Browsing by Author "McLachlan, Robert I."
Now showing items 1-19 of 19
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Androgen receptor gene expression in the rat central nervous system: evidence for two mRNA transcripts
Miller, Margaret A.; Dorsa, Daniel M.; Bremner, William J.; McLachlan, Robert I.; Tempel, Bruce L. (Elsevier, 1991-04)Androgen receptor (AR) gene expression in the central nervous system (CNS) and peripheral tissues of male rats was examined using cDNA probes to measure AR mRNA by RNA (Northern) blot analysis and by in situ hybridization. ... -
A comparison of the suppressive effects of testosterone and a potent new gonadotropin-releasing hormone antagonist on gonadotropin and inhibin levels in normal men
Burger, Henry G.; Bremner, William J.; de Kretser, David M.; Rivier, Jean E.; Vale, Wylie W.; Bagatell, Carrie J.; McLachlan, Robert I. (Endocrine Society, 1989-07)GnRH antagonists have been developed in large part because of their potential use as contraceptive agents, particularly in men. Specifically, it was hoped that GnRH antagonists combined with testosterone (T) ... -
Decreased serum inhibin levels in normal elderly men: evidence for a decline in Sertoli cell function with aging
Burger, Henry G.; Dahl, Kristine D.; Bremner, William J.; de Kretser, David M.; Tenover, Joyce S.; McLachlan, Robert I. (Endocrine Society, 1988-09)Compared to young men, normal elderly men have decreased sperm production despite elevated serum gonadotropin levels. To determine whether the seminiferous tubule defect in elderly men includes decreased ... -
Follicle-stimulating hormone is required for quantitatively normal inhibin secretion in men
de Kretser, David M.; Burger, Henry G.; Bremner, William J.; McLachlan, Robert I.; Matsumoto, Alvin M. (Endocrine Society, 1988-12)Inhibin is a glycoprotein hormone produced by the testis and ovary which is postulated to be an important regulator of pituitary FSH secretion. Animal data indicate that inhibin is produced by the Sertoli ... -
Immature spermatids are not prevalent in semen from men who are receiving androgen-based contraceptive regimens
Matsumoto, Alvin M.; Bremner, William J.; McLachlan, Robert I.; Anawalt, Bradley D.; Zhengwei, Yang; Wreford, Nigel G. (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 ... -
The immunoreactive inhibin secretion pattern in the midluteal phase: relationships with luteinizing hormone and progesterone
Clifton, Donald K.; Cohen, Nancy L.; Soules, Michael R.; Bremner, William J.; Nakajima, Steven T.; McLachlan, Robert I. (Blackwell Publishing, 1990-12)With the development of a sensitive radioimmunoassay for inhibin, luteal phase inhibin levels have been noted to parallel progesterone levels and be acutely dependent upon luteinizing hormone (LH) stimulation. ... -
Impairment of Spermatogonial Development and Spermiation after Testosterone-Induced Gonadotropin Suppression in Adult Monkeys (Macaca fascicularis)
Gu, Yi-Qun; Bremner, William J.; Balourdos, Georgia; McLachlan, Robert I.; Robertson, David M.; Wreford, Nigel G.; O'Donnell, Liza; Narula, Anita (The Endocrine Society, 2001-04)Human male hormonal contraceptive regimens do not consistently induce azoospermia, and the basis of this variable response is unclear. This study used nine adult macaque monkeys (Macaca fascicularis) given ... -
The importance of luteinizing hormone in the control of inhibin and progesterone secretion by the human corpus luteum
Rivier, Jean E.; Soules, Michael R.; Vale, Wylie W.; Bremner, William J.; Burger, Henry G.; McLachlan, Robert I.; Cohen, Nancy L. (Endocrine Society, 1989-06)Serum inhibin levels rise markedly during the luteal phase of the human menstrual cycle and are closely correlated with serum progesterone (P) levels, suggesting that the corpus luteum (CL) secretes inhibin. ... -
Luteal phase deficiency: characterization of reproductive hormones over the menstrual cycle
Dahl, Kristine D.; Ek, Marit; Bremner, William J.; Cohen, Nancy L.; Soules, Michael R.; McLachlan, Robert I. (Endocrine Society, 1989-10)The recurrent deficiency of progesterone (P) secretion by the corpus luteum has been associated with infertility and habitual abortion and given the clinical diagnosis of luteal phase deficiency (LPD). There ... -
Novel male hormonal contraceptive combinations: the hormonal and spermatogenic effects of testosterone and levonorgestrel combined with a 5alpha-reductase inhibitor or gonadotropin-releasing hormone antagonist
