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Journal ArticleDOI

Endogenous corticoids and lung development in the fetal rabbit.

01 Apr 1986-Endocrinology (The Endocrine Society)-Vol. 118, Iss: 4, pp 1622-1629
TL;DR: In the rabbit, increases in plasma cortisol and nuclear receptor-cortisol complex are not temporally associated with the major events of lung development as in other species.
Abstract: Corticosteroid treatment of the fetus, which accelerates lung maturation, may mimic a modulating role of endogenous corticoids in normal development. To investigate this question, we determined the developmental pattern of plasma corticoids and their binding proteins in the rabbit, a commonly used species for studies of lung differentiation. The concentration of cortisol, the most potent glucocorticoid in the rabbit, was maximal at 23 days gestation (1.89 μg/dl), declining to 0.54 μg/dl at term (31 days). Levels of plasma corticosterone were always lower than those of cortisol. The adrenal content of corticoids, expressed per adrenal DNA or g BW, decreased during late gestation. Corticosteroid-binding globulin in fetal plasma decreased strikingly between day 23 (36 fig cortisol bound/dl) and day 31 (4.4 μg/dl; P < 0.001), whereas maternal levels increased about 10-fold during this time. Free cortisol in the fetus increased between 21 and 23 days (0.041 μg/dl) and then decreased somewhat until after day 29...
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Book ChapterDOI
TL;DR: This chapter reviews the historical perspective into the conceptual evolution of 11β-hydroxysteroid dehydrogenase (HSD) from its pedestrian origin as an enzyme that catalyzes reversible inactivation of corticosteroids to its currently more prestigious role as mediator of steroid-receptor interactions.
Abstract: Publisher Summary This chapter reviews the historical perspective into the conceptual evolution of 11β-hydroxysteroid dehydrogenase (HSD) from its pedestrian origin as an enzyme that catalyzes reversible inactivation of corticosteroids to its currently more prestigious role as mediator of steroid-receptor interactions An enzyme responsible for catalyzing the oxidation of cortisol to cortisone is found in rat liver and named “l lβ-hydroxy dehydrogenase” The transformations catalyzed by this enzyme are illustrated in the chapter The catalysis of 11-oxidation and 11-oxoreduction is not uniformly distributed among tissues In liver, 11-oxoreduction is the dominant activity; in most other tissues, it is 11β-hydroxy oxidation The recognition of clinical disorders whose symptomatology could be rationalized as being because of defects in 11-HSD expression It helps in the development of the tools—antibodies, complementary DNA (cDNA)—that facilitate exploration of the enzyme at the molecular level 11-HSD protects cells against the toxic effects of excess corticosteroid The enzyme also serves a conservationist function, as the oxidized form of the steroid can be reduced by 11-oxoreductase to its active reduced form thus contributing to the circulating cortisol, and providing a buffer against the changes in blood level caused by paroxysmal secretion of the adrenal

196 citations

Journal ArticleDOI
TL;DR: It is suggested that a specific interaction between CBG and elastase on the surface of neutrophils may represent a physiologically important event that promotes the delivery of glucocorticoids to these cells at sites of inflammation.

121 citations


Cites background from "Endogenous corticoids and lung deve..."

  • ...Although exogenous glucocorticoids reduce serum CBG levels in several species [46, 56], the levels of both total and free glucocorticoids are very low in both rat [57] and rabbit [52] fetuses at about 70% of gestational age, and are therefore unlikely to initiate a decrease in fetal CBG biosynthesis observed during late gestation in these species....

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  • ...During pregnancy, maternal serum CBG concentrations increase during late gestation in humans [4, 48, 49] and other mammals [2], and have been shown to decline just prior to term in several animal models [50-52]....

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Journal ArticleDOI
TL;DR: Thyroid hormone is a factor responsible for the maturational increase in both active and passive PST NaCl transport, which is demonstrated in 8-wk-old hypothyroid animals and increased to control levels with thyroid treatment.
Abstract: We have recently demonstrated that the rates of both active and passive proximal straight tubule (PST) NaCl transport in neonatal rabbits were less than in adults. In this segment NaCl entry across...

