Follicle-stimulating hormone receptor-mediated uptake of sup 45 Ca sup 2+ by cultured rat Sertoli cells does not require activation of cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding proteins or adenylate cyclase

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Endocrinology; (USA)

DOI:https://doi.org/10.1210/endo-127-2-949· OSTI ID:6530374

Grasso, P; Reichert, Jr, L E ^[1]

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1. Albany Medical College, NY (USA)

We have previously reported that FSH stimulates flux of 45Ca2+ into cultured Sertoli cells from immature rats via voltage-sensitive and voltage-independent calcium channels. In the present study, we show that this effect of FSH does not require cholera toxin (CT)- or pertussis toxin (PT)-sensitive guanine nucleotide binding (G) protein or activation of adenylate cyclase (AC). Significant stimulation of 45Ca2+ influx was observed within 1 min, and maximal response (3.2-fold over basal levels) was achieved within 2 min after exposure to FSH. FSH-stimulated elevations in cellular cAMP paralleled increases in 45Ca2+ uptake, suggesting a possible coupling of AC activation to 45Ca2+ influx. (Bu)2cAMP, however, was not able to enhance 45Ca2+ uptake over basal levels at a final concentration of 1000 microM, although a concentration-related increase in androstenedione conversion to estradiol was evident. Exposure of Sertoli cells to CT (10 ng/ml) consistently stimulated basal levels of androstenedione conversion to estradiol but had no effect on basal levels of 45Ca2+ uptake. Similarly, CT had no effect on FSH-induced 45Ca2+ uptake, but potentiated FSH-stimulated estradiol synthesis. PT (10 ng/ml) augmented basal and FSH-stimulated estradiol secretion without affecting 45Ca2+ influx. The adenosine analog N6-phenylisopropyladenosine, which binds to Gi-coupled adenosine receptors on Sertoli cells, inhibited FSH-stimulated androgen conversion to estradiol in a dose-related (1-1000 nM) manner, but FSH-stimulated 45Ca2+ influx remained unchanged. Our results show that in contrast to FSH-stimulated estradiol synthesis, the flux of 45Ca2+ into Sertoli cells in response to FSH is not mediated either directly or indirectly by CT- or PT-sensitive G protein, nor does it require activation of AC. Our data further suggest that the FSH receptor itself may function as a calcium channel.

• OSTI ID: 6530374
• Journal Information: Endocrinology; (USA), Journal Name: Endocrinology; (USA) Vol. 127:2; ISSN ENDOA; ISSN 0013-7227
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
AMP
ANIMALS
ANTIGENS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
BODY
CALCIUM 45
CALCIUM COMPOUNDS
CALCIUM ISOTOPES
CYCLASES
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTRADIOL
ESTRANES
ESTROGENS
EVEN-ODD NUCLEI
FSH
GONADOTROPINS
GONADS
HORMONES
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LYASES
MALE GENITALS
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
STEROID HORMONES
STEROIDS
SYNTHESIS
TESTES
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
VERTEBRATES