Medicine and Health Sciences Commons^™

Pubertal And Adult Leydig Cell Function In Mullerian Inhibiting Substance-Deficient Mice, Xiufeng Wu, Ramamani Arumugam, Stephen Baker, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) causes Mullerian duct regression during sexual differentiation and regulates postnatal Leydig cell development. MIS knockout (MIS-KO) mice with targeted deletions of MIS develop Leydig cell hyperplasia, but their circulating androgen concentrations are reportedly unaltered. We compared reproductive hormone profiles, androgen biosynthesis, and the expression of key steroidogenic and metabolic enzymes in MIS-KO and wild-type (WT) mice at puberty (36 d) and sexual maturity (60 d). In pubertal animals, basal testosterone and LH concentrations in plasma were lower in MIS-KO than WT mice, whereas human chorionic gonadotropin-stimulated testosterone concentrations were similar. In adults, basal LH, and both …

Temporal Trends In Serum Concentrations Of Polychlorinated Dioxins, Furans, And Pcbs Among Adult Women Living In Chapaevsk, Russia: A Longitudinal Study From 2000 To 2009, Olivier Humblet, Oleg Sergeyev, Larisa Altshul, Susan A. Korrick, Paige L. Williams, Claude Emond, Linda S. Birnbaum, Jane S. Burns, Mary M. Lee, Boris Revich, Andrey Shelepchikov, Denis Feshin, Russ Hauser

Mary M. Lee

BACKGROUND: The present study assessed the temporal trend in serum concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls (PCBs) among residents of a Russian town where levels of these chemicals are elevated due to prior industrial activity.

METHODS: Two serum samples were collected from eight adult women (in 2000 and 2009), and analyzed with gas chromatography-high-resolution mass spectrometry.

RESULTS: The average total toxic equivalency (TEQ) decreased by 30% (from 36 to 25 pg/g lipid), and the average sum of PCB congeners decreased by 19% (from 291 to 211 ng/g lipid). Total TEQs decreased for seven of the eight women, and the …

Mullerian Inhibiting Substance Recruits Alk3 To Regulate Leydig Cell Differentiation, Xiufeng Wu, Ningning Zhang, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) not only induces Mullerian duct regression during male sexual differentiation but also modulates Leydig cell steroidogenic capacity and differentiation. MIS actions are mediated through a complex of homologous receptors: a type II ligand-binding receptor [MIS type II receptor (MISRII)] and a tissue-specific type I receptor that initiates downstream signaling. The putative MIS type I receptors responsible for Mullerian duct regression are activin A type II receptor, type I [Acvr1/activin receptor-like kinase 2 (ALK2)], ALK3, and ALK6, but the one recruited by MIS in Leydig cells is unknown. To identify whether ALK3 is the specific type I …

A Single Base Pair Mutation Encoding A Premature Stop Codon In The Mis Type Ii Receptor Is Responsible For Canine Persistent Mullerian Duct Syndrome, Wenfang Wu, Shengqin Wan, Pujar Shashikant, Mark Haskins, Donald Schlafer, Mary Lee, Vicki Meyers-Wallen

Mary M. Lee

Mullerian inhibiting substance (MIS), a secreted glycoprotein in the transforming growth factor-beta family of growth factors, mediates regression of the Mullerian ducts during embryonic sex differentiation in males. In persistent Mullerian duct syndrome (PMDS), rather than undergoing involution, the Mullerian ducts persist in males, giving rise to the uterus, fallopian tubes, and upper vagina. Genetic defects in MIS or its receptor (MISRII) have been identified in patients with PMDS. The phenotype in the canine model of PMDS derived from the miniature schnauzer breed is strikingly similar to that of human patients. In this model, PMDS is inherited as a sex-limited …

Infant Formula, Autoimmune Triggers, And Type 1 Diabetes, David Harlan, Mary Lee

Mary M. Lee

No abstract provided.