At present, there is no reliable in vitro assembled prepubertal testis-like biomimetic organ culture system designed to assess the functional effects of human gonadotropins on Sertoli and Leydig cells. Spermatogenesis is regulated by endocrine, paracrine, and juxtacrine factors (testicular cross-talk), mainly orchestrated by gonadotropins such as luteinizing hormone (LH) and follicle-stimulatin...

OBJECTIVES Sex steroids such as testosterone and estradiol might protect the brain against Alzheimer's disease (AD). We previously found lower levels of testosterone in men with AD compared with controls. We wanted to assess levels of pituitary gonadotropins that regulate sex steroid levels, to determine whether primary or secondary hypogonadism was responsible for low levels of testosterone in...

The gonadotropin hypothesis proposes that elevated serum gonadotropin levels may increase the risk of epithelial ovarian cancer (EOC). We have studied the effect of treating EOC cell lines (OV207 and OVCAR-3) with FSH or LH. Both gonadotropins activated the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2 (ERK1/2) pathway and increased cell migration that was in...

In the mammalian ovary the follicular fluid contains proteins and peptides which play an important role in growth, development and maturation of oocytes. The gonadotropins and some other factors work synergistically and regulate ovarian functions. In the present study the effect of follicular fluid proteins (FFP) and gonadotropins on progesterone secretion by granulosa cells (GC) from buffalo o...

BACKGROUND Over the last several decades, as a result of an evolution in manufacturing processes, a marked development has been made in the field of gonadotropins for ovarian stimulation. Initially, therapeutic gonadotropins were produced from a simple process of urine extraction and purification; now they are produced via a complex system involving recombinant technology, which yields gonadotr...

Gonadotropin treatment has been used in fertility treatment since the 1930s. First, preparations coming from animals were injected, then, gonadotropins prepared from the pituitary glands of human cadavers. A great step was achieved with the introduction of human menopausal gonadotropin extracted from the urine of postmenopausal women. When cases of Creutzfeld-Jacob disease were recognized after...

Male reproductive function is under the control of both gonadotropins and androgens through a negative feedback loop that involves the hypothalamus, pituitary, and testis known as hypothalamus-pituitary-gonadal axis (HPG). Indeed, estrogens also play an important role in regulating HPG axis but the study on relative contribution to the inhibition of gonadotropins secretion exerted by the amount...

Abstract Study question Following a failed IVF cycle, does adding letrozole for the first 5 days of repeated cycle have any advantage versus repeating same protocol? Summary answer supplementation during ovarian stimulation results in similar cumulative live birth rate (CLBR) with 22% less gonadotropins. What is known already Letrozole an increase intraovarian androgen concentration, which augm...

Hypokalemia produced different effects on steroid sex hormone concentrations in plasma and ovary in the mouse. Estradiol levels were slightly increased, whereas circulating progesterone was markedly decreased in all estrous periods. The preovulatory surge of gonadotropins and the secondary surge of follicle-stimulating hormone (FSH) at estrus were also decreased, but basal levels of both gonado...

Knockout mice lacking the orphan nuclear receptor steroidogenic factor 1 (SF1) exhibit a complex endocrine phenotype that includes adrenal and gonadal agenesis, impaired expression of pituitary gonadotropins, and absence of the ventromedial hypothalamic nucleus (VMH). These multiple defects complicate efforts to delineate primary versus secondary effects of SF1 deficiency in different tissues, ...