The objective of this study was to determine the effects of two different time of GnRH injection after artificial insemination (A.I) (d 6 and d 12) on reproductive performances of Holstein cows during the warm season.  Cows randomly assigned to treatments 1) No GnRH injection (control, n = 300),2) GnRH injection at day 6 after A.I (G6, n=300) and 3) GnRH injection at day 12 after A.I (G12, n=30...

...................................................................................................... ORIGINAL ARTICLES.................................................................................... ABBREVIATIONS........................................................................................... 10 INTRODUCTION...........................................................................

BACKGROUND The onset of sexual maturation at puberty is a unique developmental period from a neuroendocrine perspective in that it is characterized by enhanced FSH secretion and FSH responsiveness to exogenous GnRH (vs. LH) from the gonadotrope, yet the mechanism of these dynamics remains unclear. This study aimed to elucidate this phenomenon using a human disease model of GnRH deficiency (idio...

Three forms of gonadotropin-releasing hormone (GnRH) are isolated and identified here by chemical sequence analysis for one species of tilapia, Oreochromis niloticus, and by HPLC elution position for a second species of tilapia, O. mossambicus. Of the three GnRH forms in O. mossambicus, chicken GnRH-II (cGnRH-II) and sea bream GnRH (sbGnRH) are present in greater abundance in the brain and pitu...

OBJECTIVE To compare the outcomes of protocols for ovarian stimulation with recombinant hCG microdose, with GnRH agonists and antagonists for pituitary suppression. DESIGN Prospective nonrandomized clinical trial. SETTING A private assisted reproduction center. PATIENT(S) We studied 182 patients undergoing intracytoplasmic sperm injection (ICSI) cycles, allocated into two groups: GnRH ago...

This study utilized a newly developed antiserum, specific for lamprey gonadotropin-releasing hormone III (l-GnRH-III), to determine the following: in which regions of the rat hypothalamus the neuronal perikarya producing l-GnRH-III are localized; and whether this peptide, known to selectively induce follicle-stimulating hormone release, is coexpressed in neurons containing mammalian luteinizing...

Gonadotropin-releasing hormone (GnRH) is a neuropeptide hormone responsible for the release of luteinizing hormone (Lh) and follicle-stimulating hormone (Fsh) from the anterior pituitary gland . GnRH have been identified and characterized from the brain of C. catla. A cDNA fragment of 202bp was amplified and GnRH variant has been identified in the form chicken-II-type gonadotropin-releasing hor...

Galanin is colocalized with GnRH, and its expression in these neurons is enhanced at proestrus, a time of activation of GnRH neurons. We tested the hypothesis that the expression of both the GnRH and galanin mRNAs in GnRH neurons decrease during lactation in the rat, a reproductive state characterized by reduced gonadotropin secretion. For double label in situ hybridization, GnRH mRNA was detec...

In this paper a mathematical model is developed based on current biological concepts of the lamprey GnRH-III involved in LH and FSH concentration . The physiologic role played by GnRH-III on gonadotropin secretion in mammalian species is controversial. Although GnRH-III is a weak GnRH agonist, early research in mammalian species suggested that GnRH-III can selectively stimulate the secretion of...

Hypothalamic GnRH (GnRH-I) is known and named for its role in regulating reproductive function in vertebrates by controlling release of gonadotropins from the pituitary. However, another form of GnRH of unknown function (pGlu-His-Trp-Ser-His-Gly-Trp-Tyr-Pro-Gly; GnRH-II) is expressed in the mesencephalon of all vertebrate classes except jawless fish. Here we show with immunocytochemical stainin...