Gonadotrophin releasing hormone (GnRH) plays an important regulatory role in the function and growth of human placenta, but its placental expression sites and co-localization with GnRH receptor (GnRH-R) are not well known. GnRH and GnRH-R expression has been found in both placenta and cultured trophoblasts; however, cultured trophoblastic cells very quickly lose GnRH-R message and subsequently ...

Pokeweed antiviral protein (PAP), a 29-kDa ribosome-inactivating protein isolated from the leaves of Phytolacca americana, has potent cytotoxic activity once it enters the cytoplasm of a cell. It is incapable of entering cells by itself. Therefore, our objective was to determine whether a GnRH analog could be used to deliver PAP specifically to cells expressing GnRH receptors. D-Lys(6)-GnRH-Pro...

Gonadotropin-releasing hormone 1 (GnRH1) from the brain controls reproduction in vertebrates via a GnRH-specific receptor in the pituitary; however, other forms of GnRH are found in all species, suggesting additional roles for this family of peptides. GnRH action depends critically on the location of its cognate receptors in the brain. To understand the potential roles of additional GnRH forms,...

Gonadotropin‑releasing hormone (GnRH), or its analogues have been demonstrated to exhibit anti‑proliferative effects on tumour cells in ovarian, endometrial and breast cancer through GnRH‑receptors (GnRH‑R). However, the role of GnRH in nasopharyngeal carcinoma (NPC) remains to be elucidated. In order to investigate the effects of GnRH in NPC, the present study examined the expression of the Gn...

Two forms of gonadotropin-releasing hormone (GnRH), GnRH-I and GnRH-II, are commonly present in mammals. The main hormone controlling reproduction is GnRH-I acting through its receptor (GnRHR-I), whereas the function of GnRH-II is unknown. In primates, it has been suggested that GnRH-II is a specific agonist for the structurally distinct GnRHR-II. Here we compared effects of GnRH-I and GnRH-II ...

Lamprey GnRH-I and lamprey GnRH-III are the only two members of the GnRH family to have substitutions in the sixth position, Glu6 and Asp6, respectively; all other GnRH peptides have Gly in the sixth position suggesting a different conformational structure. Thus, a structure-activity study of lamprey GnRH-I or analogs that were cyclized or with sixth position substitutions were determined in vi...

With the exception of modern mammals, most vertebrate species possess two GnRH genes, GnRH-1 and GnRH-2. In addition, in many teleost fish, there is a third gene called GnRH-3. If the main function of GnRH-1 is unambiguously to stimulate gonadotropin release, the other two GnRH forms still lack clear functions. This is particularly true for the highly conserved GnRH-2 that encodes chicken GnRH-...

Abstract The objective was to compare pregnancy rates (PR) on day 30 and loss between days 60 (PL) after timed artificial insemination (TAI; 0) using 2 synchronization protocols, plasma progesterone 18 in suckled beef cows. Angus cows were randomly assigned either 7-d CoSynch (7-d P + GnRH) or 8-d estradiol (8-d ES) protocols for TAI. On -10, the GnRH treatment group (n=574) received a progeste...

In the nontumorous pituitary, GnRH stimulates the release and synthesis of LH and FSH by gonadotroph cells via the GnRH receptor (GnRH-R). Little is known, however, about expression of GnRH and GnRH-R messenger RNAs (mRNAs) in nontumorous pituitary tissue and in adenomas. To learn more about the distribution and regulatory roles of GnRH and its receptor, we investigated the expression of both G...

The G protein-coupled receptor 54 (GPR54) and its endogenous ligand, kisspeptin, are essential for activation and regulation of the hypothalamic-pituitary-gonadal axis. Analysis of RNA extracts from individually identified hypothalamic GnRH neurons with primers for GnRH, kisspeptin-1, and GPR54 revealed expression of all three gene products. Also, constitutive and GnRH agonist-induced biolumine...