Table Of ContentEN DOCRI NOLOGY
AND PHYSIOLOGY
OF REPRODUCTION
EN DOCRI NOLOGY
AND PHYSIOLOGY
OF REPRODUCTION
Edited by
c.
P. K. Leung
The University of British Columbia
Vancouver, British Columbia, Canada
D. T. Armstrong
University of Western Ontario
London, Ontario, Canada
K. B. Ruf
and
W. H. Moger
Dalhousie University
Halifax, Nova Scotia, Canada
and
H. G. Friesen
University of Manitoba
Winnipeg, Manitoba, Canada
Springer Science+Business Media, LLC
Library of Congress Cataloging In Publication Data
Endocrinology and physiology and reproduction.
Most chapters were presented as plenary lectures or symposium talks at the
1986 30th Congress of the International Union of Physiological Sciences in Van-
couver, B.C.
Includes bibliographies and indexes.
1. Human reproduction—Endocrine aspects—Congresses. 2. Human reproduc-
tion—Congresses. I. Leung, P. C. K. II. International Union of Physiological
Sciences. Congress (30th: 1986: Vancouver, B.C.) [DNLM: 1. Endocrine Glands
—physiology—congresses. 2. Reproduction—congresses. W3 IN84 30th 1986 /
WQ 205 E565 1986]
QP252.E53 1987 612'.6 87-11280
ISBN 978-1-4899-1973-1
ISBN 978-1-4899-1973-1 ISBN 978-1-4899-1971-7 (eBook)
DOI 10.1007/978-1-4899-1971-7
© 1987 Springer Science+Business Media New York
Originally published by Plenum Press, New York in 1987
Softcover reprint of the hardcover 1st edition 1987
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
FOREWORD
Most of the following chapters were presented as plenary lectures or
symposium talks at the 1986 XXXth Congress of the International Union of
Physiological Sciences in Vancouver, B.C. A distinguished international
group of endocrinologists and physiologists have contributed up-to-date
reviews of their particular fields. The early chapters are largely concerned
with the brain and neuroendocrine mechanisms controlling the secretion of
gonadotropin releasing hormone (GnRH) and its action on the anterior pitui
tary gland. Later chapters focus on the gonads themselves and the systemic
and intrinsic hormones influencing the functional cytology of ovarian and
testicular cells. Such comprehensive subjects as sex differentiation,
puberty, placentation and parturition are also discussed authoritatively.
According to Pfaff and Cohen and Arai et al., gonadal steroids,
especially estrogen, exert multiple effects on certain hypothalamic and
preoptic neurons, including growth, protein synthesis and electrical changes,
which promote plasticity and facilitate synaptogenesis. The electrophysio
logy of the hypothalamic GnRH pulse generator in the rhesus monkey is
reviewed more specifically by Knobil. In ovariectomized ewes, Clarke finds
both positive and negative effects of estrogen on hypothalamic release of
GnRH as well as on pituitary responsiveness to the peptide. Flerk6 et al.
and Motta et al. describe mechanisms by which brain and pituitary peptides
can influence hypothalamic function by short and ultrashort feedback circuits
to modulate neural control of pituitary gonadotropin release. An involvement
of the amino acid neurotransmitter y-aminobutyric acid in the control of GnRH
release is also proposed by Wuttke et al. In a study of hypothalamic
biogenic amines, eoen emphasizes the importance of adrenergic nerves in
stimulating GnRH release. Admitting the stimulatory effects, Bergen and
Leung demonstrate that electrical stimulation of the ascending dorsal
midbrain noradrenergic pathway, but not the ventral tract, markedly inhibits
pulsatile LH release in ovariectomized rats, supporting the existence of an
inhibitory noradrenergic system in the modulation of GnRH discharge'. In the
developing female rat approaching puberty, Ojeda et al. describe the inter
play of ovarian estrogen, norepinephrine (NE) and vasoactive intestinal
peptide (VIP) in evoking the release of sufficient GnRH to activate a
proestrous ovulatory LH surge. Estrogen enhances both NE-induced prosta
glandin E2 (PGE2) synthesis and PGE2-induced GnRH release. A protein kinase
C-mediated pathway may also be activated in the hypothalamus and participate
in stimulating GnRH discharge. Millar et al. review structural and
functional characteristics of a recently discovered precursor of GnRH, as
well as the biological activity of non-GnRH synthetic peptide sequences of
the GnRH precursor.
