Kisspeptin has an independent and direct effect on the pituitary gland in the mare
| Autor: | Terry M. Nett, Colin M. Clay, Kelly S. Kirkley, Jason E. Bruemmer, Edward L. Squires, Luke A. Sylvester, Brittany Runyan, Christianne Magee |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
endocrine system
medicine.medical_specialty Pituitary gland Population Gonadotropin-releasing hormone Biology Gonadotropic cell Gonadotropin-Releasing Hormone 03 medical and health sciences 0302 clinical medicine Kisspeptin Food Animals Anterior pituitary Internal medicine medicine Animals Horses Small Animals education Receptor Estrous cycle Kisspeptins education.field_of_study 030219 obstetrics & reproductive medicine Equine 0402 animal and dairy science 04 agricultural and veterinary sciences Luteinizing Hormone 040201 dairy & animal science medicine.anatomical_structure Endocrinology Pituitary Gland Female Animal Science and Zoology Follicle Stimulating Hormone hormones hormone substitutes and hormone antagonists |
| Zdroj: | Theriogenology. 157:199-209 |
| ISSN: | 0093-691X |
| DOI: | 10.1016/j.theriogenology.2020.07.031 |
| Popis: | To more clearly understand the equine gonadotrope response to kisspeptin and gonadotropin releasing hormone (GnRH), peripheral LH and FSH were quantified in diestrous mares after treatment with either equine kisspeptide (eKp-10, 0.5 mg iv), GnRH (25 μg iv), or a combination thereof every 4 h for 3 days. The following observations were made: 1) a diminished LH and FSH response to eKp-10 and GnRH was observed by Day 3, but was not different by treatment, 2) a decrease in basal LH concentration was observed from Day 1 to Day 3 for the eKp-10, but not the GnRH treated mares, 3) there was no change in basal FSH with either treatment. Additionally, pre-treatment with GnRH antagonist (antide 1.0 mg iv) eliminated any measurable change in LH after eKp-10 (1.0 mg iv) treatment. Both GnRH and kisspeptin are Gαq/11 coupled receptors, therefore quantifying the rise in intracellular calcium following treatment with cognate ligand allows simultaneous assessment of receptor activation. Direct stimulation of equine primary pituitary cells with GnRH and/or eKp-10 demonstrates three distinct populations of pituitary cells: one population responded to both eKp-10 and GnRH, a second, independent population, responded to only eKp-10, and a third population responded only to GnRH. These populations were confirmed using co-immunofluorescence of hemipituitaries from mares in diestrus. Although the rise in peripheral LH concentration elicited by eKp-10 is dependent on GnRH, this work suggests that kisspeptin also has a specific and direct effect on the equine gonadotrope, independent of GnRH. |
| Databáze: | OpenAIRE |
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