ◽  
pp. 155-160 ◽  
Author(s):  
R. D. G. Milner ◽  
A. Cser ◽  
G. H. Cope
Keyword(s):  
Cell Ultrastructure ◽  
Insulin Biosynthesis ◽  
Cell Nuclei ◽  
Β Cell ◽  
Absolute Volume ◽  
Fetal Rat ◽  
Insulin Granules ◽  
Fetal Rats ◽  
Exocrine Cell

ABSTRACT Pancreatic rudiments from 14-day fetal rats were cultured whole for 8 days in medium containing 5·5 or 16·5 mmol glucose/l (1G or 3G medium). Rudiments grown in 3G medium (3G cells) contained more DNA and insulin than those grown in 1G medium (1G cells) but there was no alteration in the insulin/DNA ratio or the fractional area of the rudiment occupied by insulin-containing cells. Morphometric analysis of ultrastructure revealed that the β cells grown in 3G medium were smaller and had smaller nuclei than those grown in 1G medium. The size of exocrine cell nuclei in 1G or 3G medium was similar. Insulin granules occupied a greater proportion of the cytoplasmic volume in rudiments grown in 3G medium although the mean absolute volume of insulin granules per cell grown in 1G and 3G media was similar. Hence the residual cytoplasmic volume (cell—nucleus and granules) of 3G cells was less than that of 1G cells. Insulin granules from 3G cells had smaller granule sacs and cores than those from 1G cells. It is concluded that glucose stimulates the growth of rat fetal pancreas in vitro and has important effects on β cell ultrastructure. J. Endocr. (1984) 100, 155–160

Stimulation of aromatase activity in the fetal rat testis by cyclic AMP and FSH

1988 ◽  
Vol 118 (3) ◽  
pp. 485-489 ◽  
Author(s):  
J.-P. Weniger ◽  
A. Zeis
Keyword(s):  
Cyclic Amp ◽  
Specific Activity ◽  
Isotopic Dilution ◽  
Aromatase Activity ◽  
Dibutyryl Cyclic Amp ◽  
Rat Testis ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Stimulation Of

ABSTRACT The effect of dibutyryl cyclic AMP and FSH on oestrogen biosynthesis was investigated in testes from 18- to 21-day-old fetal rats cultured in vitro in the presence of tritiated testosterone. Oestrone and oestradiol concentrations were measured by determination of constant specific activity after isotopic dilution. Dibutyryl cyclic AMP and FSH markedly stimulated the conversion of testosterone into both oestrone and oestradiol at all stages studied. Oestradiol synthesis was stimulated by two- to sevenfold, while stimulation of oestrone synthesis was even greater. The results demonstrate that the aromatase enzyme system of the fetal rat testis responds to cyclic AMP and FSH. J. Endocr. (1988) 118, 485–489

Neurothelin: molecular characteristics and developmental regulation in the chick CNS

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 129-140
Author(s):  
B. Schlosshauer
Keyword(s):  
Endothelial Cells ◽  
Membrane Proteins ◽  
Molecular Mass ◽  
Blood Brain Barrier ◽  
Adult Brain ◽  
Brain Barrier ◽  
Relative Molecular Mass ◽  
Brain Neurons ◽  
Blood Brain

Neurothelin has recently been identified as a cell surface protein specific for chick endothelial cells forming the blood-brain barrier. Neurons of the adult brain are essentially devoid of neurothelin. In contrast, neurons of the chick retina, which lack blood vessels and accessory astrocytes, express neurothelin. Here we demonstrate that during chick brain development initially neurothelin is expressed probably in all neuroblasts. With proceeding cytodifferentiation, such as vascularization and gliogenesis, brain neurons become neurothelin negative. Coincidentally the endothelial cells forming the blood-brain barrier start to synthesize neurothelin. In contrast to brain neurons, in retina neurons, neurothelin expression increases by one order of magnitude during the course of histogenesis. Coculturing of chick retinal cells with purified rat astrocytes in vitro results in reduction of neural neurothelin expression as quantified by ELISA. Conversely, disruption of the glia-neuron interactions by culturing brain neurons as individualized cells in vitro leads to a reexpression of neurothelin. This is consistent with the hypothesis that astrocytes inhibit neurothelin expression in neurons. Biochemical characterization classifies neurothelin as an integral membrane protein. Temperature-induced-detergent phase separation, phospholipase C digestion and sodium carbonate treatment were employed to distinguish between integral membrane proteins, lipid-anchored proteins and peripheral membrane proteins. Two-dimensional gel electrophoresis reveals an isoelectric point of about 6.4 for neurothelin. Polysaccharide analysis by glycosidase digestion and lectin binding indicates that neurothelin is highly glycosylated. The relative molecular mass of glycosylated neurothelin is 41 × 10(3), whereas the peptide backbone is only 25 × 10(3). The very strict spatiotemporal regulation of neurothelin expression in the central nervous system suggests that neurothelin fulfils possibly a crucial function such as transport of low relative molecular mass components that are essential for neuronal metabolism. The proposed biological activity of neurothelin might be specifically affected by some of its distinct biochemical features.