McLachlan, Robert I.; Bremner, William J.; Amory, John K.; Matthiesson, Kati L.; Ugoni, Antony; Berger, Richard E. (Endocrine Society, 2005-01)We postulated that the addition of a combined types I and II, 5alpha-reductase inhibitor (dutasteride) or long-acting GnRH antagonist (acyline) to combination testosterone plus levonorgestrel treatment may be advantageous ... -
Onset and characteristics of the midcycle surge in bioactive and immunoactive luteinizing hormone secretion in normal women: influence of physiological variations in periovulatory ovarian steroid hormone secretion
Dahl, Kristine D.; Cohen, Nancy L.; Soules, Michael R.; Bremner, William J.; Fritz, Marc A.; McLachlan, Robert I. (Endocrine Society, 1992-08)Limited studies in nonhuman primates suggest that the midcycle LH surge is characterized by distinctly different patterns of bioactive (LH-BIO) and immunoactive (LH-RIA) LH secretion. To further examine the ... -
Quantitative (stereological) study of the normal spermatogenesis in the adult monkey (Macaca fascicularis)
Wreford, Nigel G.; Bremner, William J.; Zhengwei, Yang; McLachlan, Robert I. (American Society of Andrology, 1997-11)Germ cell and Sertoli cell numbers were estimated in six normal adult monkeys (Macaca fascicularis) using a contemporary unbiased and efficient stereological method--the optical disector. The data was used ... -
Recombinant human activin-A stimulates basal FSH and GnRH-stimulated FSH and LH release in the adult male macaque, Macaca fascicularis
Schwall, Ralph; Steiner, Robert A.; Bremner, William J.; Mason, Anthony J.; Schmelzer, Charles H.; McLachlan, Robert I.; Dahl, Kristine D. (Endocrine Society, 1989-11)Activin-A is a homodimer of the beta A inhibin subunit that stimulates FSH secretion by pituitary cells in vitro; however, the physiological relevance of this effect is unknown. We have examined whether ... -
Relationship between serum gonadotropins and spermatogenic suppression in men undergoing steroidal contraceptive treatment
Ugoni, Antony; Bremner, William J.; Pruysers, Enid; Meriggiola, M. Cristina; Anawalt, Bradley D.; Matsumoto, Alvin M.; McLachlan, Robert I.; Robertson, David M. (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 ... -
Serum inhibin concentrations before and during gonadotropin treatment in men with hypogonadotropic hypogonadism: physiological and clinical implications
Snyder, Peter J.; Bremner, William J.; McLachlan, Robert I.; Finkel, David M. (Endocrine Society, 1990-05)We measured by RIA the inhibin concentrations in the sera of 20 men with hypogonadotropic hypogonadism before and during treatment with gonadotropins in order to determine the role of gonadotropins in the ... -
Serum inhibin levels during the periovulatory interval in normal women: relationships with sex steroid and gonadotrophin levels
Bremner, William J.; Dahl, Kristine D.; Soules, Michael R.; McLachlan, Robert I.; Cohen, Nancy L. (Blackwell Publishing, 1990-01)Inhibin is a gonadal glycoprotein believed to be important in the regulation of pituitary FSH secretion and/or to function as a paracrine factor within the ovary and testis. We studied serum levels of inhibin, ... -
Stimulation of Sertoli cell inhibin secretion by the testicular paracrine factor PModS
Bremner, William J.; Skinner, Michael K.; McLachlan, Robert I. (Elsevier, 1989-10)The testicular paracrine factor PModS is produced by peritubular myoid cells under androgen control and modulates Sertoli cell function and differentiation. The observation that luteinizing hormone (LH) ... -
Stimulation of serum inhibin concentrations by gonadotropin-releasing hormone in men with idiopathic hypogonadotropic hypogonadism
Matsumoto, Alvin M.; Bremner, William J.; Tenover, Joyce S.; de Kretser, David M.; Burger, Henry G.; Sheckter, Carol B.; McLachlan, Robert I. (Endocrine Society, 1988-12)Inhibin is a gonadal hormone thought to be important in FSH regulation. We investigated the effects of the hypogonadotropic state and subsequent GnRH-induced increases in gonadotropin levels on inhibin ... -
Variability in sperm suppression during testosterone administration to adult monkeys is related to follicle stimulating hormone suppression and not to intratesticular androgens
Stanton, Peter G.; Bremner, William J.; O'Donnell, Liza; McLachlan, Robert I.; Robertson, David M.; Narula, Anita; Gu, Yi-Qun (Endocrine Society, 2002-07)Sex steroid-based male contraceptive regimens do not induce consistent azoospermia. The reason for this variable response is obscure. We used normal adult male monkeys, Macaca fascicularis (n = 9) as a model of testosterone ...