scholarly journals Precocious development of uridine diphosphate glucuronosyltransferase activity during organ culture of foetal rat liver in the presence of glucocorticoids

1977 ◽  
Vol 166 (2) ◽  
pp. 249-253 ◽  
Author(s):  
G J Wishart ◽  
M A Goheer ◽  
J E A Leakey ◽  
G J Dutton
Keyword(s):  
Rat Liver ◽  
Defined Medium ◽  
Transferase Activity ◽  
Uridine Diphosphate ◽  
Chemically Defined Medium ◽  
Foetal Rat ◽  
First Time ◽  
Precocious Development ◽  
Stimulation Of

1. Precocious development of mammalian UDP-glucuronosyltransferase (EC 2.4.1.1.7) induced by endogenous compounds of known chemical composition is reported for the first time. 2. This development occurs in cultured explants of foetal rat liver when exposed to corticosteroids possessing a pregn-4′-ene structure and a hydroxy or an oxo group at C-11. 3. Explants from 14-day foetuses cultured for 3 days in a chemically defined medium containing dexamethasone exhibited transferase activities towards o-aminophenol within adult male values. Those liver transferase activities attained in utero by 17 days were still negligible. 4. Evidence from several approaches indicated that the explants required glucocorticoids for expression of the transferase, not for maintenance of viability. 5. Glucocorticoid-dependent stimulation of transferase activity required incorporation of L-[14C]leucine into protein, as judged from the pulsing of cultures with cycloheximide. 6. The relevance of these culture experiments to the situation in vivo is discussed.

scholarly journals Regulation of onset of development of UDP-glucuronosyltransferase activity towards o-aminophenol by glucocorticoids in late-foetal rat liver in utero

1977 ◽  
Vol 168 (3) ◽  
pp. 507-511 ◽  
Author(s):  
G J Wishart ◽  
G J Dutton
Keyword(s):  
Rat Liver ◽  
Alimentary Tract ◽  
Normal Development ◽  
In Utero ◽  
Transferase Activity ◽  
Foetal Rat ◽  
Udp Glucuronosyltransferase ◽  
Foetal Lung ◽  
Precocious Development ◽  
Stimulation Of

1. A precocious development of UDP-glucuronosyltransferase activity (EC 2.4.1.17) towards o-aminophenol is demonstrated in 15-17 day foetal rat liver in utero after dexamethasone administration to the mother. 2. This stimulation of liver transferase activity in utero is directly proportional to the dose of dexamethasone infected. 3. Precocious development of transferase activity in utero can also be effected with the natural glucocorticoid cortisol by multiple injections of large amounts of this hormone into the mother. 4. Transferase activity towards o-aminophenolin foetal lung, kidney and upper alimentary tract can also be precociously stimulated by dexamethasone in 17-day foetuses in utero. 5. Natural development of hepatic transferase activity between days 18 and 20 of gestation is retarded after foetal hypophysectomy by decapitation in utero. 6. Overall glucuronidation of o-aminophenol, as observed in foetal rat liver, is also precociously stimulated by dexamethasone. 7. From this and from evidence previously presented we suggest that glucocorticoids, which are known to increase in rat foetuses between days 17 and 20 of gestation, trigger the normal development in utero of hepatic transferase activity towards o-aminophenol which occurs at that time. We also suggest that these hormones are responsible for the rise in activity of the enzyme in foetal lung, kidney and upper alimentary tract which occurs during the same gestational period.

Growth and differentiation of Tubularia cells in a chemically defined physiological medium

Development ◽  
1968 ◽  
Vol 20 (1) ◽  
pp. 73-80
Author(s):  
Allison L. Burnett ◽  
Faith E. Ruffing ◽  
June Zongker ◽  
Anna Necco
Keyword(s):  
Defined Medium ◽  
Control Mechanisms ◽  
Mucous Cells ◽  
Chemically Defined Medium ◽  
Experimental Animals ◽  
Molecular Weights ◽  
Large Numbers ◽  
High Degree ◽  
I Cells

Although hydroids have proven valuable experimental animals for studies involving polarity and regeneration, they have not been extensively used by chemical embryologists studying control mechanisms in differentiation. Ideally, hydroids should be valuable tools for such a study. Their morpohology is relatively simple since they are diploblastic; their cells achieve a high degree of specialization (cnidoblasts, nerve cells, gland and mucous cells); cell differentiation (and morphogenesis) from a reserve stock of interstitial or i-cells is rapid; and many species can be cultured in large numbers under controlled environmental conditions. Probably one of the reasons for this lack of attention is that no one has succeeded in cloning cells of a particular type in a chemically defined medium. In vivo systems, mainly because of their impermeability to most exogenous materials with molecular weights over 200, have not proven to be especially reliable.

H+ stimulation of cell-mediated bone resorption in tissue culture

1987 ◽  
Vol 253 (1) ◽  
pp. E90-E98 ◽  
Author(s):  
P. Goldhaber ◽  
L. Rabadjija
Keyword(s):  
Tissue Culture ◽  
Calcium Release ◽  
Bone Destruction ◽  
Calcium Content ◽  
Organic Matrix ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
The Media ◽  
Neonatal Mouse Calvaria ◽  
Stimulation Of

The addition of protons in the form of hydrochloric acid (10.5, 17.2, or 26.6 meq/l resulting in an initial media pH of 7.28, 7.15, and 6.94, respectively) to neonatal mouse calvaria maintained in a chemically defined medium in tissue culture for 1 wk increased calcium release in a dose-response fashion. The same amounts of protons added to the media of devitalized calvaria caused no increase in calcium release into the medium. The net cell-mediated calcium release resulting from the addition of 26.6 meq/l of protons amounted to approximately 50% of the initial calvarial calcium content. Hydroxyproline determinations revealed that active resorption was taking place, wherein both mineral and organic matrix are removed simultaneously. Histological examination of the extensively resorbed calvaria demonstrated the presence of numerous osteoclasts in different stages of bone destruction. The addition of indomethacin (100 ng/ml) strongly inhibited the increase in calcium release by added protons, suggesting that prostaglandin synthesis is involved in the phenomenon. The addition of thyrocalcitonin also inhibited proton-induced calcium release, providing additional evidence that the calcium release from cultures exposed to added protons involved osteoclastic activity.

scholarly journals Biotin-mediated protein biosynthesis

1974 ◽  
Vol 140 (3) ◽  
pp. 549-556 ◽  
Author(s):  
R. L. Boeckx ◽  
K. Dakshinamurti
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Rat Liver ◽  
Intestinal Mucosa ◽  
Protein Biosynthesis ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Stimulation Of

The effect of administration of biotin to biotin-deficient rats on protein biosynthesis was studied. Biotin treatment resulted in stimulation by more than twofold of amino acid incorporation into protein, both in vivo and in vitro in rat liver, pancreas, intestinal mucosa and skin. Analysis of the products of amino acid incorporation into liver proteins in vivo and in vitro indicated that the synthesis of some proteins was stimulated more than twofold, but others were not stimulated at all. This indicates a specificity in the stimulation of protein synthesis mediated by biotin.

RNA, PROTEIN AND DNA SYNTHESIS STIMULATED BY TESTOSTERONE, INSULIN AND PROLACTIN IN THE RAT VENTRAL PROSTATE CULTURED IN CHEMICALLY DEFINED MEDIUM

1975 ◽  
Vol 80 (4) ◽  
pp. 761-774 ◽  
Author(s):  
Risto Johansson
Keyword(s):  
Response Times ◽  
Defined Medium ◽  
Ventral Prostate ◽  
Chemically Defined Medium ◽  
Physiological Concentration ◽  
Rat Ventral Prostate ◽  
Organ Type ◽  
High Concentrations ◽  
H Protein

