The objective of the present study is to determine whether methoxychlor (MXC) exposure in adulthood affects rat Leydig cell regeneration and to compare its effects with estradiol (E2). Adult 90-day-old male Sprague-Dawley rats received ethane dimethane sulfonate (EDS) to eliminate the adult Leydig cell population. Subsequently, rats were randomly assigned to four groups and gavaged with corn oi...

Strong overexpression of anti-Müllerian hormone (AMH) in transgenic mice leads to incomplete fetal virilization and decreased serum testosterone in the adult. Conversely, AMH-deficient mice exhibit Leydig cell hyperplasia. To probe the mechanism of action of AMH on Leydig cell steroidogenesis, we have studied the expression of mRNA for steroidogenic proteins in vivo and in vitro and performed a...

Franz Leydig first described the testicular cells in 1850 that now bear his name. For the next 50 yr after their discovery, Leydig cells were the subject of further studies by light microscopy, and diverse speculations were offered about their possible function. In 1903, Pol Bouin and Paul Ancel provided the first substantial evidence that Leydig cells constituted an endocrine gland controlling...

Oestrogen is an important regulator in reproduction. To understand the role of oestrogen receptor 1 (ESR1) in Leydig cells, we investigated the expression of ESR1 in mouse Leydig cells during postnatal development and the effects of oestrogen on steroidogenesis and proliferation of progenitor Leydig cells (PLCs). In Leydig cells, the ESR1 expression was low at birth, increased until postnatal d...

tumour Leydig cells stimulated phosphorylation of five proteins, of 17000, 22000, 24000, 33000 and 57000 Da. Phosphorylation of these proteins coincided with increased pregnenolone production. Phosphorylation of a 33 000-Da protein was lutropindependent in Leydig cells isolated from a Leydig-cell tumour, from immature testes or from mature testes. In tumour Leydig cells this protein was present...

within 3 days after beginning DES treatment and develop a high proportion of malignant interstitial cell tumors when treated with the estrogen for periods of 7 months or longer. Comparable preparations were made from untreated animals of similar ages. The cyt RNA's were then tested for their ability to compete against RNA-3H synthesized on mouse DNA in vitro, using both "presaturation" and simu...

Leydig cells produce testosterone in the testes under the pulsatile control of pituitary luteinizing hormone (LH). cAMP is the intracellular messenger for LH action on steroidogenesis, and pharmacological evidence indicates that the response to LH can be modulated by cyclic nucleotide phosphodiesterases (PDEs). However the types and roles of the PDEs present in Leydig cells have not been fully ...

We recently reported that immature porcine Leydig cells express both somatostatin (SRIF) and SRIF receptor type-2 (sst-2) transcripts. The present study was therefore undertaken to assess whether SRIF might exert autocrine actions on these cells through sst2A receptor, one of the two sst2 isoforms known to exert important neuroendocrine and endocrine functions. Using a polyclonal antibody direc...

The physiological role of multidrug resistance protein 4 (Mrp4, Abcc4) in the testes is unknown. We found that Mrp4 is expressed primarily in mouse and human Leydig cells; however, there is no current evidence that Mrp4 regulates testosterone production. We investigated its role in Leydig cells, where testosterone production is regulated by cAMP, an intracellular messenger formed when the lutei...

Dicyclohexyl phthalate (DCHP) is one of the phthalate plasticizers. The objective of the present study was to investigate the effects of DCHP on fetal Leydig cell distribution and function as well as testis development. Female pregnant Sprague Dawley dams orally received vehicle (corn oil, control) or DCHP (10, 100, and 500 mg/kg/day) from gestational day (GD) 12 to GD 21. At GD 21.5, testicula...