A comparison of metabolic clearance rates of oestradiol-17 beta in immature and peripubertal female pigs and possible implications for the onset of puberty. 1982

F Elsaesser, and K Stickney, and G Foxcroft

A continuous infusion technique of either [3H]oestradiol-17 beta (E2) or unlabelled E2 was used to investigate suggested differences in the metabolic clearance rate of oestradiol-17 beta (MCR-E2) in immature and peripubertal female pigs. Using the isotope infusion technique, the following values were obtained: 60 day old gilts; MCR-E2 = 2133 +/- 274 (mean +/- SEM) ml/min, MCR-E2/kg BW = 116 +/- 14.5 ml/min kg, and conversion ratio (CR) of E2 to oestrone (E1) = 31.6 +/- 3.7%. The respective values for 160 day old gilts were: MCR-E2 = 3027 +/- 340, MCR-E2/kg BW = 48.5 +/- 4.82, and CR = 15.9 +/- 2.12. Except for a significant difference in the weight related MCR-E2 data for the 60 day old group, similar values were found following infusion of unlabelled E2. The percentage of radioactivity extractable with ether from plasma was 22.6 +/- 3.0% and 27.2 +/- 2.0%. Fifty-seven and 66% of total radioactivity infused was recovered in the urine within 12 h in 60 and 160 day old gilts, respectively. There was no difference in the percentage binding of E2 to plasma proteins as determined by equilibrium dialysis (80%). It is concluded that in addition to an activation of ovarian steroido-genesis during puberty, a gradual maturational decrease in the MCR-E2/kg VW might play a role in raising plasma E2 concentrations and thus in constituting an effective oestrogen feedback signal, which results in the first pre-ovulatory LH-surge.

UI MeSH Term Description Entries
D007263 Infusions, Parenteral The administration of liquid medication, nutrient, or other fluid through some other route than the alimentary canal, usually over minutes or hours, either by gravity flow or often by infusion pumping. Intra-Abdominal Infusions,Intraperitoneal Infusions,Parenteral Infusions,Peritoneal Infusions,Infusion, Intra-Abdominal,Infusion, Intraperitoneal,Infusion, Parenteral,Infusion, Peritoneal,Infusions, Intra-Abdominal,Infusions, Intraperitoneal,Infusions, Peritoneal,Intra Abdominal Infusions,Intra-Abdominal Infusion,Intraperitoneal Infusion,Parenteral Infusion,Peritoneal Infusion
D008657 Metabolic Clearance Rate Volume of biological fluid completely cleared of drug metabolites as measured in unit time. Elimination occurs as a result of metabolic processes in the kidney, liver, saliva, sweat, intestine, heart, brain, or other site. Total Body Clearance Rate,Clearance Rate, Metabolic,Clearance Rates, Metabolic,Metabolic Clearance Rates,Rate, Metabolic Clearance,Rates, Metabolic Clearance
D011485 Protein Binding The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments. Plasma Protein Binding Capacity,Binding, Protein
D011863 Radioimmunoassay Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation. Radioimmunoassays
D011959 Receptors, Estradiol Cytoplasmic proteins that bind estradiol, migrate to the nucleus, and regulate DNA transcription. Estradiol Receptors,Estradiol Receptor,Receptor, Estradiol
D011960 Receptors, Estrogen Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important. Estrogen Receptor,Estrogen Receptors,Estrogen Nuclear Receptor,Estrogen Receptor Type I,Estrogen Receptor Type II,Estrogen Receptors Type I,Estrogen Receptors Type II,Receptor, Estrogen Nuclear,Receptors, Estrogen, Type I,Receptors, Estrogen, Type II,Nuclear Receptor, Estrogen,Receptor, Estrogen
D001798 Blood Proteins Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins. Blood Protein,Plasma Protein,Plasma Proteins,Serum Protein,Serum Proteins,Protein, Blood,Protein, Plasma,Protein, Serum,Proteins, Blood,Proteins, Plasma,Proteins, Serum
D004958 Estradiol The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids. 17 beta-Estradiol,Estradiol-17 beta,Oestradiol,17 beta-Oestradiol,Aerodiol,Delestrogen,Estrace,Estraderm TTS,Estradiol Anhydrous,Estradiol Hemihydrate,Estradiol Hemihydrate, (17 alpha)-Isomer,Estradiol Monohydrate,Estradiol Valerate,Estradiol Valeriante,Estradiol, (+-)-Isomer,Estradiol, (-)-Isomer,Estradiol, (16 alpha,17 alpha)-Isomer,Estradiol, (16 alpha,17 beta)-Isomer,Estradiol, (17-alpha)-Isomer,Estradiol, (8 alpha,17 beta)-(+-)-Isomer,Estradiol, (8 alpha,17 beta)-Isomer,Estradiol, (9 beta,17 alpha)-Isomer,Estradiol, (9 beta,17 beta)-Isomer,Estradiol, Monosodium Salt,Estradiol, Sodium Salt,Estradiol-17 alpha,Estradiol-17beta,Ovocyclin,Progynon-Depot,Progynova,Vivelle,17 beta Estradiol,17 beta Oestradiol,Estradiol 17 alpha,Estradiol 17 beta,Estradiol 17beta,Progynon Depot
D004970 Estrone An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from ANDROSTENEDIONE directly, or from TESTOSTERONE via ESTRADIOL. In humans, it is produced primarily by the cyclic ovaries, PLACENTA, and the ADIPOSE TISSUE of men and postmenopausal women. Folliculin (Hormone),Estrone, (+-)-Isomer,Estrone, (8 alpha)-Isomer,Estrone, (9 beta)-Isomer,Estrovarin,Kestrone,Unigen,Wehgen
D005260 Female Females

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