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You searched for subject:(P271). Showing records 1 – 2 of 2 total matches.

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Universiteit Utrecht

1. Walen, M. The efficacy of kisspeptin antagonists p234 and p271 in blocking the response to KP-10 in vivo in the bitch and in vitro using flow-cytometry.

Degree: 2014, Universiteit Utrecht

BACKGROUND: The neuropeptide kisspeptin and its receptor GPR54 play a crucial role in the reproductive function of mammals. Finding an efficient kisspeptin antagonist could be the first step towards a new method for non-surgical contraception in the dog. The aims of this study were to test kisspeptin antagonists 271 and 234 in vitro using flow-cytometry and to test p271 in vivo during different stages of the estrous cycle of the bitch. METHODS: In vitro: Chem-1 cells expressing the human GPR54 receptor were labeled with Fluo-3 AM, a fluorescence indicator for intracellular calcium, and examined by flow-cytometry. A concentration response study of hKP-10 and cKP-10 was designed to test if flow-cytometry is a reliable method for measuring intracellular calcium (as a measure for receptor activation) and to determine the optimal hKP-10 concentration. This data were then used to test the antagonists p234 and p271 in vitro. In vivo: P271 was tested during different stages of the estrous cycle of the bitch. In this study only the results in the follicular phase are discussed. Female dogs received 50 µg/kg/hour p271 by iv infusion for three hour. Two hours after the start of the infusion 0.5 µg/kg cKP-10 was iv administered. Controls received one iv injection of 0.5 µg/kg cKP-10. Blood samples before, during and after the peptide administration were collected for the determination of plasma [LH]. RESULTS: Both human and canine KP-10 gave a typical sigmoidal concentration-response curve in vitro. We found no antagonistic or agonist effect of peptide 234 and 271 in vitro. Furthermore, p271 was not able to reduce basal plasma LH concentrations and the LH response to cKP-10 in vivo in the bitch during follicular phase. CONCLUSION: P271 is probably not a good kisspeptin antagonist for the dog. Flow-cytometric calcium flux assays seem like a reliable method to study kisspeptin receptor activation in vitro. Advisors/Committee Members: Albers-Wolthers, C.H.J..

Subjects/Keywords: Kisspeptin; KP-10; GPR54; antagonist; p234; p271; in vitro; flow-cytometry; in vivo; bitch

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Walen, M. (2014). The efficacy of kisspeptin antagonists p234 and p271 in blocking the response to KP-10 in vivo in the bitch and in vitro using flow-cytometry. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/294313

Chicago Manual of Style (16th Edition):

Walen, M. “The efficacy of kisspeptin antagonists p234 and p271 in blocking the response to KP-10 in vivo in the bitch and in vitro using flow-cytometry.” 2014. Masters Thesis, Universiteit Utrecht. Accessed March 06, 2021. http://dspace.library.uu.nl:8080/handle/1874/294313.

MLA Handbook (7th Edition):

Walen, M. “The efficacy of kisspeptin antagonists p234 and p271 in blocking the response to KP-10 in vivo in the bitch and in vitro using flow-cytometry.” 2014. Web. 06 Mar 2021.

Vancouver:

Walen M. The efficacy of kisspeptin antagonists p234 and p271 in blocking the response to KP-10 in vivo in the bitch and in vitro using flow-cytometry. [Internet] [Masters thesis]. Universiteit Utrecht; 2014. [cited 2021 Mar 06]. Available from: http://dspace.library.uu.nl:8080/handle/1874/294313.

Council of Science Editors:

Walen M. The efficacy of kisspeptin antagonists p234 and p271 in blocking the response to KP-10 in vivo in the bitch and in vitro using flow-cytometry. [Masters Thesis]. Universiteit Utrecht; 2014. Available from: http://dspace.library.uu.nl:8080/handle/1874/294313


Universiteit Utrecht

2. Daniël, J.W. Kisspeptin in vitro: a concentration response study and testing of kisspeptin antagonist P271.

Degree: 2014, Universiteit Utrecht

Kisspeptin is an important regulator of the hypothalamic-pituitary-gonadal axis in mammals. It acts on the GnRH neurons trough the GPR54 receptor initiating GnRH release. The aim of this study is to determine the optimal concentration of kisspeptin-10 to activate the GPR54 receptor in vitro. This data is then used for in vitro testing of the kisspeptin antagonist P271. The GPR54 receptor is a G-protein coupled receptor, which when activated raises the intracellular calcium level. We used a single-cell fluorescence microscopy on Chem-1 cells (expressing the human GPR54 receptor) loaded with the calcium-sensitive fluorescent dye Fura-2. We were unable to create a reproducible concentration-response study, however we found two concentrations of kisspeptin-10 that gave a reproducible peak (10-6M and 10-7M). These concentrations were used to test the antagonist P271. In this study peptide P271 showed agonistic properties and no antagonistic properties. This could be because of the method used in these experiments. Advisors/Committee Members: Albers-Wolthers, C.H.J..

Subjects/Keywords: Kisspeptin; GPR54; Antagonist; P271; in vitro; single-cell fluorescence microscopy; fura-2-AM

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Daniël, J. W. (2014). Kisspeptin in vitro: a concentration response study and testing of kisspeptin antagonist P271. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/289058

Chicago Manual of Style (16th Edition):

Daniël, J W. “Kisspeptin in vitro: a concentration response study and testing of kisspeptin antagonist P271.” 2014. Masters Thesis, Universiteit Utrecht. Accessed March 06, 2021. http://dspace.library.uu.nl:8080/handle/1874/289058.

MLA Handbook (7th Edition):

Daniël, J W. “Kisspeptin in vitro: a concentration response study and testing of kisspeptin antagonist P271.” 2014. Web. 06 Mar 2021.

Vancouver:

Daniël JW. Kisspeptin in vitro: a concentration response study and testing of kisspeptin antagonist P271. [Internet] [Masters thesis]. Universiteit Utrecht; 2014. [cited 2021 Mar 06]. Available from: http://dspace.library.uu.nl:8080/handle/1874/289058.

Council of Science Editors:

Daniël JW. Kisspeptin in vitro: a concentration response study and testing of kisspeptin antagonist P271. [Masters Thesis]. Universiteit Utrecht; 2014. Available from: http://dspace.library.uu.nl:8080/handle/1874/289058

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