Changes of Leptin and Ghrelin Levels in the Early Lactation Period After Birth in Sheep

Abstract

Lactation is a period, which involves important changes of energy metabolism in ruminants. Leptin and ghrelin are hormones that play a critical role in the regulation of energy homeostasis. In this study we investigated levels of leptin and ghrelin hormones, which have roles on changes of energy metabolism, during early lactation period in sheep. Leptin and ghrelin levels of 10 sheep after birth were measured at the 4th and 6th weeks of the early lactation period. Hormone measurements were analyzed with using specific commercial ELISA kits. Leptin and Ghrelin levels were significantly lower in the 4th week than in the 6th week (P<0.05). There was also a high level of significant correlation between leptin and ghrelin levels. These results have shown that leptin and ghrelin peptides play a role in metabolism in response to energy changes in the early lactation and are simultaneously decreasing or increasing. This may be related to increased energy needs, weight loss, mobilization of adipose tissue lipids, or other hormonal regulatory mechanisms involved in energy metabolism as well as birth and postpartum breastfeeding.

Keywords

• Early Lactation,Ghrelin,Leptin,Sheep

Koyunlarda Doğum Sonrası Erken Laktasyon Döneminde Leptin ve Ghrelin Seviyelerin Değişimleri

Öz

Laktasyon, ruminantlarda enerji metabolizmasında önemli değişimlerin olduğu bir dönemdir. Leptin ve ghrelin enerji homeostazisinin düzenlenmesinde kritik rol oynayan hormonlardır. Bu çalışmada koyunlarda erken laktasyon döneminde oluşan enerji metabolizması değişimlerinde görev alan leptin ve ghrelin hormon seviyeleri incelendi. Hormon ölçümleri spesifik ticari elisa kitleri kullanılarak belirlendi. Doğumdan sonra 10 koyunun erken laktasyon döneminin 4. ve 6. haftalarındaki plazma leptin ve ghrelin seviyeleri ölçüldü. Leptin ve Ghrelin düzeyleri 4. haftada 6. haftaya göre anlamlı olarak düşük bulunduğu gözlendi (P<0.05). Ayrıca 6. haftada bu seviyelerin arttığı gözlendi. Ayrıca leptin ve ghrelin seviyeleri arasında yüksek düzeyde anlamlı korelasyon tespit edildi. Bu sonuçlar leptin ve ghrelin peptitlerinin erken laktasyonda meydana gelen enerji değişimlerine cevaben metabolizmada birlikte rol oynadıkları ve eş zamanlı azalıp arttıklarını göstermiştir. Bu durum doğum ve doğum sonrası emzirme ile beraber, artan enerji ihtiyacı, kilo kayıpları ve adipoz dokudaki lipitlerin mobilizasyonu ya da enerji metabolizmasında görev alan başka hormonal düzenleme mekanizmaları ile ilgili olabilir.

Anahtar Kelimeler

• Erken Laktasyon,Ghrelin,Koyun,Leptin

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