scholarly journals Recognition of the Beta-subunit of human chorionic gonadotropin and sub-determinants by target tissue receptors

1978 ◽  
Vol 176 (2) ◽  
pp. 599-602 ◽  
Author(s):  
S Ramakrishnan ◽  
C Das ◽  
G P Talwar
Keyword(s):  
Amino Acid ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Beta Subunit ◽  
Peptide Sequence ◽  
Target Tissue ◽  
Amino Acid Residues ◽  
Testosterone Production ◽  
Tissue Receptors

The beta-subunit of human chorionic gonadotropin, purified immunochemically to eliminate undissociated human chorionic gonadotropin, induced testosterone production by mouse Leydig cells at concentrations 400-fold higher than human chorionic gonadotropin. Steroidogenesis was also stimulated by a synthetic fragment of the beta-subunit of human chorionic gonadotropin conforming to the peptide sequence residues 39–71, whereas peptide sequence residues 39–56 and three C-terminal fragments (residues 115–145, 111–145 and 101–145) failed to cause steroidogenesis. These studies suggest the presence in the beta-subunit of human chorionic gonadotropin of determinants recognized by the tissue receptors, a part of these determinants residing between amino acid residues 57–71.

scholarly journals Cyclooxygenase-2 and Prostaglandin F2α in Syrian Hamster Leydig Cells: Inhibitory Role on Luteinizing Hormone/Human Chorionic Gonadotropin-Stimulated Testosterone Production

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4476-4485 ◽  
Author(s):  
Mónica B. Frungieri ◽  
Silvia I. Gonzalez-Calvar ◽  
Fernanda Parborell ◽  
Martin Albrecht ◽  
Artur Mayerhofer ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Syrian Hamster ◽  
Leydig Cells ◽  
Regulatory Protein ◽  
Hydroxysteroid Dehydrogenase ◽  
Steroidogenic Acute Regulatory Protein ◽  
Testosterone Production ◽  
Cox 2 ◽  
Steroidogenic Acute Regulatory

We have previously found that cyclooxygenase-2 (COX-2), a key enzyme in the biosynthesis of prostaglandins (PGs), is present in the testicular interstitial cells of infertile men, whereas it is absent in human testes with no evident morphological changes or abnormalities. To find an animal model for further investigating COX-2 and its role in testicular steroidogenesis, we screened testes from adult species ranging from mice to monkeys. By using immunohistochemical assays, we found COX-2 expression only in Leydig cells of the reproductively active (peripubertal, pubertal, and adult) seasonal breeder Syrian hamster. COX-2 expression in hamster Leydig cells was confirmed by RT-PCR. In contrast, COX-1 expression was not detected in hamster testes. Because COX-2 expression implies PG synthesis, we investigated the effect of various PGs on testosterone production and found that PGF2α stood out because it significantly reduced human chorionic gonadotropin-stimulated testosterone release from isolated hamster Leydig cells in a dose-dependent manner. This mechanism involves a decreased expression of testicular steroidogenic acute regulatory protein and 17β-hydroxysteroid dehydrogenase. Testicular concentration and content of PGF2α in reproductively active hamsters as well as production of PGF2α from isolated hamster Leydig cells were also determined. Moreover, PGF2α receptors were localized in Leydig cells of hamsters and testicular biopsies from patients with Sertoli cell only and germ arrest syndromes. Thus, in this study, we described a COX-2-initiated pathway that via PGF2α production, PGF2α receptors, steroidogenic acute regulatory protein, and 17β-hydroxysteroid dehydrogenase represents a physiological local inhibitory system of human chorionic gonadotropin-stimulated testosterone production in the Syrian hamster testes.

Human Chorionic Gonadotropin and CA 15-3 Producing Adenocarcinoma

1998 ◽  
Vol 37 (08) ◽  
pp. 297-298 ◽  
Author(s):  
A. Özet ◽  
A. Arpaci ◽  
S. Kömiircü ◽  
G. Üçkaya
Keyword(s):  
Lung Adenocarcinoma ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Carbohydrate Antigen ◽  
Beta Subunit ◽  
Cancer Antigen ◽  
First Report ◽  
Primary Lung Adenocarcinoma ◽  
Adenocarcinoma Of Lung

Summary50 years old man suffering from primary lung adenocarcinoma presented with high levels of both beta subunit human chorionic gonadotropin (βHCG) and cancer antigen 15-3 (CA 15-3) in the absence of elevated carcinoembrionic antigen (CEA), alfa fetoprotein (AFP) and carbohydrate antigen 19-9 (CA 19-9). Although βHCG or CA 15-3 high levels were reported in adenocarcinoma of lung, this is the first report of a patient with high levels of both markers.

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