Two chapters by Catt et al. and Naor are concerned with biochemical
mechanisms by which GnRH stimulates LH release. They agree that GnRH first
stimulates a rapid phosphodiester hydrolysis of phosphatidylinositol
v
4,5-biphosphate (PIP2) to inositol-triphosphate (IP3) and diacylglycerol
(DG). 1P3 appears to mobilize cellular Ca2+ while DG activates protein
kinase C. These findings suggest that the LH response to GnRH is mediated by
two intracellular pathways involving Ca2+ and diacylglycerol as second
messengers.
Four chapters are concerned with mechanisms by which local and
circulating hormones influence ovarian cell functions such as steroido
genesis, inhibin secretion, oogenesis and luteolysis. Hsueh and colleagues
have studied extensively the effects of follicle-stimulating hormone on
ovarian granulosa cells in culture and find that the ability of a selected
follicle(s) to become dominant while the majority of follicles become atretic
cannot be explained on the basis of gonadotropin levels alone. Local modula
tory factors are also important. Likewise, Armstrong et al. find that folli
cular steroid biosynthesis is influenced by the local action of the Qvarian
steroids themselves. Steroids represent one of the mechanisms by which
follicular recruitment, growth, atresia, and ovulation may be influenced by
local intraovarian factors. Dekel suggests that meiosis is arrested in the
intrafollicular oocyte by the paracrine transfer of cAMP from the surrounding
cumulus cells, and that the preovulatory surge of LH releases the meiotic
inhibition by breaking down the communication between cumulus and oocyte.
Cumulus-free oocytes resume meiosis and become fertilizable. Sheldrick and
Flint propose that in the sheep oxytocin secreted by the corpus luteum may
contribute to luteolysis by stimulating the release of the ovine luteolysin,
prostaglandin F2Q' The oxytocin receptors in the uterus develop at the
appropriate stage in the estrous cycle, and the short circuit interchange
between corpus luteum and uterus may involve countercurrent distribution of
the peptide and prostaglandin in the ovarian and uterine veins and arteries.
Four chapters focus on the testis and its specialized cells involved in
steroidogenesis and spermatogenesis. Moger et al. review the evidence that
androgen steroidogenesis by the interstitial Leydig cells is influenced by
catecholamines. Pomerantz and Jansz find that disruption of spermatogenesis
by unilateral surgical cryptorchidism induces a hyperresponsiveness of the
Leydig cells in both testes to treatment with LH in vitro. This suggests an
intergonadal transfer of the influence of unilateral aspermatogenesis caused
by the cryptorchidism. According to Bergh and Damber, treatment of the male
rat with hCG/LH induces a rapid rise in testosterone secretion which in turn
causes the local formation of at least two factors influencing testicular
blood vessels, one affecting arteriolar and one increasing venular permeabi
lity by attracting polymorphonuclear leukocytes. The nature and physiolo
gical roles of the factors is unknown. The descent of the testis has been
restudied by Wensing. The essential outgrowth of the gubernaculum appears to
depend on some unknown testicular hormone other than testosterone. However,
there are indications that testosterone plays a major role in the subsequent
regression of the gubernaculum.
Josso et al. describe the factors responsible for sexual differentiation
of the fetus. Genetic and hormonal stimuli including an early anti-Mullerian
hormone secreted by Sertoli cells and testosterone produced subsequently by
Leydig cells induce the male alterations in organs that would otherwise
develop autonomously as female structures. Female organogenesis is disrupted
by exposure to male hormones such as may occur in congenital adrenal hyper
plaSia.
Two placental lactogens have been demonstrated by Duckworth et al. in
the rat. The first, with a mGlecular weight of about 40,000 daltons, peaks
at 12 days of pregnancy and is inhibited by the maternal pituitary. The
second, of about half the molecular weight of the first, appears at about
day 11 and peaks at day 20. Its level is markedly increased by maternal
hypophysectomy or ovariectomy at midpregnancy but strongly suppressed by
fetectomy. The structural relations of these and other lactogen-related
molecules in the rat placenta are under study with genetic coding techniques.
The volume closes with a review of hormonal influences on fetal and
perinatal water metabolism, by Perks and Cassin, and Thorburn's essay on the
comparative physiology of mechanisms controlling the timing of parturition.
The mammalian fetus is usually successful in delaying parturition by suppres
sing excitatory prostaglandin release from the maternal reproductive tract
until its organ systems needed for extrauterine survival are sufficiently
mature. This important process requiring precisely programmed interactions
between fetus and mother exemplifies many of the neuroendocrine mechanisms
encountered repeatedly in the physiology of reproduction.
