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Full-Text Articles in Large or Food Animal and Equine Medicine

Kisspeptin Receptor Agonist (Ftm080) Increased Plasma Concentrations Of Luteinizing Hormone In Anestrous Ewes, Brian K. Whitlock, Kelly A. Chameroy, Rebecca R. Payton, Shinya Oishi, Nobutaka Fujii, Joseph A. Daniel Aug 2013

Kisspeptin Receptor Agonist (Ftm080) Increased Plasma Concentrations Of Luteinizing Hormone In Anestrous Ewes, Brian K. Whitlock, Kelly A. Chameroy, Rebecca R. Payton, Shinya Oishi, Nobutaka Fujii, Joseph A. Daniel

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin (KP) and the KP receptor (Kiss1r) are integral to central regulation of the gonadotropic-axis. The demonstration that intravenous infusion of KP can stimulate gonadotropin secretion and ovulation in seasonally anestrous female sheep offers a means of manipulating the reproductive axis. However, KP may be of limited clinical use because of the short circulating half-life. Kiss1r agonists with increased half-life and similar efficacy to KP in vitro potentially may provide beneficial applications in breeding management of many species. However, many of these agonists have not been tested in vivo. This study was designed to test and compare the effects of …


Heifer Estrous Cycle Stage Impacts Luteinizing And Growth Hormone Response To Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Barbara P. Steele, James L. Sartin Oct 2011

Heifer Estrous Cycle Stage Impacts Luteinizing And Growth Hormone Response To Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Barbara P. Steele, James L. Sartin

Animal Science Publications and Other Works

The reproductive neuropeptide, kisspeptin (KP), may have a role in regulation of growth hormone (GH) secretion. Expression of KP and its receptor (Kiss1r) are developmentally and hormonally regulated. This study was conducted to determine the effects of KP on plasma concentrations of luteinizing hormone (LH) and GH in pubertal heifers during different functional reproductive stages. Heifers received a single injection of KP (100 pmole / kg) or saline intravenously during proestrus, estrus, and diestrus, and serial blood samples were collected for 3 hours to determine the response of both LH and GH after treatment. Mean concentrations of LH were increased …


Heifer Estrous Cycle Stage Impacts Luteinizing And Growth Hormone Response To Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Barbara P. Steele, James L. Sartin Oct 2011

Heifer Estrous Cycle Stage Impacts Luteinizing And Growth Hormone Response To Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Barbara P. Steele, James L. Sartin

Brian K Whitlock, PhD, DVM, DACT

The reproductive neuropeptide, kisspeptin (KP), may have a role in regulation of growth hormone (GH) secretion. Expression of KP and its receptor (Kiss1r) are developmentally and hormonally regulated. This study was conducted to determine the effects of KP on plasma concentrations of luteinizing hormone (LH) and GH in pubertal heifers during different functional reproductive stages. Heifers received a single injection of KP (100 pmole / kg) or saline intravenously during proestrus, estrus, and diestrus, and serial blood samples were collected for 3 hours to determine the response of both LH and GH after treatment. Mean concentrations of LH were increased …


Effect Of Kisspeptin On Regulation Of Growth Hormone, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin Sep 2011

Effect Of Kisspeptin On Regulation Of Growth Hormone, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin

Animal Science Publications and Other Works

Kisspeptin ( KP ), a neuroendocrine regulator of reproduction, is hypothesized to be an integrator of metabolism and hormones critical to the regulation of reproduction. Lactation is associated with enhanced growth hormone (GH) responsiveness and reduced fertility. Our study was designed to determine the effects of lactation on KP-stimulated GH and luteinizing hormone (LH) secretion. Five non-lactating and five lactating dairy cows were used in the study. Experiments were conducted with lactating cows at weeks 1, 5 and 11 after parturition. The experimental treatments ( saline and KP [100 and 400 pmol / kg body weight]) were given intravenously and …


Effect Of Kisspeptin On Regulation Of Growth Hormone, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin Sep 2011

Effect Of Kisspeptin On Regulation Of Growth Hormone, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin ( KP ), a neuroendocrine regulator of reproduction, is hypothesized to be an integrator of metabolism and hormones critical to the regulation of reproduction. Lactation is associated with enhanced growth hormone (GH) responsiveness and reduced fertility. Our study was designed to determine the effects of lactation on KP-stimulated GH and luteinizing hormone (LH) secretion. Five non-lactating and five lactating dairy cows were used in the study. Experiments were conducted with lactating cows at weeks 1, 5 and 11 after parturition. The experimental treatments ( saline and KP [100 and 400 pmol / kg body weight]) were given intravenously and …


The Effects Of Lactation And Negative Energy Balance On Kisspeptin-Stimulated Luteinizing Hormone And Growth Hormone In Dairy Cows, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin Nov 2008

The Effects Of Lactation And Negative Energy Balance On Kisspeptin-Stimulated Luteinizing Hormone And Growth Hormone In Dairy Cows, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin

Animal Science Publications and Other Works

Kisspeptin, a neuroendocrine regulator of gonadotropin releasing hormone, is hypothesized to integrate nutrition and hormones critical to metabolism and the regulation of reproduction. Since the negative energy balance of early lactation is associated with reduced fertility via suppression of gonadotropin secretion and enhanced growth hormone (GH) responsiveness, this experiment was designed to determine the effects of stage of lactation and negative energy balance on kisspeptin-10 (Kp-10) stimulated luteinizing hormone (LH) and GH concentrations. Five nonlactating [5.1 ± 0.8 (SEM) years; 577 ± 19 kg body weight (BW)] and five lactating [4.1 ± 0.6 years; 608 ± 11 kg BW] multiparous …


The Effects Of Lactation And Negative Energy Balance On Kisspeptin-Stimulated Luteinizing Hormone And Growth Hormone In Dairy Cows, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin Nov 2008

The Effects Of Lactation And Negative Energy Balance On Kisspeptin-Stimulated Luteinizing Hormone And Growth Hormone In Dairy Cows, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Herris S. Maxwell, Barbara P. Steele, James L. Sartin

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin, a neuroendocrine regulator of gonadotropin releasing hormone, is hypothesized to integrate nutrition and hormones critical to metabolism and the regulation of reproduction. Since the negative energy balance of early lactation is associated with reduced fertility via suppression of gonadotropin secretion and enhanced growth hormone (GH) responsiveness, this experiment was designed to determine the effects of stage of lactation and negative energy balance on kisspeptin-10 (Kp-10) stimulated luteinizing hormone (LH) and GH concentrations. Five nonlactating [5.1 ± 0.8 (SEM) years; 577 ± 19 kg body weight (BW)] and five lactating [4.1 ± 0.6 years; 608 ± 11 kg BW] multiparous …