Diurnal variation of ghrelin, leptin, and adiponectin in Standardbred mares

Gordon, M. E.; McKeever, Kenneth H.

doi:10.2527/2005.83102365x

Cited by 58 publications

(43 citation statements)

References 26 publications

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“…In horses, blood leptin levels appear to fluctuate in a circadian pattern (Piccione et al., 2004; Gordon and McKeever, 2005) or in response to feeding (Gordon and McKeever, 2005, 2006; Van Weyenberg et al., 2008a,b) or exercise (Gordon et al., 2007b). Although fat mass appears to be the primary determinant of blood leptin concentration in the horse (Fitzgerald and McManus, 2000; Buff et al., 2002; Gentry et al., 2002; Kearns et al., 2006), other factors have been shown to modulate circulating levels.…”

Section: Introductionmentioning

confidence: 99%

“…Although fat mass appears to be the primary determinant of blood leptin concentration in the horse (Fitzgerald and McManus, 2000; Buff et al., 2002; Gentry et al., 2002; Kearns et al., 2006), other factors have been shown to modulate circulating levels. Fasting results in a decline in blood leptin concentrations, which may decrease by as much as 50% compared with the fed state after 48 h of feed restriction (McManus and Fitzgerald, 2000; Piccione et al., 2004; Buff et al., 2005; Gordon and McKeever, 2005; Van Weyenberg et al., 2008a,b). Leptin concentrations are reported to exhibit a peak at night and attain a nadir during daylight hours (Piccione et al., 2004; Buff et al., 2005).…”

Section: Introductionmentioning

confidence: 99%

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Variations of plasma leptin in show horses during a work season

Amato

Martin

Dumon

et al. 2011

Animal Physiology Nutrition

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Leptin is an adipocytokine mainly expressed by adipose tissue. Secretion of leptin in healthy animals is closely related to fat mass and metabolic activity. The aim of this study was to investigate plasma leptin variations, in relation to nutritional and exercise parameters in adult show horses during a work season. EDTA-blood samples were taken at rest from 37 Iberian horses. Body weight, body condition score and fat percentage determined by ultrasonic measurement of rump fat thickness were measured. Plasma leptin was determined with a multi-species RIA kit. Linear mixed effects model was used to assess relationship between plasma leptin and other biological parameters. Plasma leptin concentration was <12.6 ng/ml (mean = 2.8 ± 1.6 ng/ml) and was significantly higher during training periods (p < 0.0001) (4.5 ± 1.7 ng/ml) than in show periods (2.0 ± 1.1 ng/ml), despite a significant increase (p < 0.0001) in energy intake. The body weight remained almost constant. The plasma leptin concentrations were significantly affected by exercise (p < 0.0001), body weight (p = 0.04) and BCS (p < 0.0001), but were not affected by percentage of fat. In conclusion, the marked decrease in leptin values observed during a period of intense (i.e. excessive) exercise could result from an adaptation to cumulative alterations in energy balance, to exercise per se or to a combination of both.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Variations of plasma leptin in show horses during a work season

Amato

Martin

Dumon

et al. 2011

Animal Physiology Nutrition

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“…These animals exhibit a two-fold increase in ghrelin levels during a 48 hour fast, but show no changes in circulating ghrelin levels during a 6 week period of food restriction (Tups et al, 2004). In diurnal mammals, ghrelin levels are highest during nocturnal fasting (Cummings, 2006; Gordon et al, 2005). In rats and humans, plasma ghrelin levels are increased before a meal and decrease immediately following a meal (Beck et al, 2003; Toshinai et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Plasma ghrelin concentrations change with physiological state in a sciurid hibernator (Spermophilus lateralis)

