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Öz

The corpus luteum (CL) forms after ovulation and plays an important role in the maintenance of pregnancy. Besides, it is a functional structure temporarily secreting progesterone and having endocrine activity. In cattle, the luteolysis generally occurs in two phases. These are classified as functional and structural luteolysis. Structural luteolysis is distinguished from the structural luteolysis with CL’s structural involution. During luteolysis, many vasoactive agents are stimulated such as nitric oxide, endothelin-I, angiotensin II, and oxytocin. In recent years, an increase has been found in the luteal blood flow at the beginning of the luteolysis, as determined by colour Doppler ultrasonography. The purpose of this review was to explain both various mechanisms about the vasoactive agents responsible in the luteolysis and their reciprocal interactions.

Anahtar Kelimeler

• Corpus luteum, Cow, Luteolysis, Vasoactive agent.

İneklerde Luteolizis Mekanizması ve Vazoaktif Ajanları

Öz

Korpus luteum (CL) ovulasyon sonrasında şekillenir ve gebeliğin devamlılığında rol oynar. Ayrıca geçici bir süre progesteron salgılayan endokrin etkinliği bulunan fonksiyonel bir yapıdır. Sığırlarda luteolizis temel olarak iki fazda meydana gelir. Bunlar fonksiyonel ve yapısal luteolizis olarak sınıflandırılır. Yapısal luteolizis, fonksiyonel luteolizisten CL’nin yapısal involüsyonu ile ayırt edilebilir. Luteolizis sırasında nitrik oksit, endotelin-I, angiotensin-II ve oksitosin gibi birçok vazoaktif ajan uyarılır. Son yıllarda renkli Doppler ultrasonografi kullanılması ile luteolizis başlangıcında luteal kan akımında artış olduğu tespit edilmiştir. Bu derlemenin amacı, Doppler ultrasonografi kullanılarak luteoliziste değişen mekanizmalar, vazoaktif ajanların bu süreçteki görevleri ve aralarındaki ilişkiler hakkında bilgi vermektir. 

Anahtar Kelimeler

• İnek, Korpus luteum, Luteolizis, Vazoaktif ajan.

Kaynakça

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