Potent thyrotropic activity of human chorionic gonadotropin variants in terms of 125I incorporation and de novo synthesized thyroid hormone release in human thyroid follicles

1995 ◽  
Vol 80 (2) ◽  
pp. 473-479 ◽  
Author(s):  
K. Yamazaki
Keyword(s):  
Thyroid Hormone ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
De Novo ◽  
Human Thyroid ◽  
Hormone Release ◽  
Thyrotropic Activity

Effect of peptide nicking in the human chorionic gonadotropin β-subunit on stimulation of recombinant human thyroid-stimulating hormone receptors

1994 ◽  
Vol 130 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Masayoshi Yoshimura ◽  
A Eugene Pekary ◽  
Xuan-Ping Pang ◽  
Loretta Berg ◽  
Laurence A Cole ◽  
...  
Keyword(s):  
Los Angeles ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Hormone Receptors ◽  
Thyroid Stimulating Hormone ◽  
Human Thyroid ◽  
Β Subunit ◽  
Trophoblastic Diseases ◽  
Thyrotropic Activity ◽  
Stimulating Hormone

Yoshimura M, Pekary AE, Pang X-P, Berg L, Cole LA, Kardana A, Hershman JM. Effect of peptide nicking in the human chorionic gonadotropin β-subunit on stimulation of recombinant human thyroid-stimulating hormone receptors. Eur J Endocrinol 1994;130:92–6. ISSN 0804–4643 It is now generally accepted that human chorionic gonadotropin (hCG) has thyroid-stimulating activity. Heterologous forms of the hCG molecule occur in the purified preparations extracted from urine of pregnant women and patients with trophoblastic diseases. This work was undertaken to determine the effect of peptide nicking in the hCG-β subunit on its thyrotropic potency. Using Chinese hamster ovary cells expressing functional human thyroid-stimulating hormone (TSH) receptors, we examined the effect of nicked hCG on cyclic AMP (cAMP) production and receptor binding. The effect of human leukocyte elastase (hLE), a nicking enzyme, on standard hCG also was examined in the cAMP assay and on receptor binding. We studied five hCG preparations extracted from the urine of normal pregnancy (CR-127 and P8) and trophoblastic diseases (C2, C5 and M4). Two preparations (C2, 96% nicked and M4, 100% nicked in the β44–49 region) showed about a 1.5-fold potency of standard hCG CR-127, which is also 20% nicked in the same region. Non-nicked hCG (P8) had the weakest potency among all of the samples tested. Treatment of standard hCG with hLE increased the cAMP response about two-fold. Dose-dependent displacement of bovine [125I]TSH by standard hCG and hLE-digested hCG was observed and was almost identical. We have confirmed the increased in vitro thyrotropic activity of hCG nicked in the β-intercysteine loop on recombinant human TSH receptors. These data suggest that peptide heterogeneity of the hCG molecule may modulate the in vivo thyrotropic activity of hCG in pregnant women and patients with trophoblastic diseases. Jerome M Hershman, Endocrinology-W111D, West Los Angeles VA Medical Center, Los Angeles, California 90073, USA

Thyroid-stimulating activity of human chorionic gonadotropin in sera of normal pregnant women

1990 ◽  
Vol 123 (3) ◽  
pp. 277-281 ◽  
Author(s):  
Masayoshi Yoshimura ◽  
Mitsushige Nishikawa ◽  
Masateru Horimoto ◽  
Norio Yoshikawa ◽  
Susumu Sawaragi ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Dependent Manner ◽  
Camp Accumulation ◽  
Serum Samples ◽  
Adenylate Cyclase Activation ◽  
Thyrotropic Activity ◽  
Camp Levels ◽  
Dose Dependent

Abstract. To ascertain the thyrotropic activity of human chorionic gonadotropin in sera of normal pregnant women, we examined the adenylate cyclase activation in the cultured FRTL-5 cells by extracted hCG from 7 normal pregnant women. hCG was extracted from the sera using anti-hCG-β subunit monoclonal antibodycoated microwells, eluted with 2 mol/l guanidine-HCl, and reconstituted with hypotonic Hanks' solution. FRTL-5 cells were precultured in 5H medium, incubated for 2 h with the serum extracts, and the cAMP released into the medium was measured. hCG levels in serum extracts ranged from 1100 to 6800 IU/l; values corresponded to 1.4-19.8% compared with those in the original serum samples. Addition of the extracts to FRTL-5 cells resulted in significant increases in the cAMP accumulation, ranging from 9.8 to 59.0 nmol/l. cAMP levels were also increased in a dose-dependent manner by adding purified hCG as well as crude hCG and hTSH to FRTL-5 cells. These findings suggest that the thyroid gland of normal pregnant women may actually be stimulated by hCG itself.

Desialylated and Deglycosylated Human Chorionic Gonadotropin Are Superagonists of Native Human Chorionic Gonadotropin in Human Thyroid Follicles

Thyroid ◽  
1997 ◽  
Vol 7 (5) ◽  
pp. 783-788 ◽  
Author(s):  
Z. KRAIEM ◽  
N. LAHAT ◽  
O. SADEH ◽  
D.L. BLITHE ◽  
B.C. NISULA
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Human Thyroid

Does human chorionic gonadotropin have human thyrotropic activity in vivo?

1997 ◽  
Vol 11 (3) ◽  
pp. 195-201 ◽  
Author(s):  
R. A. Foulk ◽  
T. J. Musa ◽  
E. D. Schriock ◽  
R. N. Taylor
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Thyrotropic Activity

scholarly journals De Novo-Synthesized Retinoic Acid in Ovarian Antral Follicles Enhances FSH-Mediated Ovarian Follicular Cell Differentiation and Female Fertility

Endocrinology ◽  
2016 ◽  
Vol 157 (5) ◽  
pp. 2160-2172 ◽  
Author(s):  
Tomoko Kawai ◽  
Noriyuki Yanaka ◽  
JoAnne S. Richards ◽  
Masayuki Shimada
Keyword(s):  
Retinoic Acid ◽  
Vitamin A ◽  
Chorionic Gonadotropin ◽  
Granulosa Cells ◽  
Human Chorionic Gonadotropin ◽  
De Novo ◽  
Active Form ◽  
Developmental Competence ◽  
Deficient Diet ◽  
Equine Chorionic Gonadotropin

Abstract Retinoic acid (RA) is the active form of vitamin A and is synthesized from retinol by two key enzymes, alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). As the physiological precursor of RA, retinol impacts female reproductive functions and fertility. The expression of Adh1 and Adh5 as well as Aldh1a1 and Aldh1a7 are significantly increased in the ovaries of mice treated with equine chorionic gonadotropin/FSH. The RA receptor is expressed and localized in granulosa cells and is activated by endogenous RA as indicated by LacZ expression in granulosa cells of RA-responsive transgene-LacZ transgenic mice (RA reporter mice). Coinjection of the ADH inhibitor, 4-methylpyrazole, with equine chorionic gonadotropin significantly decreases the number and developmental competence of oocytes ovulated in response to human chorionic gonadotropin/LH as compared with controls. Injections of RA completely reverse the effects of the inhibitor of ovulation and oocyte development. When mice were fed a retinol-free, vitamin A-deficient diet that significantly reduced the serum levels of retinol, the expression of the LH receptor (Lhcgr) was significantly lower in the ovaries of the vitamin A-deficient mice, and injections of human chorionic gonadotropin failed to induce genes controlling ovulation. These results indicate that ovarian de novo biosynthesis of RA is required for the follicular expression of Lhcgr in granulosa cells and their ability to respond to the ovulatory LH surge.

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