Healy

Ostrom

Wilkerson

et al. 2010

General and Comparative Endocrinology

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Ghrelin is a recently discovered hormone which has profound effects on food intake and lipogenesis in mammals. In all mammals studied thus far, plasma ghrelin concentrations are increased before a meal and decrease immediately following a meal; ghrelin levels increase with fasting. The goldenmantled ground squirrel Spermophilus lateralis (also known as Callospermophilus lateralis (see Helgen et al., 2009)) is a diurnal hibernator which has a robust annual cycle of body mass gain and loss that is primarily controlled by food intake. We hypothesized that in spring, summer, and autumn, the endogenous ghrelin concentrations of hibernators would be similar to those of non-hibernators, but that during the winter hibernation season, plasma ghrelin concentrations would be low or undetectable. We found that peripherally injected ghrelin significantly increased food intake in June. Plasma ghrelin concentrations were significantly increased through 5 days of fasting during a shortterm fast in summer. Over a 24 hour period, ghrelin concentrations increased at night and decreased during the day with drops corresponding to times when squirrels were eating. In January, ghrelin concentrations are low but measurable even while animals are at low body temperature (Tb). The reason for the persistence of ghrelin in plasma at this time is unclear, but circulating ghrelin in hibernators may be involved with the control of sleep in these animals. This is the first report of ghrelin concentrations in a non-photoperiodic hibernator. We suggest that ghrelin may be important for the regulation of food intake and the body mass cycle in mammals that hibernate.

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“…The total ghrelin plasma concentration was determined using the RIA kit (Linco Research, St. Louis, USA) demonstrating the sensitivity at the level of 93 pg/ml. The results were expressed as human equivalents of immunoreactive ghrelin (Gordon and McKeever 2005). Samples were run in duplicate and counted for one minute in a gamma counter (Packard Instruments Company, USA).…”

Section: Analysesmentioning

confidence: 99%

“…This hormone increases appetite, food intake, energy balance and as a result, body weight (Hayashida et al 2001, Gil-Campos et al 2006. In cases of low-caloric diets or chronic exercise the plasma ghrelin level in horses increased (Gordon and McKeever 2005). Moreover, in states of satiety or after glucose challenge the concentration of this peptide decreased .…”

Section: Introductionmentioning

confidence: 99%

The effect of interval versus continuous exercise on plasma leptin and ghrelin concentration in young trotters

Kowalik¹,

Kędzierski²

2011

Polish Journal of Veterinary Sciences

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The effect of interval vs. continuous exercise on plasma leptin and ghrelin concentration in young Standardbred horses was studied. The experiment was conducted on 27 trotters, in the age between 2 and 3 years. They were divided into two groups according to the type of exercise. Blood samples were collected through jugular venipuncture in the following experimental conditions: at rest, immediately after exercise and 30 minutes after the end of the effort. Plasma leptin and ghrelin concentrations were determined using RIA tests. The continuous exercise induced an increase in plasma leptin concentration whereas the interval type of exercise did not influence the level of this hormone (3.47 ± 0.78 vs. 4.07 ± 0.94 and 2.31 ± 0.15 vs. 2.36 ± 0.21 ng/mL, respectively). The plasma ghrelin concentration measured after the continuous exercise, significantly increased (720 ± 27.4 vs. 814 ± 13.8; p ≤ 0.05) whereas concentration of this hormone assessed after the interval exercise, significantly dropped (982 ± 56.5 vs. 842 ± 35.6 pg/mL; p ≤ 0.05). The changes in plasma ghrelin concentration measured after the end of the effort correlated inversely with blood lactic acid concentration. In conclusion, the obtained results showed that medium-intensive type of exercise, such as trot, interval or continuous, slightly affected plasma leptin level but significantly affected plasma ghrelin concentration in young Standardbred trotters.

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Diurnal variation of ghrelin, leptin, and adiponectin in Standardbred mares

Cited by 58 publications

References 26 publications

Variations of plasma leptin in show horses during a work season

Variations of plasma leptin in show horses during a work season

Plasma ghrelin concentrations change with physiological state in a sciurid hibernator (Spermophilus lateralis)

The effect of interval versus continuous exercise on plasma leptin and ghrelin concentration in young trotters

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