MURPHY weights were recorded at autopsy, between. 1300 and. 1500 h when the animals ... albumin. (Fraction. V)/mlj. Animals. TABLE. 2. Effect of neuraminidase treatment on the ovarian ..... Med. 153:473-475. Chen, Y.-D.I., Shaw, M. J. and.
BIOLOGY
OF REPRODUCTION
26, 422-428
(1982)
Reevaluation
of the Effect of Follicle-Stimulating Hormone on the Steroidogenic Capacity of the Testis: The Effects of Neuraminidase-Treated FSH Preparations W. H. MOGER”2’3 Departments
and
P. R. MURPHY’
of Physiology
and
Obstetrics
and
and
Biophysics’
Gynecology2
Dalbousie University Nova Scotia, Canada
Halifax,
B3H
4H7
ABSTRACT The
ability of FSH treatment to increase the amount of androgen produced by the testis in response to maximum LH stimulation may be an effect of the LH contamination of the FSH preparations. To examine this question, 3 FSH preparations of different potencies and degrees of LH contamination or their neuraminidase-treated derivatives were administered to hypophysectomized immature rats for 5 days. The capacity of the testes to produce androgens in vitro was assessed at the end of the treatment period. Neuraminidase treatment reduces the in vivo activity of ovine and bovine FSH but does not alter the activity of ovine or bovine LH. Neuraminidase treatment of one FSH preparation (NIH-bFSH-B1) did not reduce the ability of this FSH preparation to increase the response of the testisto LH stimulation in vitro. This suggests that the considerable neuraminidase
LH
contamination treatment
of
the
NIH-bFSH-Bi
may
be
responsible
for
its
effect.
However.
of 2 more highly purified FSH preparations (bFSH-199C and NIH-oFSHSi 3) abolished or greatly reduced the ability of these preparations to increase testicular weight and the response to LH in vitro. It isconcluded that the abilityof highly-purified FSH preparations to increase the amount of androgen produced by the testis is due to the FSH activity and not the contaminating LH.
INTRODUCTION
Administration
concentrations
hormone (FSH) preparations sectomized between the ages reportedly
eta!.,
of various follicle-stimulating
increases
the
to rats hypophyof 20 and 71 days
capacity
of the total
in vivo
stimulation
1976;
Selin
Mahesh, 1977).
and
1981)
(Ode!!
Moger,
and
1977;
or in vitro (Chen
Furthermore,
FSH
Swerdloff, Nazain
and
et a!., 1976,
reportedly
augments
capacity of the mature rabbit testis to secrete testosterone in response to maximum the
LH and
stimulation the serum
ministered (hCG)
human correlates
(Johnson and Ewing, testosterone response chorionic positively
1971), to ad-
gonadotropin with
serum
boys
(Sizonenko
These observations are of particular interest for 2 reasons. First, both serum FSH concentrations and the capacity of the testis to secrete androgens increase during pubertal development in the rat, suggesting a causal relationship (Ode!! et al., 1974; Moger and Armstrong, 1974; Purvis et al., 1978; Moger, 1979). Second, the failure to identify FSH receptors on
mass of testicu!ar tissue to produce androgens in response to maximum !uteinizing hormone (LH)
in cryptorchid
1973).
FSH
Leydig cates
cells (Means and Vaitukaitis, that the effect of FSH on
function
is indirect,
recognized
possibly
target for FSH,
1972)
indicell
Leydig
mediated
via
the
the Sertoli cells.
Recognition that chronic administration of small doses of LH also increases the androgen secretory capacity of the testis (5dm and Moger,
1977;
Zipf
et a!., 1978)
led Purvis and
Hansson (1978) to speculate that the observed effect of FSH was due to LH contamination Accepted December 3, 1981. Received November 5, 1981. 3Correspondence: Dr. William H. Moger, Dept. of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
422
of the FSH preparations. Three groups studied this question and arrived at different conclusions. 5dm and Moger (1977) reported that a FSH ination
preparation was
effective
with
very in
little LH
increasing
the
contamandro-
FSH AND
gen
production
TESTICULAR
of the testis
capacity
of
STEROIDOGENESIS
hypo-
preserving
physectomized rats and concluded that FSH was the effective agent. Van Beurden et a!.
rats
increased
isolated
Leydig
cells
response ment
to LH. increases
to
the
secrete
capacity
MATERIALS
in
However, found
FSH
a
similar
preparation
the androgen They
was
response
also reported
FSH-S12
LH
to
FSH tion
et a!.
ineffective
in
of
Leydig
isolated
FSH
which
increasing
with
an
not
affect
the
Neuraminidase
The
re-
tomized
rats
amount arations
of
(1976,
with
doses
of LH equivalent
contamination did not increase
in various androgen
to the
FSH prepproduction
present
tamination of 3 FSH and
with
tion
to
different increase
TABLE
this
FSH
of LH
capacity
of
immature In
the
degrees
the
hypophysectomized ing
reevaluates
LH
con-
addition,
activity
the of
these
rats
of
testes
to
effect of preparations
1. Potencies of gonadotropin
produce destroywhile
FSH
preparations
(Si
of FSH
15.0
NlHbLHB9a