Identification of mRNAs encoding low molecular mass heat-shock proteins in maize (Zea mays L.)

1986 ◽  
Vol 28 (6) ◽  
pp. 1106-1114 ◽  
Author(s):  
C. A. B. Rees ◽  
N. C. Hogan ◽  
D. B. Walden ◽  
B. G. Atkinson
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Mass ◽  
Polyclonal Antibodies ◽  
Relative Molecular Mass ◽  
Temperature Heat ◽  
Free Translation ◽  
Shock Proteins

Subjecting 5-day-old maize seedlings to a rapid elevation in growth temperature (heat shock; 25–42 °C) results in a shift in the pattern of protein synthesis in maize plumules from the production of a broad spectrum of proteins to the new and (or) enhanced synthesis of a small number of heat-shock proteins (HSPs). The low relative molecular mass (Mr) HSPs, and more specifically an 18-kDa HSP with four major isoelectric variants, represent the majority of HSP synthesis following cell-free translation of total cellular poly (A)+ RNAs and polyribosomal RNAs extracted from heat-shocked plumules. Immunochemical studies, using polyclonal antibodies raised against the 18-kDa HSPs, show that the 18-kDa HSPs synthesized in vitro share immunochemical properties with HSPs of the same Mr synthesized in vivo by heat-shocked plumules. Furthermore, size fractionation and translation analyses of total cellular poly(A)+ RNAs extracted from heat-shocked plumules demonstrate that poly(A)+ RNAs encoding an 18-kDa HSP(s) have an estimated size of 0.6–0.95 kilobases. The observation that 18-kDa HSPs are absent among the translation products and immunoprecipitates of proteins synthesized in vitro by RNAs extracted from control plumules (25 °C) suggests that the mRNAs encoding 18-kDa HSPs are heat-shock induced.Key words: mRNA, maize, heat shock.

scholarly journals Expression of cytochrome CYP2B1/2 in nonpregnant, pregnant and fetal rats exposed to tobacco smoke.

2000 ◽  
Vol 47 (4) ◽  
pp. 1115-1127 ◽  
Author(s):  
P Czekaj ◽  
A Wiaderkiewicz ◽  
E Florek ◽  
R Wiaderkiewicz
Keyword(s):  
Tobacco Smoke ◽  
Adult Liver ◽  
Pregnant Rats ◽  
Protein Levels ◽  
Pregnant Females ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Brain Microsomes ◽  
Female Wistar Rats ◽  
Fetal Rat Liver

Four-month-old female Wistar rats were exposed for 20 days to tobacco smoke obtained from non-filter cigarettes. During the exposure, concentration of tobacco smoke was monitored indirectly by measuring the CO level (1500 mg/m3 air). The efficacy of exposure was assessed by measuring urine nicotine and cotinine levels. Cigarette smoke did not change total cytochrome P450 and b5 protein levels in any of the organs studied, and most of these organs did not show any changes in the activity of reductases associated with these cytochromes. Following exposure to tobacco smoke, fetal rat liver expressed CYP2B1/2 protein; in newborns (day 1) both liver and lung showed CYP2B1/2 protein expression and very low pentoxyresorufin O-dealkylase activity. Western blot analysis of adult liver, lung, heart, but not of brain microsomes, showed that tobacco smoke induced CYP2B1/2 in both nonpregnant and pregnant rats, though its expression was lower in the livers and hearts of pregnant females. In the rat and human placenta, neither rat CYP2B1/2 nor human CYP2B6 showed basal or tobacco smoke-induced expression at the protein level. This study shows clearly that the expression of CYP2B1/2, which metabolizes nicotine and some drugs and activates carcinogens, is controlled in rats by age-, pregnancy-, and tissue-specific regulatory mechanisms.

Cell Growth and Differentiation of Different Hepatic Cells Isolated From Fetal Rat Liver in Vitro

2006 ◽  
Vol 12 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Henning C. Fiegel ◽  
Helge Bruns ◽  
Christina Höper ◽  
Michael V. Lioznov ◽  
Dietrich Kluth
Keyword(s):  
Cell Growth ◽  
Rat Liver ◽  
Hepatic Cells ◽  
Fetal Rat ◽  
Fetal Rat Liver ◽  
Cell Growth And Differentiation

Respiratory and locomotor patterns generated in the fetal rat brain stem-spinal cord in vitro

1992 ◽  
Vol 67 (4) ◽  
pp. 996-999 ◽  
Author(s):  
J. J. Greer ◽  
J. C. Smith ◽  
J. L. Feldman
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cellular Mechanisms ◽  
Motor Patterns ◽  
Rhythmic Motor ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Locomotor Patterns ◽  
Fetal Rat Brain

An in vitro brain stem-spinal cord preparation from last trimester (E13-E21) fetal rats, which generates rhythmic respiratory and locomotor patterns, is described. These coordinated motor patterns emerge at stages E17-E18. Synchronous rhythmic motor activity, not clearly characterized as respiratory or locomotor, can occur as early as E13. With this preparation, it is now possible to study the ontogenesis of circuits and cellular mechanisms underlying these critical movements.

