Estradiol processing by pituitary cells in culture: An examination of the influences of various exposures to progesterone

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(90)90216-E· OSTI ID:6230436

Krey, L C; Kamel, F ^[1]

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1. Rockefeller Univ., New York, NY (USA)

Dispersed, estradiol (E{sub 2})-treated pituitary cells were used to examine the cellular mechanisms underlying progesterone (P) suppression of GnRH-stimulated LH and FSH secretion. When cells were exposed to 10{sup {minus}9}M E{sub 2} for 48 h prior to GnRH challenge, P treatment for the last 24 h suppressed gonadotroph responsiveness to GnRH for both LH and FSH secretion. To determine if P acts by blocking E{sub 2} processing and/or uptake, we exposed cells to 2,4,6,7-{sup 3}H-E{sub 2} {plus minus} P and monitored the level and distribution of {sup 3}H-estrogens bound to estrogen receptors salt-extracted from nuclear pellets purified by sucrose density centrifugation. At 1, 4 and 24 h, P had no effect on the level of {sup 3}H-estrogen+receptor complexes or on the distribution of receptor-bound {sup 3}H-E{sub 2}, {sup 3}H-estrone and {sup 3}H-estriol. The results indicate that chronic influences of P to suppress the responsiveness of E{sub 2}-treated gonadotrophs to GnRH cannot be explained by alterations in estrogen receptor occupation as is the case in reproductive tract tissues.

• OSTI ID: 6230436
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 47:14; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
BODY
CELL CULTURES
CHRONIC EXPOSURE
ENDOCRINE GLANDS
ESTRADIOL
ESTRANES
ESTROGENS
FSH
GLANDS
GONADOTROPINS
HORMONES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KETONES
KINETICS
LH
MEMBRANE PROTEINS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY GLAND
PITUITARY HORMONES
PREGNANES
PROGESTERONE
PROTEINS
REACTION KINETICS
RECEPTORS
SECRETION
STEROID HORMONES
STEROIDS
TRACER TECHNIQUES
TRITIUM COMPOUNDS