Daily patterns of plasma leptin in sheep

effects of photoperiod and food intake

M Marie, P A Findlay, Louise Thomas, Clare Lesley Adam

Research output: Contribution to journalArticle

113 Citations (Scopus)

Abstract

Circulating concentrations of leptin in sheep correlate with body fatness and are affected by level of food intake and photoperiod. The present objective was to elucidate the short-term dynamics of leptin secretion. Frequent blood samples were taken over 48 h from 12 Soay rams after 16 weeks in short-day photoperiod (SD, 16 h darkness:8 h light) with freely available food, and then after 16 weeks in long days (16 h light:8 h darkness) with food freely available (LD) or restricted to 90% maintenance (LDR) (n=6/ group). During the second 24 h of sampling, half were food deprived (,n=6, SD and LD) and half had their meal times shifted (n=6, SD and LDR). A homologous RIA was developed, using antibodies raised in chicken against recombinant ovine leptin, to measure plasma concentrations. Simultaneous 24 h profiles of plasma insulin, glucose and non-esterified fatty acids (NEFA) were measured. Plasma leptin was higher in LD than SD, and in LD than LDR, associated with higher food intake, liveweight and body condition score (adiposity), but tended to be lower in LDR than SD, associated with lower food intake, Liveweight and body condition score. There was no evidence for a circadian rhythm of plasma leptin, but clear evidence for post-prandial peaks of low amplitude (15-36%) 2-8 h after meals given at normal and shifted times. Complete food deprivation caused a dramatic fail in plasma leptin to basal levels within 24 h. There was a positive association of plasma leptin with plasma insulin, and negative association with NEFA, both between meals and during fasting. Thus, plasma leptin concentrations in sheep are sensitive to short-term changes in energy balance, as well as to long-term photoperiod-driven changes in food intake and adiposity.

Original languageEnglish
Pages (from-to)277-286
Number of pages10
JournalJournal of Endocrinology
Volume170
Issue number1
DOIs
Publication statusPublished - Jul 2001

Keywords

  • CIRCULATING LEPTIN
  • GENE-EXPRESSION
  • OBESE
  • INSULIN
  • WEIGHT
  • NUTRITION
  • GROWTH
  • HORMONE
  • RHYTHM
  • LEVEL

Cite this

Daily patterns of plasma leptin in sheep : effects of photoperiod and food intake . / Marie, M ; Findlay, P A ; Thomas, Louise; Adam, Clare Lesley.

In: Journal of Endocrinology, Vol. 170, No. 1, 07.2001, p. 277-286.

Research output: Contribution to journalArticle

Marie, M ; Findlay, P A ; Thomas, Louise ; Adam, Clare Lesley. / Daily patterns of plasma leptin in sheep : effects of photoperiod and food intake . In: Journal of Endocrinology. 2001 ; Vol. 170, No. 1. pp. 277-286.
@article{2f2f8d449c9e4654972cc4347e19f900,
title = "Daily patterns of plasma leptin in sheep: effects of photoperiod and food intake",
abstract = "Circulating concentrations of leptin in sheep correlate with body fatness and are affected by level of food intake and photoperiod. The present objective was to elucidate the short-term dynamics of leptin secretion. Frequent blood samples were taken over 48 h from 12 Soay rams after 16 weeks in short-day photoperiod (SD, 16 h darkness:8 h light) with freely available food, and then after 16 weeks in long days (16 h light:8 h darkness) with food freely available (LD) or restricted to 90{\%} maintenance (LDR) (n=6/ group). During the second 24 h of sampling, half were food deprived (,n=6, SD and LD) and half had their meal times shifted (n=6, SD and LDR). A homologous RIA was developed, using antibodies raised in chicken against recombinant ovine leptin, to measure plasma concentrations. Simultaneous 24 h profiles of plasma insulin, glucose and non-esterified fatty acids (NEFA) were measured. Plasma leptin was higher in LD than SD, and in LD than LDR, associated with higher food intake, liveweight and body condition score (adiposity), but tended to be lower in LDR than SD, associated with lower food intake, Liveweight and body condition score. There was no evidence for a circadian rhythm of plasma leptin, but clear evidence for post-prandial peaks of low amplitude (15-36{\%}) 2-8 h after meals given at normal and shifted times. Complete food deprivation caused a dramatic fail in plasma leptin to basal levels within 24 h. There was a positive association of plasma leptin with plasma insulin, and negative association with NEFA, both between meals and during fasting. Thus, plasma leptin concentrations in sheep are sensitive to short-term changes in energy balance, as well as to long-term photoperiod-driven changes in food intake and adiposity.",
keywords = "CIRCULATING LEPTIN, GENE-EXPRESSION, OBESE, INSULIN, WEIGHT, NUTRITION, GROWTH, HORMONE, RHYTHM, LEVEL",
author = "M Marie and Findlay, {P A} and Louise Thomas and Adam, {Clare Lesley}",
year = "2001",
month = "7",
doi = "10.1677/joe.0.1700277",
language = "English",
volume = "170",
pages = "277--286",
journal = "Journal of Endocrinology",
issn = "0022-0795",
publisher = "Society for Endocrinology",
number = "1",

