Daily Patterns and Adaptation of the Ghrelin, Growth Hormone and Insulin-Like Growth Factor-1 System Under Daytime Food Synchronisation in Rats
Daytime restricted feeding promotes the re‐alignment of the food entrained oscillator (FEO). Endocrine cues which secretion is regulated by the transition of fasting and feeding cycles converge in the FEO. The present study aimed to investigate the ghrelin, growth hormone (GH) and insulin‐like growt...
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Published in | Journal of neuroendocrinology Vol. 26; no. 5; pp. 282 - 295 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Blackwell Publishing Ltd
01.05.2014
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Daytime restricted feeding promotes the re‐alignment of the food entrained oscillator (FEO). Endocrine cues which secretion is regulated by the transition of fasting and feeding cycles converge in the FEO. The present study aimed to investigate the ghrelin, growth hormone (GH) and insulin‐like growth factor (IGF)‐1 system because their release depends on rhythmic and nutritional factors, and the output from the system influences feeding and biochemical status. In a daily sampling approach, rats that were fed ad lib. were compared with rats on a reversed (daytime) and restricted feeding schedule by 3 weeks (dRF; food access for 2 h), also assessing the effect of acute fasting and refeeding. We undertook measurements of clock protein BMAL1 and performed somatometry of peripheral organs and determined the concentration of total, acylated and unacylated ghrelin, GH and IGF‐1 in both serum and in its main synthesising organs. During dRF, BMAL1 expression was synchronised to mealtime in hypophysis and liver; rats exhibited acute hyperphagia, stomach distension with a slow emptying, a phase shift in liver mass towards the dark period and decrease in mass perigonadal white adipose tissue. Total ghrelin secretion during the 24‐h period increased in the dRF group as a result of elevation of the unacylated form. By contrast, GH and IGF‐1 serum concentration fell, with a modification of GH daily pattern after mealtime. In the dRF group, ghrelin content in the stomach and pituitary GH content decreased, whereas hepatic IGF‐1 remained equal. The daily patterns and synthesis of these hormones had a rheostatic adaptation. The endocrine adaptive response elicited suggests that it may be associated with the regulation of metabolic, behavioural and physiological processes during the paradigm of daytime restricted feeding and associated FEO activity. |
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Bibliography: | CONACYT - No. 49047; No. 178335 FONCICYT - No. 91984 ark:/67375/WNG-THNV5B5X-1 istex:74A19C8053DD5F6267BA6634686222DB28C8E110 PAPIIT - No. IN201209; No. IN208812; No. IN210209 ArticleID:JNE12145 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0953-8194 1365-2826 |
DOI: | 10.1111/jne.12145 |