Biomaterial Database

[Cholecalciferol hydroxylation in rat hepatocytes under the influence of prednisolone]. 2013

A V Khomenko

Glucocorticoid therapy is accompanied by development of processes typical of steroid osteoporosis. Indirect effects of glucocorticoids on the bone tissue are due to changes in mineral metabolism, which is regulated by vitamin D3. In this connection, we studied the influence of prednisolone on cholecalciferol metabolism. The study has shown that prednisolone action causes impairment of cholecalciferol metabolism in hepatocytes due to inhibiting vitamin D3 25-hydroxylase activity. Microsomal (CYP2R1) and mitochondrial (CYP27A1) isoenzymes of vitamin D3 25-hydroxylase were found to function at different concentrations of the substrate. The relative protein contents of the isoenzymes greatly differed in the liver with the prevalence of CYP27A1 over CYP2R1. Prednisolone administration resulted in the lowering of both mitochondrial and microsomal isoenzymes of vitamin D3 25-hydroxylase. The inhibition of vitamin D3 25-hydroxylating system in hepatocytes contributed to a significant reduction in blood serum 25OHD3.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D011239	Prednisolone	A glucocorticoid with the general properties of the corticosteroids. It is the drug of choice for all conditions in which routine systemic corticosteroid therapy is indicated, except adrenal deficiency states.	Di-Adreson-F,Predate,Predonine,Di Adreson F,DiAdresonF
D002112	Calcifediol	The major circulating metabolite of VITAMIN D3. It is produced in the LIVER and is the best indicator of the body's vitamin D stores. It is effective in the treatment of RICKETS and OSTEOMALACIA, both in azotemic and non-azotemic patients. Calcifediol also has mineralizing properties.	25-Hydroxycholecalciferol,25-Hydroxyvitamin D 3,25-Hydroxycholecalciferol Monohydrate,25-Hydroxyvitamin D3,Calcidiol,Calcifediol Anhydrous,Calcifediol, (3 alpha,5Z,7E)-Isomer,Calcifediol, (3 beta,5E,7E)-Isomer,Calderol,Dedrogyl,Hidroferol,25 Hydroxycholecalciferol,25 Hydroxycholecalciferol Monohydrate,25 Hydroxyvitamin D 3,25 Hydroxyvitamin D3,Anhydrous, Calcifediol,Monohydrate, 25-Hydroxycholecalciferol
D002762	Cholecalciferol	Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.	Vitamin D 3,(3 beta,5Z,7E)-9,10-Secocholesta-5,7,10(19)-trien-3-ol,Calciol,Cholecalciferols,Vitamin D3
D005260	Female		Females
D005938	Glucocorticoids	A group of CORTICOSTEROIDS that affect carbohydrate metabolism (GLUCONEOGENESIS, liver glycogen deposition, elevation of BLOOD SUGAR), inhibit ADRENOCORTICOTROPIC HORMONE secretion, and possess pronounced anti-inflammatory activity. They also play a role in fat and protein metabolism, maintenance of arterial blood pressure, alteration of the connective tissue response to injury, reduction in the number of circulating lymphocytes, and functioning of the central nervous system.	Glucocorticoid,Glucocorticoid Effect,Glucorticoid Effects,Effect, Glucocorticoid,Effects, Glucorticoid
D006900	Hydroxylation	Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)	Hydroxylations