}

TY - JOUR

T1 - Daily patterns of plasma leptin in sheep

T2 - effects of photoperiod and food intake

AU - Marie, M

AU - Findlay, P A

AU - Thomas, Louise

AU - Adam, Clare Lesley

PY - 2001/7

Y1 - 2001/7

N2 - Circulating concentrations of leptin in sheep correlate with body fatness and are affected by level of food intake and photoperiod. The present objective was to elucidate the short-term dynamics of leptin secretion. Frequent blood samples were taken over 48 h from 12 Soay rams after 16 weeks in short-day photoperiod (SD, 16 h darkness:8 h light) with freely available food, and then after 16 weeks in long days (16 h light:8 h darkness) with food freely available (LD) or restricted to 90% maintenance (LDR) (n=6/ group). During the second 24 h of sampling, half were food deprived (,n=6, SD and LD) and half had their meal times shifted (n=6, SD and LDR). A homologous RIA was developed, using antibodies raised in chicken against recombinant ovine leptin, to measure plasma concentrations. Simultaneous 24 h profiles of plasma insulin, glucose and non-esterified fatty acids (NEFA) were measured. Plasma leptin was higher in LD than SD, and in LD than LDR, associated with higher food intake, liveweight and body condition score (adiposity), but tended to be lower in LDR than SD, associated with lower food intake, Liveweight and body condition score. There was no evidence for a circadian rhythm of plasma leptin, but clear evidence for post-prandial peaks of low amplitude (15-36%) 2-8 h after meals given at normal and shifted times. Complete food deprivation caused a dramatic fail in plasma leptin to basal levels within 24 h. There was a positive association of plasma leptin with plasma insulin, and negative association with NEFA, both between meals and during fasting. Thus, plasma leptin concentrations in sheep are sensitive to short-term changes in energy balance, as well as to long-term photoperiod-driven changes in food intake and adiposity.

AB - Circulating concentrations of leptin in sheep correlate with body fatness and are affected by level of food intake and photoperiod. The present objective was to elucidate the short-term dynamics of leptin secretion. Frequent blood samples were taken over 48 h from 12 Soay rams after 16 weeks in short-day photoperiod (SD, 16 h darkness:8 h light) with freely available food, and then after 16 weeks in long days (16 h light:8 h darkness) with food freely available (LD) or restricted to 90% maintenance (LDR) (n=6/ group). During the second 24 h of sampling, half were food deprived (,n=6, SD and LD) and half had their meal times shifted (n=6, SD and LDR). A homologous RIA was developed, using antibodies raised in chicken against recombinant ovine leptin, to measure plasma concentrations. Simultaneous 24 h profiles of plasma insulin, glucose and non-esterified fatty acids (NEFA) were measured. Plasma leptin was higher in LD than SD, and in LD than LDR, associated with higher food intake, liveweight and body condition score (adiposity), but tended to be lower in LDR than SD, associated with lower food intake, Liveweight and body condition score. There was no evidence for a circadian rhythm of plasma leptin, but clear evidence for post-prandial peaks of low amplitude (15-36%) 2-8 h after meals given at normal and shifted times. Complete food deprivation caused a dramatic fail in plasma leptin to basal levels within 24 h. There was a positive association of plasma leptin with plasma insulin, and negative association with NEFA, both between meals and during fasting. Thus, plasma leptin concentrations in sheep are sensitive to short-term changes in energy balance, as well as to long-term photoperiod-driven changes in food intake and adiposity.

KW - CIRCULATING LEPTIN

KW - GENE-EXPRESSION

KW - OBESE

KW - INSULIN

KW - WEIGHT

KW - NUTRITION

KW - GROWTH

KW - HORMONE

KW - RHYTHM

KW - LEVEL

U2 - 10.1677/joe.0.1700277

DO - 10.1677/joe.0.1700277

M3 - Article

VL - 170

SP - 277

EP - 286

JO - Journal of Endocrinology

JF - Journal of Endocrinology

SN - 0022-0795

IS - 1

ER -