ABSTRACT In an organ type tissue culture of the rat ventral prostate in a chemically defined medium insulin (0.08 IU/ml) stimulated the synthesis of RNA within 6–12 h, the synthesis of protein within 6–12 h and the synthesis of DNA within 2–4 days. Testosterone (10−8 m) stimulated these synthetic processes somewhat more slowly: the synthesis of RNA within 12–24 h, protein within 12–24 h and DNA at 4 days. Rather high concentrations of insulin were needed while testosterone was effective at a physiological concentration. Prolactin (1000 ng/ml) stimulated the synthesis of RNA and protein, but not DNA, when added together with either testosterone or insulin, but was completely ineffective when added alone. The response times resembled those of insulin. The lower concentrations of prolactin were ineffective. Growth hormone, luteinizing hormone and follicle stimulating hormone did not stimulate the synthesis of RNA, protein or DNA even when added with testosterone. The results confirm the findings of the numerous in vivo experiments that the hypophyseal hormone prolactin has a direct effect on the ventral prostate.

Detection of cellulase inhibitor in the wheat bran culture of Aspergillus terreus

1981 ◽  
Vol 27 (12) ◽  
pp. 1334-1340 ◽  
Author(s):  
S. N. Sinha ◽  
B. L. Ghosh ◽  
S. N. Ghose
Keyword(s):  
Molecular Weight ◽  
Wheat Bran ◽  
Filter Paper ◽  
Aspergillus Terreus ◽  
Defined Medium ◽  
Low Molecular Weight ◽  
Chemically Defined Medium ◽  
Plant Origin ◽  
First Time ◽  
Hydrolysis Of

The presence of a cellulase inhibitor in the wheat bran culture of a fungus is reported for the first time. The inhibitor has a low molecular weight and is relatively stable to heat. It is absent from wheat bran and is not produced in a chemically defined medium. Unlike cellulase inhibitors of plant origin, this inhibitor is not a polyphenol. It inhibits the hydrolysis of cotton to a greater degree than that of filter paper or carboxymethylcellulose. In addition to inhibiting Aspergillus terreus cellulase, it also inhibits a variety of commercial cellulases.

scholarly journals Precocious development of glucuronidating and hydroxylating enzymes in chick embryos treated with pituitary grafts

1975 ◽  
Vol 152 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Graham J. Wishart ◽  
Geoffrey J. Dutton
Keyword(s):  
Chorioallantoic Membrane ◽  
Pars Distalis ◽  
Liver And Kidney ◽  
Embryo Liver ◽  
First Time ◽  
Cytochrome P 450 ◽  
Isolated Liver ◽  
Precocious Development ◽  
Nadph Cytochrome C Reductase

1. Initiation of precocious development of UDP-glucuronyltransferase by an endogenous factor is reported for the first time. 2. This development occurs in chick embryo liver and kidney after grafting of the cephalic lobe of chicken pars-distalis pituitary tissue on to the chorioallantoic membrane, and in liver results in a rise in the enzyme activity from virtually zero to ‘adult’ values. Aniline hydroxylase also precociously develops in the liver of grafted embryos, its activity rising from one-third to the full adult value. Specific activities of glucose 6-phosphatase, cytochrome P-450 and NADPH–cytochrome c reductase did not significantly change. 3. The response of the transferase does not require the presence of host pituitary gland nor, apart from 1 day's necessary initiation, the presence of the graft itself. 4. The host becomes competent to respond on the 14th day of incubation; response continues for at least 3 days after removal of the graft, and for 2 days in the isolated liver. Grafting of embryonic pars distalis younger than 17 days does not evoke a response in the host liver. 5. Secretion of the pituitary factor increases suddenly some 24–48h before the naturally developing surge in liver UDP-glucuronyltransferase activity and may be responsible for initiating this rise in vivo. 6. The factor is probably not a growth or luteinizing hormone; its nature and the likelihood of a secondary hormone acting directly on the liver are discussed.

Sign in / Sign up

Export Citation Format

Share Document