|
|
||||||||
Biology of Reproduction, Vol 10, 179-198, Copyright © 1974 by Society for the Study of Reproduction
1 Department of Physiology, University of Pittsburgh School of Medicine, Pittsburgh,
Pennsylvania 15261 Binding of tritiated iodinated gonadotropins (LH, HCG, FSH, or prolactin) to
ovarian cells can be measured in ovarian
tissue after in vivo injection of the hormones or after in vitro incubations of slices
or isolated cells or homogenates. Studies
are meaningful only if the labeled hormone
is in a biologically active state. FSH binds
almost exclusively to granulosa cells of
medium size and large follicles. LH and
HCG appear to share the same receptor
and bind primarily to corpus luteum tissue,
thecal cells of large follicles, and to granulosa cells. Thecal tissue isolated from large
preovulatory porcine follicles binds more
HCG compared to thecal tissue isolated
from adjacent small follicles. This difference in receptor number (or affinity) may
explain why only the thecal tissue of large
follicles can respond to the preovulatory
surge of LH by ovulating. Granulosa cells
from large porcine follicles bind 10- to
1000-fold more HCG, compared to the
granulosa cells harvested from small or
medium-sized follicles, indicating that the
maturational state of the follicle determines the number of LH-HCG receptors
on the granulosa cell. This accounts for the
observation that granulosa cells from large
follicles luteinize in culture and after ovulation in vivo, whereas granulosa cells obtained from small follicles do not luteinize
even in the presence of exogenous LH. The
factor(s) controlling induction of the gonadotropin receptors in the thecal as well as
granulosa cells as the follicle matures are
unknown. Stromal tissue binds little or no
gonadotropins. It therefore can be generally accepted that the characteristics of
receptors determine which cellular component of the ovary will respond to gonadotropins. The LH-HCG receptor appears to be
membrane bound and is composed of a
lipid and protein portion. The combination
of both lipid and protein is necessary for
the receptor to bind to the hormone.
The receptor appears to have a molecular
weight of about 69,000.
2 Department of Medicine, New York University School of Medicine, 550 First Avenue,
New York, New York 10016
This article has been cited by other articles:
![]() |
K. L. Britt, P. G. Stanton, M. Misso, E. R. Simpson, and J. K. Findlay The Effects of Estrogen on the Expression of Genes Underlying the Differentiation of Somatic Cells in the Murine Gonad Endocrinology, August 1, 2004; 145(8): 3950 - 3960. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. C. O. Evans and J. E. Fortune Selection of the Dominant Follicle in Cattle Occurs in the Absence of Differences in the Expression of Messenger Ribonucleic Acid for Gonadotropin Receptors Endocrinology, July 1, 1997; 138(7): 2963 - 2971. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Mukherjee, J. E. Casanova, and M. Hunzicker-Dunn Desensitization of the Luteinizing Hormone/Choriogonadotropin Receptor in Ovarian Follicular Membranes Is Inhibited by Catalytically Inactive ARNO+ J. Biol. Chem., February 23, 2001; 276(9): 6524 - 6528. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |