We have previously described the preparation, purification and partial characterization of recombinant (rec) forms of rat luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In the present study, the special functional features of these hormones were studied further, in vitro and in vivo, and compared with human recLH and recFSH, as well as with human urinary choriongonadotropin (h...

Synthesis and secretion of gonadotropic hormones is a complex process that requires precise regulation of genes encoding for the gonadompin-releasing hormone (GnRH) receptor, the common a-subunit of glycoprotein hormones and the individual P-subunits of the gonadotropins. These genes apparently can be influenced by gonadal steroids, GnRH and other peptide hormones such as activin and inhibin. G...

In birds, as in other vertebrates, reproduction is controlled by the hypothalamo-pituitary-gonadal axis with each component secreting specific neuropeptides or hormones. Until recently, it was believed this axis is exclusively under the stimulatory control of hypothalamic gonadotropin-releasing hormone I (GnRH-I) which in turn, stimulates luteinizing hormone (LH) and follicle stimulating hormon...

BACKGROUND/AIM One of the most common psychiatric disorders in children is attention-deficit/hyperactivity disorder, which is treated extensively by methylphenidate. This study investigates the assessment of the effects of methylphenidate on histopathologic and histomorphometric changes of the testes and serum levels of gonadotropin in mice. MATERIALS AND METHODS In this study, 36 adult male ...

Seasonal breeding is widespread in vertebrates and involves sequential development of the gonads, onset of breeding activities (e.g. cycling in females) and then termination resulting in regression of the reproductive system. Whereas males generally show complete spermatogenesis prior to and after onset of breeding, females of many vertebrate species show only partial ovarian development and ma...

BACKGROUND Human luteinizing hormone (LH) and chorionic gonadotropin (hCG) are glycoprotein hormones regulating development and reproductive functions by acting on the same receptor (LHCGR). We compared the LH and hCG activity in gonadal cells from male mouse in vitro, i.e. primary Leydig cells, which is a common tool used for gonadotropin bioassay. Murine Leydig cells are naturally expressing ...

Spermatogenesis is thought to critically depend on the high intratesticular testosterone (T) levels induced by gonadotropic hormones. Strategies for hormonal male contraception are based on disruption of this regulatory mechanism through blockage of gonadotropin secretion. Although exogenous T or T plus progestin treatments efficiently block gonadotropin secretion and suppress testicular T prod...

Human granulosa cells cultured with calf serum actively proliferated for 18-20 generation and secreted progesterone into the medium; progesterone levels appeared to decline with increase in generation number. Cells cultured under serum-free conditions secreted significant amounts of progesterone and insulin-like growth factor II (IGF-II). The progesterone secretion was enhanced by the addition ...

Given the close relationship among neuroendocrine systems, it is likely that there may be common signals that coordinate the acquisition of adult reproductive function with other homeostatic processes. In this review, we focus on central nervous system insulin-like growth factor-1 (IGF-1) as a signal controlling reproductive function, with possible links to somatic growth, particularly during p...

BACKGROUND Luteinizing hormone (LH) activity in human menopausal gonadotropin (hMG) preparations is derived from human chorionic gonadotropin (hCG) rather than LH. Therefore, we aimed to determine whether there are similarities in the endocrine and follicular profiles of serum and follicular fluid from controlled ovarian stimulation with the recombinant gonadotropins follicle-stimulating hormon...