Biomaterial Database

Improved ultrafiltration method for determining unbound cortisol in plasma. 1980

I Jerkunica, and J Sophianopoulos, and D Sgoutas

We describe a modified ultrafiltration method for measuring unbound cortisol in diluted or undiluted plasma or serum. After equilibration at 37 degrees C with purified [3H]cortisol, plasma or serum with or without buffer was placed in the ultrafiltration cell and two successive 0.2-mL fractions of protein-free ultrafiltrate were obtained. Under our conditions, free ligand concentration was independent of flow rate. The second fraction (the first is discarded) was used for determining the proportion of unbound cortisol. The assay is rapid (less than 2 h), practical (no more than 1.5 mL of plasma or serum is necessary), and reproducible (CV: 4.5% within assay and 5.2% in different assays). Samples from normal men and women (blood taken at 0800 and 1600 hours), from pregnant women, and from patients with Cushing's disease and adrenal insufficiency gave results that agreed with those obtained by equilibrium dialysis.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D003480	Cushing Syndrome	A condition caused by prolonged exposure to excess levels of cortisol (HYDROCORTISONE) or other GLUCOCORTICOIDS from endogenous or exogenous sources. It is characterized by upper body OBESITY; OSTEOPOROSIS; HYPERTENSION; DIABETES MELLITUS; HIRSUTISM; AMENORRHEA; and excess body fluid. Endogenous Cushing syndrome or spontaneous hypercortisolism is divided into two groups, those due to an excess of ADRENOCORTICOTROPIN and those that are ACTH-independent.	Cushing's Syndrome,Hypercortisolism,Syndrome, Cushing,Syndrome, Cushing's
D003956	Dialysis	A process of selective diffusion through a membrane. It is usually used to separate low-molecular-weight solutes which diffuse through the membrane from the colloidal and high-molecular-weight solutes which do not. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Dialyses
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006854	Hydrocortisone	The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions.	Cortef,Cortisol,Pregn-4-ene-3,20-dione, 11,17,21-trihydroxy-, (11beta)-,11-Epicortisol,Cortifair,Cortril,Epicortisol,Hydrocortisone, (11 alpha)-Isomer,Hydrocortisone, (9 beta,10 alpha,11 alpha)-Isomer,11 Epicortisol
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D014156	Transcortin	A serpin family member that binds to and transports GLUCOCORTICOIDS in the BLOOD.	Corticosteroid-Binding Globulin,Serpin A6,Corticosteroid Binding Globulin
D014462	Ultrafiltration	The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).