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Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression
(Endocrine Society, 2005-05)
In previous studies of testicular biopsy tissue from healthy men,
intratesticular testosterone (ITT) has been shown to be much higher than
serum testosterone (T), suggesting that high ITT is needed relative to
serum T for normal spermatogenesis in men. However, the quantitative
relationship between ...
Immature spermatids are not prevalent in semen from men who are receiving androgen-based contraceptive regimens
(Elsevier, 1998-01)
OBJECTIVE: To determine whether immature spermatids increase in semen in
response to hormonal contraceptive treatments. Such a finding would
support the existence of a defect in spermiogenesis, which in turn may
explain the reported variability in sperm output. DESIGN: Semen smears
were obtained ...
Suppression of spermatogenesis in man induced by Nal-Glu gonadotropin releasing hormone antagonist and testosterone enanthate (TE) is maintained by TE alone
(Endocrine Society, 1998-10)
GnRH antagonists plus testosterone (T) suppress LH and FSH levels and
inhibit spermatogenesis to azoospermia or severe oligozoospermia.
High-dose T treatment alone has been shown to be an effective male
contraceptive (contraceptive efficacy rate of 1.4 per 100 person yr).
Combined GnRH antagonist ...
Combined administration of levonorgestrel and testosterone induces more rapid and effective suppression of spermatogenesis than testosterone alone: a promising male contraceptive approach
(Endocrine Society, 1996-02)
Studies using high dose testosterone (T) administration in normal men as a
male contraceptive have resulted in azoospermia rates of only 50-70%.
Previous studies of T and progestogen combinations have shown comparable
rates of azoospermia, but have been uncontrolled or used T in doses less
than ...
Acyline: the first study in humans of a potent, new gonadotropin-releasing hormone antagonist
(Endocrine Society, 2002-07)
Acyline is a novel GnRH antagonist found in animal studies to be a potent
suppressor of circulating gonadotropin and testosterone (T) levels. We
conducted the first study of acyline administration to humans. Eight
healthy, eugonadal young men were administered a series of acyline
injections (0, ...
Desogestrel plus testosterone effectively suppresses spermatogenesis but also causes modest weight gain and high-density lipoprotein suppression
(Elsevier, 2000-10)
OBJECTIVE: To test the hypothesis that oral desogestrel (DSG) plus
testosterone would uniformly and rapidly suppress sperm concentrations in
young men as effectively as levonorgestrel (LNG) plus testosterone and
cause less high-density lipoprotein (HDL) suppression and weight gain.
DESIGN: Single-blind, ...
Exogenous testosterone (T) alone or with finasteride increases physical performance, grip strength, and lean body mass in older men with low serum T
(Endocrine Society, 2005-03)
Testosterone (T) therapy in older men with low serum T levels increases
lean body mass and decreases fat mass. These changes might improve
physical performance and strength; however, it has not been established
whether T therapy improves functional outcome in older men. Moreover,
concerns exist ...
Relationship between serum gonadotropins and spermatogenic suppression in men undergoing steroidal contraceptive treatment
(Endocrine Society, 2004-01)
This study aimed to establish whether the degree of suppression of serum
FSH and LH was related to sperm concentration in three testosterone (T)
plus progestin contraceptive regimens. We measured serum FSH and LH using
a modified, highly sensitive immunofluorometric assay in samples obtained
from ...
Daily testosterone and gonadotropin levels are similar in azoospermic and nonazoospermic normal men administered weekly testosterone: implications for male contraceptive development
(American Society of Andrology, 2001-11)
Weekly intramuscular administration of testosterone esters such as
testosterone enanthate (TE) suppresses gonadotropins and spermatogenesis
and has been studied as a male contraceptive. For unknown reasons,
however, some men fail to achieve azoospermia with such regimens. We
hypothesized that either ...
Intratesticular testosterone concentrations comparable with serum levels are not sufficient to maintain normal sperm production in men receiving a hormonal contraceptive regimen
(American Society of Andrology, 2004-11)
Intratesticular testosterone (ITT) is thought to play a key role in the
control of spermatogenesis in man but is rarely measured. The purposes of
this study were 1) to examine the relationship between intratesticular
fluid and serum testosterone (T) at baseline and during treatment with a
contraceptive ...