Gebe kısraklarda ve yeni doğan taylarda trioid hormon konsantrasyonları

Bu çalışmada safkan, sağlıklı 24 kısrakta ve onların taylarında (Arap, 11=8/8; İngiliz, n=8/8 ve Hannover, n=8/8) bazı tiroid bezi parametrelerinin normal doğum ve neonatal adaptasyon dönemindeki değişimleri incelendi. Doğumdan hemen sonra, yeni doğan taylarda tiroksin konsantrasyonu annelerinden oldukça yüksekti. Yeni doğan taylardaki oldukça yüksek olan bu ortalama T4 seviyesi hayatın ilk 12 saati içinde çok hızlı düşüş gösterdi. Tiroksin konsantrasyonunun ilk 12 saat içindeki düşüşünden sonra tiroidal sistemde belirgin şekilde stabilizasyon görüldü. Onuncu günün sonunda yeni doğan taylarda tiroksin konsantrasyonu annelerine kıyasla yine de yüksekti. ' Triiyodotironin konsantrasyonu doğumdan kısa bir süre sonra artmaya başladı, en yüksek triiyodotironin konsantrasyonlarına 3. ve 15. saatler arasında ulaştı. Tüm çalışma boyunca yeni doğan taylarda triiyodotironin seviyesi annelerinden daha yüksekti. . Yaşamın ilk saatlerinde tiroidal parametreler önemli değişiklikler gösterdi ve tiroidal sistemin post natal döneme uyumunun üç ayrı faza ayrılmasına olanak sağladı: 1.Faz: Doğumdan sonra 3. saate kadar olan dönemde tiroidal sistemin kuvvetli bir şekilde uyarılması. 2.Faz: 3. güne kadar olan dönemde tiroidal aktivitelerin belirgin şekilde azalması. 3.Faz: Yeni doğan taylarda tiroidal sistemin uterus dışı hayata uyum sağlaması.

The thyroid hormon concentrations of the pregnant mares and newborn foals

The biochemical analysis of 24 healthy thoroughbred mares and their foals (Arab, n=8/8; English, n=8/8; and Hannoverian, n=8/8) were investigated for some thyroidal parameters of normal partus and postnatal adaptation. After the first hours of life the thyroxine concentration of newborn foals was higher compared to that of their mothers and the thyroxine concentrations decreased rapidly during first 12 hours of life. Tweve hours of post partum after declining of thyroxine, the thyroidal system seemed to be stabilized. After ten days, in comparison with that of their mothers the thyroxine level of the foals was still higher. The increase of triiodothyronine begins shortly after birth and very high concentrations were found between the 3rd and 15lh hour. During observation time, triiodothyronine of the newborn foals remained higher than that of the mares. In the first hours of life thyroidal parameters of newborn foals were changed very extremely. According to the measured and calculated thyroidal rates postnatal adaptation can be divided to in three phases: Phase 1: Strongly thyroidal stimulation in the first 3 hours of life. Phase 2: Decreased thyroidal activity until the 3rd day of life. Phase 3: The thyroidal system of newborn foals adapted to the extrauterine life.

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