41 citations

OtherDOI
TL;DR: The sections in this article are: Ontogeny of the Hypothalamic-Pituitary-Adrenal Axis, Hyp hypothalamic Paraventricular Nucleus, and Stress Responsiveness in Development.
Abstract: The sections in this article are: 1 Ontogeny of the Hypothalamic-Pituitary-Adrenal Axis 11 Hypothalamic Paraventricular Nucleus 12 Pituitary Function 13 Adrenal Function 14 Glucocorticoid Feedback 15 Hypothalamic-Pituitary-Adrenal Function and Stress Responsiveness in Development 2 Conclusions

36 citations

Journal ArticleDOI
TL;DR: The data indicate that the marked changes in fetal and maternal plasma CBG levels during pregnancy reflect changes in the biosynthesis of the protein rather than alterations in compartmentalization or clearance.
Abstract: The cDNA-deduced primary structure of rabbit corticosteroid- binding globulin (CBG) contains 383 amino acids (mol wt, 42,326), including three cysteine residues and four sites for N-glycosylation. It is primarily the product of a 1.68-kilobase hepatic mRNA, but small amounts of CBG mRNA were also found in maternal lung, spleen, and ovary and fetal kidney. In the fetus, hepatic CBG mRNA concentrations increase markedly after day 11 and were 2- to 5-fold higher than those in maternal liver during days 17–23. They then declined to very low levels at term (31 days). By contrast, maternal hepatic CBG mRNA levels did not increase until day 23; reached a peak at about day 27, and then declined to prepregnancy values by 3 days after delivery. In general, fetal and maternal hepatic CBG mRNA concentrations reflect the corresponding serum CBG levels. Our data, therefore, indicate that the marked changes in fetal and maternal plasma CBG levels during pregnancy reflect changes in the biosynthesis of the protein rather...

31 citations

References
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Journal Article
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.

289,852 citations

Journal ArticleDOI
TL;DR: A 100-fold increase in sensitivity has now been achieved by using tritiated steroids in place of 14C-labeled steroids, by utilizing the CBG's of species other than man, and by using adsorption in Place of dialysis or gel filtration.
Abstract: A method utilizing the steroid-binding properties of corticosteroid-binding globulin (CBG, transcortin) was described in 1963 for the routine determination of corticoids in 1 ml of plasma (J Clin Endocr 23: 293, 1963) and later modified to reduce the time required (J Clin Endocr 24: 919, 1964). A 100-fold increase in sensitivity has now been achieved by using tritiated steroids in place of 14C-labeled steroids, by utilizing the CBG's of species other than man, and by using adsorption in place of dialysis or gel filtration. The use of several insoluble adsorbing agents (Fuller's earth, Florisil, coated charcoal) to separate protein-bound and unbound steroids was investigated and their effects on specificity were studied. The use of these techniques in plasma, urine and cerebrospinal fluid was vindicated. With these methods, cortisol can be measured routinely in 0.01 ml of plasma or 0.1 ml of cerebrospinal fluid, and progesterone in 0.3 ml of plasma. Compound S (11-desoxycortisol), corticosterone, ...

2,059 citations

Journal ArticleDOI
TL;DR: Tests indicated that bromcresol green was not bound by serum globulins and compared with measurements of the albumin fraction of serum which is soluble in 2% (w/v) TCA in ethanol, Satisfactory agreement was obtained.
Abstract: In a convenient and direct method for determination of albumin in human serum, based on the decrease in absorbance of a neutral buffered solution of bromcresol green when albumin combines with the indicator, serum is diluted with a solution of bromcresol green of sufficient concentration to allow essentially linear change of absorbance with albumin concentration. Measurements are made at 615 mµ, where the absorbance of hemoglobin or bilirubin does not interfere. Extremely lipemic, turbid serums may be accurately analyzed. This method has been applied to a number of abnormal serums and compared with measurements of the albumin fraction of serum which is soluble in 2% (w/v) TCA in ethanol. Satisfactory agreement was obtained. Tests indicated that bromcresol green was not bound by serum globulins.

393 citations

Journal ArticleDOI
TL;DR: Application of the method to the estimation of DNA extracted with either 1 n KOH or 1 n PCA from monolayer cell cultures showed that fluorescence could still be developed satisfactorily in the presence of the alkali or acid without neutralizing or drying the sample, thus saving considerable time with no loss of accuracy or reproducibility of the assay.

312 citations