Tissue specific metabolism of 1?,25-dihydroxy-20-epi-vitamin D3 into new metabolites with significant biological activity: Studies in rat osteosarcoma cells (UMR 106 and ROS 17/2.8)

1. The metabolism of radioactive cholecalciferol was studied in control and phenobarbitone-treated rats and pigs. 2. Treatment with phenobarbitone enhanced the appearance in plasma of 25-hydroxycholecalciferol (peak IV on silicic acid chromatography), and of more-polar metabolites (peak V), but not of the most-polar metabolites (peak VI). Peak IV had the chromatographic properties of authentic 25-hydroxycholecalciferol (25-HCC) and had biological activity. 3. There was no effect on the appearance of peaks V and VI in plasma after an injection of radioactive 25-HCC. 4. Treatment with phenobarbitone enhanced the excretion of metabolites of radioactive vitamin D3 in bile. These metabolites were largely water-soluble conjugates of peaks IV, V and VI, which included glucuronides. Peak IV in bile was not identical with 25-HCC. 5. Prolonged treatment with phenobarbitone depleted the tissue radioactivity of rats given radioactive vitamin D3.

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A ribonucleoprotein group with species- and tissue-specific biological activity

Radiation and Environmental Biophysics ◽

10.1007/bf01190585 ◽

1973 ◽

Vol 10 (3) ◽

pp. 257-265 ◽

Cited By ~ 2

Author(s):

G. Wilhelm ◽

J. L. Sellier

Keyword(s):

Biological Activity ◽

Tissue Specific

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Multifunctional Properties of Binary Polyrhodanine Manganese Ferrite Nanohybrids—From the Energy Converters to Biological Activity

Polymers ◽

10.3390/polym12122934 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2934

Author(s):

Emilia Zachanowicz ◽

Magdalena Kulpa-Greszta ◽

Anna Tomaszewska ◽

Małgorzata Gazińska ◽

Monika Marędziak ◽

...

Keyword(s):

Colloidal Suspensions ◽

Specific Cell ◽

Biological Interactions ◽

Manganese Ferrite ◽

Osteosarcoma Cells ◽

Surface Protection ◽

Biologically Relevant ◽

Umr 106 ◽

Relevant Range ◽

And Staphylococcus Aureus

The PRHD@MnFe2O4 binary hybrids have shown a potential for applications in the biomedical field. The polymer cover/shell provides sufficient surface protection of magnetic nanoparticles against adverse effects on the biological systems, e.g., it protects against Fenton’s reactions and the generation of highly toxic radicals. The heating ability of the PRHD@MnFe2O4 was measured as a laser optical density (LOD) dependence either for powders as well as nanohybrid dispersions. Dry hybrids exposed to the action of NIR radiation (808 nm) can effectively convert energy into heat that led to the enormous temperature increase ΔT 170 °C (>190 °C). High concentrated colloidal suspensions (5 mg/mL) can generate ΔT of 42 °C (65 °C). Further optimization of the nanohybrids amount and laser parameters provides the possibility of temperature control within a biologically relevant range. Biological interactions of PRHD@MnFe2O4 hybrids were tested using three specific cell lines: macrophages (RAW 264.7), osteosarcoma cells line (UMR-106), and stromal progenitor cells of adipose tissue (ASCs). It was shown that the cell response was strongly dependent on hybrid concentration. Antimicrobial activity of the proposed composites against Escherichia coli and Staphylococcus aureus was confirmed, showing potential in the exploitation of the fabricated materials in this field.

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Comparative biological activity of 1,25-dihydroxy-vitamin D3 and its 5,6-trans-isomer

Pharmaceutical Chemistry Journal ◽

10.1007/bf00758556 ◽

1986 ◽

Vol 20 (3) ◽

pp. 149-153

Author(s):

M. Yu. Valinietse ◽

V. K. Bauman ◽

D. A. Babarykin ◽

N. A. Bogoslovskii ◽

T. A. Kisel'nikova

Keyword(s):

Biological Activity ◽

Trans Isomer ◽

Vitamin D3 ◽

1,25 Dihydroxy Vitamin D3 ◽

Comparative Biological Activity

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The Molecular Mechanisms Underlying the Regulation of the Biological Activity of Corticotropin-Releasing Hormone Receptors: Implications for Physiology and Pathophysiology

Endocrine Reviews ◽

10.1210/er.2005-0034 ◽

2006 ◽

Vol 27 (3) ◽

pp. 260-286 ◽

Cited By ~ 228

Author(s):

Edward W. Hillhouse ◽

Dimitris K. Grammatopoulos

Keyword(s):

Biological Activity ◽

Molecular Mechanisms ◽

Hormone Receptors ◽

Wide Spectrum ◽

Critical Role ◽

Tissue Specific ◽

Functional Flexibility ◽

Biological Responses ◽

The Central Nervous System ◽

The Impact

The CRH receptor (CRH-R) is a member of the secretin family of G protein-coupled receptors. Wide expression of CRH-Rs in the central nervous system and periphery ensures that their cognate agonists, the family of CRH-like peptides, are capable of exerting a wide spectrum of actions that underpin their critical role in integrating the stress response and coordinating the activity of fundamental physiological functions, such as the regulation of the cardiovascular system, energy balance, and homeostasis. Two types of mammal CRH-R exist, CRH-R1 and CRH-R2, each with unique splicing patterns and remarkably distinct pharmacological properties, but similar signaling properties, probably reflecting their distinct and sometimes contrasting biological functions. The regulation of CRH-R expression and activity is not fully elucidated, and we only now begin to fully understand the impact on mammalian pathophysiology. The focus of this review is the current and evolving understanding of the molecular mechanisms controlling CRH-R biological activity and functional flexibility. This shows notable tissue-specific characteristics, highlighted by their ability to couple to distinct G proteins and activate tissue-specific signaling cascades. The type of activating agonist, receptor, and target cell appears to play a major role in determining the overall signaling and biological responses in health and disease.

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