C.H. Sawyer
Department of Anatomy
University of California
Los Angeles, California, USA 90024
CONTENTS
SECTION I: HYPOTHALAMUS AND OTHER BRAIN AREAS
Estrogen Acting on Hypothalamic Neurons May Have Trophic
Effects on Those Neurons and the Cells on Which They
Synapse 1
D.W. Pfaff and R.S. Cohen
Gonadal Steroid Control of Synaptogenesis in the
Neuroendocrine Brain ••••••• 13
Y. Arai, A. Matsumoto, and M. Nishizuka
The Electrophysiology of the Hypothalamic Gonadotropic
Hormone Releasing Hormone (GnRH) Pulse Generator
in the Rhesus Monkey • • • • . • • • • . • . . • 23
E. Knobil
Ovarian Feedback Regulation of Gonadotropin-Releasing
Hormone Secretion and Action • • . • . • • • • . 27
I.J. Clarke
Short and Ultrashort Feedback Control of Gonadotropin
Secretion • • • • • • • • • 37
B. Flerk6, I. Merchanthaler, and G. Set&16
The Hypothalamo-Pituitary-Gonadal System: Role of
Peptides and Sex Steroids •• . • • 51
M. Motta, D. Dondi, R. Maggi, E. Messi, Z. Zoppi,
M. Zanisi, and F. Piva
Involvement of GABA in the Neuroendocrinology of
Reproduction • . • . • • • • • • • • . • • 65
W. Wuttke, H. Jarry, J. Demling, R. Wolf, and E. DUker
SECTION II: PITUITARY
Hypothalamic Biogenic Amines and the Regulation of
Luteinizing Hormone Release in the Rat .•• 71
C.W. Coen
Dual Action of Norepinephrine in the Control of Gonadotropin
Release •••••••• • • • • • • • • 99
H. Bergen and P.C.K. Leung
Physiological and Biochemical Dissection of Mechanisms
Underlying Puberty • • • • • • • • • • • • • • • •• 113
S.R. Ojeda, H.F. Urbanski, C.E. Ahmed, L. Rogers, and
D. Gonzalez
Biological Activity on Non-GnRH Synthetic Peptide Sequences
of the GnRH Precursor •••••••••••• • • • • 127
R.P. Millar, P.J. Wormald, M.J. Abrahamson,
R.C. deL. Milton, and K. Waligora
Mechanisms of GnRH Action: Interactions between
GnRH-Stimulated Calcium-Phospholipid Pathways
Mediating Gonadotropin Secretion • • • • 135
J.P. Chang, E. McCoy, R.O. Morgan, and K.J. Catt
Phosphoinositide Turnover, Ca2+ Mobilization, and Protein
Kinase C Activation in GnRH Action on Pituitary
Gonadotropin Release • • • • • • • • • • • • • • • • 155
z. Naor
SECTION III: GONADS
The Ovarian Granulosa Cell as a Follicle-Stimulating
Hormone Target Tissue • • • • • • • • • • 163
B. Kessel, X.C. Jia, J.B. Davoren, and A.J.W. Hsueh
Intra-ovarian Actions of Steroids in the Regulation of
Follicular Steroid Biosynthesis • • • • • • 177
D.T. Armstrong, S.A.J. Daniel, and R.E. Gore-Langton
Interaction between the Oocyte and the Granulosa Cells
in the Preovulatory Follicle ••••• 197
N. Dekel
Secretion of Oxytocin by the Corpus Luteum and its Role
in Luteolysis in the Sheep • 211
E.L. Sheldrick and A.P.F. Flint
Catecholamine Effects on Leydig Cell Steroidogenesis:
A Review. • • • • • • • • • • • •••• 221
W.H. Moger, 0.0. Anakwe, and P.R. Murphy
Evidence for Intratesticular Factors Which Mediate the
Response of Leydig Cells to Disruption of
Spermatogenesis • • • • • • • • • 233
D.K. Pomerantz and G.F. Jansz
hCG/LH-Induced Changes in Testicular Blood Flow,
Microcirculation and Vascular Permeability in
Adult Rats •• 243
A. Bergh and J.E. Damber
Morphology of Normal and Abnormal Testicular Descent
and the Regulation of This Process • • 261
C.J.G. Wensing
x
SECTION IV: FETUS AND PLACENTA
Sex Differentiation 273
N. Josso
The Placental Lactogen Gene Family: Structure and
Regulation • • • • • • • • • •••• • • 289
M.L. Duckworth, M.C. Robertson, arid H.G. Friesen
Hormonal Influences on Fetal and Perinatal Water
Metabolism • • 303
A.M. Perks and S. Cassin
The Orchestration of Parturition: Does the Fetus play
the Tune? 331
G.D. Thorburn
Author Index • 355
Subj ect Index 357
xi