Glucose-coupled sodium absorption in the developing rat colon

1986 ◽  
Vol 250 (2) ◽  
pp. G221-G226 ◽  
Author(s):  
G. D. Potter ◽  
S. M. Burlingame
Keyword(s):  
Amino Acid ◽  
Dry Weight ◽  
Rat Colon ◽  
Sodium Absorption ◽  
Na Transport ◽  
Fetal Rat ◽  
Fetal Rats ◽  
The Difference ◽  
Developing Rat

The developing mammalian colon is lined by villi and is capable of glucose and amino acid absorption at birth in the rat. Neither the point at which this capacity is lost nor the effect of the capacity for glucose transport on Na absorption has been studied. We have now applied a system for perfusion of the lumen of in vitro segments of colon from 20-day-old fetal rats, and pups between 6 and 8 days old, to measure Na transport and transepithelial potential difference (PD). The lumens of colons from animals at both ages were perfused with solutions containing glucose or mannitol and 22Na. Net Na transport was 164 +/- 37 mu eq X h-1 X g dry weight tissue perfused-1, as determined by the difference between lumen-to-bath and bath-to-lumen flux in fetal rat colons at day 20. Glucose increased the lumen-to-bath flux by 90 +/- 35 mu eq X h-1 X g-1. PD was immediately increased from -1.7 +/- 0.16 to -8.0 +/- 0.96 mV (lumen with respect to bath) by the addition of glucose, and the change in PD was inhibited by 10(-4) M phlorizin. The PD response to glucose was lost at day 2 of life, but the villus epithelium persisted. Amiloride, 10(-4) M, did not alter PD or Na transport at either age. We conclude that the fetal rat colon exhibits glucose-dependent Na flux at birth but that this property is lost by 6-8 days.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Isolation of monoclonal antibodies recognizing rat bone-associated molecules in vitro and in vivo.

1992 ◽  
Vol 40 (9) ◽  
pp. 1339-1352 ◽  
Author(s):  
K Turksen ◽  
U Bhargava ◽  
H K Moe ◽  
J E Aubin
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Myeloma Cell ◽  
Spleen Cells ◽  
Myeloma Cell Line ◽  
Osteogenic Cells ◽  
Fetal Rat ◽  
Osteoblast Lineage

Knowledge of the number and kinds of differentiation steps that characterize cells of the osteoblast lineage is inadequate. To further analyze osteoblast differentiation, we generated a series of monoclonal antibodies (MAb) to osteogenic cells. Spleen cells from mice immunized with whole-cell populations enriched for expression of osteoblast-associated properties or bone formation in vitro were fused with the SP2/0 myeloma cell line. Supernatants from growing hybridomas were screened by indirect immunofluorescence on frozen sections of a portion of 21-day fetal rat heads that included the calvaria bone, periosteum, muscle, fibrous connective tissue, and skin. Six MAb were selected with bone-associated staining and limited ability to label other tissues. Either cell surface or cytoplasmic molecules were recognized by five of the MAb; one recognized a molecule detectable both in the cytoplasm, on the cell surface, and in the extracellular matrix. Of the antibodies selected, one identified both preosteoblasts and osteoblasts and has been found to be against alkaline phosphatase. The others recognized the mature osteoblasts, osteocytes, and chondrocytic cells. The pattern and distribution of the labeling in vivo extended to primary cells and cell lines in vivo. These results support earlier observations on molecules differentially expressed by cells at different stages of the osteoblast lineage and extend the available cell surface and cytoplasmic epitopes identifiable as marker molecules.

Enzyme Activities During Culturing of Fetal Rat Liver

1973 ◽  
Vol 51 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Lorne Kirby ◽  
Peter Hahn
Keyword(s):  
Oleic Acid ◽  
Culture Medium ◽  
Fetal Liver ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Tyrosine Transaminase ◽  
Simple Medium ◽  
Fetal Rat Liver ◽  
Early Rise ◽  
Carnitine Palmitoyltransferases

Liver from fetal rats was cultured in a simple medium. In such cultures tyrosine transaminase (TTA) activity had increased after 20 min and reached twice the initial value within 2 h. Phosphoenolpyruvate earboxykinase (PEPCK) activity decreased during culturing. Incubation of microsomes from fresh fetal liver with dibutyryl cyclic AMP (DcAMP), oleic acid, or acetyl-CoA led to an increase in their TTA activity. It is suggested that the early rise in TTA during culturing is due to release of the enzyme from the microsomal fraction. In contrast to human fetal liver, oleic acid did not induce PEPCK in rat fetal liver cultures. In neither species was there an effect of DcAMP on the amount of fatty acids in the culture medium or on the activities of carnitine acetyl- and carnitine palmitoyltransferases.

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