The aim of the present study was to characterize the pituitary gonadotropin-releasing hormone (GnRH) binding site in the rabbit and investigate its possible role in sexual maturation of the female rabbit. A radioligand binding assay was established, and the presence of specific 125I-labelled D-Ala6-des-Gly10-GnRH ethylamide (125I-DAl6EA) binding sites in the anterior pituitary gland of the rabbit was demonstrated. 125I-DAla6EA binding was saturable, specific, displaceable, reversible, correlated with increasing tissue concentrations, and susceptible to physiological manipulation. 125I-DAla6EA binding indicated the presence of two binding sites in the female adult rabbit pituitary: a high affinity, low capacity site (KD = 0.3-0.4 nM; Bmax = 100-200 fmol/mg protein) and a lower affinity, high capacity site (KD = 30 nM; Bmax = 5-8000 fmol/mg protein). Ontogeny of 125I-DAl6EA binding in the female rabbit (40-120 days of age) did not show a correlation between binding site number and serum luteinizing hormone (LH). In addition, the net serum LH response in female rabbits to a subcutaneous injection of DAla6EA (10 ng, 100 ng, and 1 microgram per kilogram body weight) was not significantly different between animals 40, 75, and 120 days of age. This suggests that a decrease in pituitary responsiveness to GnRH is not associated with sexual maturation in the female rabbit. Results indicate that factors other than and (or) in addition to GnRH binding site number, such as postreceptor events, play a role in gonadotropin secretion in the female rabbit.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1139/y92-235 | DOI Listing |
BMJ Open
January 2025
Cancer Research UK Clinical Trials Unit, University of Birmingham, Birmingham, UK.
Introduction: Graft-versus-host disease (GvHD) remains a major complication of allogeneic stem cell transplantation (allo-SCT), affecting 30-70% of patients (representing 800 new patients per year in the UK). The risk is higher in patients undergoing unrelated allo-SCT. About 1 in 10 patients die as a result of GvHD or through complications of its treatment.
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
Johnson & Johnson Vision Care, Inc., Jacksonville, FL, USA.
Purpose: The objective of this three-phase study was to develop a model of mild to moderate evaporative dry eye to be used to evaluate tear film stability endpoints during product development.
Methods: Rabbits were sedated prior to ophthalmic cautery of meibomian gland orifices. The orifices of eyelid meibomian glands were half-cauterized (to yield obstruction of every other meibomian gland orifices), fully cauterized (to yield obstruction of all meibomian gland orifices), or untreated.
Life Med
October 2024
State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China.
The ovary plays a crucial role in the reproductive system of female mammals by producing mature oocytes through folliculogenesis. Non-human model organisms are extensively utilized in research on human ovarian biology, thus necessitating the investigation of conservation and divergence in molecular mechanisms across species. In this study, we employed integrative single-cell analysis of transcriptome and chromatin accessibility to identify the evolutionary conservation and divergence patterns of ovaries among humans, monkeys, mice, rats, and rabbits.
View Article and Find Full Text PDFParasit Vectors
January 2025
Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Avda. Puerta de Hierro S/N, 28040, Madrid, Spain.
Background: In recent years, cases of leishmaniosis have been described in animals housed in captivity in zoos in Spain [Bennett's wallaby (Macropus rufogriseus rufogriseus), orangutan (Pongo pygmaeus pygameus), and European otter (Lutra lutra)]. Some of these zoological parks are in endemic areas for both human and animal leishmaniosis, thus it should be very important to include this zoonosis in the differential diagnosis.
Methods: The study was carried out in two zoological parks in Madrid, Madrid Zoo and Faunia, and analyzed seven meerkats.
Acta Parasitol
January 2025
Centralized Instrumentation Laboratory, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, 600 007, India.
Introduction: Toxocarosis in human beings is currently diagnosed by serological assay based on the detection of antibodies against Toxocara antigens. Toxocara canis larvae do not reach the adult stage in paratenic hosts like humans and mice. Therefore experimental infection in mice, which mimics the biology of human infection, might be relevant to get a better understanding of human toxocarosis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!