Estrogen Stimulates Growth Hormone and Somatomedin-C in Castrate and Intact Female Baboons
- 1 April 1984
- journal article
- research article
- Published by The Endocrine Society in Journal of Clinical Endocrinology & Metabolism
- Vol. 58 (4), 698-703
- https://doi.org/10.1210/jcem-58-4-698
Abstract
To evaluate the effects of physiological concentrations of estrogen on plasma concentrations of somatomedinC (Sm-C) and GH, 16 chronic castrate female baboons were implanted either with blank Silastic capsules (n = 5) or capsules containing crystalline estradiol (E2; n = 11), which remained in place for 7 days. By day 7, serum E2 levels in treated animals rose into the physiological adult female range (mean ± SEM, 96 ± 9.2 pg/ml) and were greater (P < 0.0005) than those in control animals (27.5 ± 3.4 pg/ml). Sm-C concentrations rose significantly by day 7 in treated animals compared to those in control animals, whether assayed from unprocessed plasma (96% in crease; P < 0.01), plasma pretreated with glycine-HCl (99% increase; P < 0.01), or plasma extracted with acid-ethanol (72% increase; P < 0.02). GH concentrations in these animals were low and were not significantly different in E2-treated and control)animals. To evaluate the effects of pharmacological doses of E2 on Sm-C and GH concentrations, six intact adult female baboons were treated with six daily injections (of 1 mg E2 benzoate in oil. Serum E2 rose to a mean level of 1669 ± 320 pg/xml on day 7. The plasma Sm-C concentration by day 7 was significantly higherthan the pretreatment value whether assayed in untreated plasma (4.3-fold increase; P < 0.01), plasma pretreated with glycine-HCl (2-fold increase; P < 0.01), or plasma extracted with acid-ethanol (1.7-fold increase; P < 0.01). Mean serum GH concentrations rose significantly from 3.3 ng/ml on day 0 to 23.6 ng/ml by day 7 (P < 0.02). Evaluation of the chromatographic profile of native baboon plasma suggested a marked increase in [125I]Sm-C binding to plasma proteinsafter in vivo pharmaco(logical E2 treatment; a broad peak of [125I]Sm-C binding over a size range from that of albumin to γ-globulin was found. These results indicate that estrogen treatment of castrate or intact female baboons with both physiological and pharmacological doses results in an increase in plasma Sm-C concentrations that, at least in pharmacological doses, are mediated through an increase in GH concentrations. Although(pharmacological E2 treatment results in a stimulation of plasma proteins that bind Sm-C, the effects on plasma Sm-C concentrations were found after procedures that diminish interference from circulating binding proteins. These data support the concept that estrogen may play a role in the physiological increase in plasma concentrations of Sm-C associated with normal puberty. (J Clin En-docrinol Metab58: 698,1984)Keywords
This publication has 10 references indexed in Scilit:
- Daytime Pulsatile Growth Hormone Secretion during Childhood and Adolescence*Journal of Clinical Endocrinology & Metabolism, 1982
- Serum Immunoreactive Somatomedin Levels in Normal Adults, Pregnant Women at Term, Children at Various Ages, and Children with Constitutionally Delayed Growth*Journal of Clinical Endocrinology & Metabolism, 1981
- Synergism of Estrogen and Bromergocryptine in the Induction of Luteolysis in Cynomolgus Monkeys(Macaca fascicularis)*Journal of Clinical Endocrinology & Metabolism, 1980
- Inhibition of Access of Bound Somatomedin to Membrane Receptor and Immunobinding Sites: A Comparison of Radioreceptor and Radioimmunoassay of Somatomedin in Native and Acid-Ethanol-Extracted Serum*Journal of Clinical Endocrinology & Metabolism, 1980
- Estradiol treatment of acromegaly Reduction of immunoreactive somatomedin-C and improvement in metabolic statusAmerican Journal Of Medicine, 1980
- Somatomedin A levels in serum from healthy children and from children with growth hormone deficiency or delayed pubertyActa Endocrinologica, 1980
- Induction of Immunoreactive Somatomedin C in Human Serum by Growth Hormone: Dose-Response Relationships and Effect on Chromatographic Profiles*Journal of Clinical Endocrinology & Metabolism, 1980
- Endocrinology in Preadolescents and AdolescentsAmerican Journal of Diseases of Children, 1978
- Estimation of Somatomedin-C Levels in Normals and Patients with Pituitary Disease by RadioimmunoassayJCI Insight, 1977
- Mean 24-hour growth hormone and testosterone concentrations in relation to pubertal growth spurt in boys with normal or delayed pubertyEuropean Journal of Nuclear Medicine and Molecular Imaging, 1976