Central (CSF) and Circulating (serum) Sex Hormones May İnfluence Ocular Surface Temperature in Bitches

Abstract

This study investigated associations between serum and cerebrospinal fluid (CSF) estradiol (E2) and progesterone (P4) levels and body temperature regulation in thirty clinically healthy bitches. Right and left corneal temperatures (RCT, LCT), perianal and perivulvar temperatures were measured by infrared thermography, while rectal (RT) and intravaginal temperatures were recorded digitally. Hormone concentrations were determined by enzyme-linked immunosorbent assay (ELISA), and correlations were analyzed using Pearson’s test. CSF E2 and P4 levels were significantly higher than serum concentrations (p = 0.007 and p = 0.0001). CSF E2 showed a moderate positive correlation with LCT (r = 0.423, p = 0.041), and CSF P4 was similarly correlated with LCT (r = 0.347, p = 0.035). In contrast, serum P4 was negatively correlated with LCT (r = −0.341, p = 0.039) and RT (r = −0.423, p = 0.009). Perianal temperature demonstrated the strongest association with corneal temperatures, particularly RCT (r = 0.621, p < 0.001). CSF E2 and P4 were strongly correlated (r = 0.640, p < 0.001). These findings suggest that central sex hormones may play a more prominent role than peripheral hormones in ocular surface and regional thermoregulation in bitches Keywords: Dog, estradiol, progesterone, cerebrospinal fluid, corneal surface temperature.

Keywords

• Dog
• estradiol
• progesterone
• cerebrospinal fluid
• corneal surface temperature

Ethical Statement

This research study was conducted in accordance with research and publication ethics. This study was approved by the Kastamonu University Local Ethics Committee for Animal Experiments (2026/12).

Dişi Köpeklerde Merkezi (BOS) ve Dolaşımdaki (Serum) Cinsiyet Hormonları Oküler Yüzey Sıcaklığını Etkileyebilir

Abstract

Bu çalışma, klinik olarak sağlıklı otuz dişi köpekte serum ve beyin omurilik sıvısı (BOS) östradiol (E2) ve progesteron (P4) düzeyleri ile vücut sıcaklığı regülasyonu arasındaki ilişkileri araştırmıştır. Sağ ve sol kornea sıcaklıkları (RCT, LCT), perianal ve perivulvar sıcaklıklar kızılötesi termografi ile; rektal ve intravajinal sıcaklıklar ise dijital olarak ölçülmüştür. Hormon konsantrasyonları ELISA yöntemiyle belirlenmiş, korelasyonlar Pearson analizi ile değerlendirilmiştir. BOS E2 ve P4 düzeyleri serumdan anlamlı derecede yüksek bulunmuştur (p = 0,007 ve p = 0,0001). BOS E2, LCT ile orta düzeyde pozitif korelasyon göstermiştir (r = 0,423, p = 0,041); BOS P4 de LCT ile benzer şekilde pozitif korelasyon göstermiştir (r = 0,347, p = 0,035). Buna karşılık serum P4, LCT (r = −0,341, p = 0,039) ve rektal sıcaklık (r = −0,423, p = 0,009) ile negatif korelasyon göstermiştir. Perianal sıcaklık, özellikle RCT ile (r = 0,621, p < 0,001) en güçlü ilişkiyi göstermiştir. BOS E2 ve P4 arasında güçlü pozitif korelasyon saptanmıştır (r = 0,640, p < 0,001). Bu bulgular, merkezi cinsiyet hormonlarının oküler yüzey ve bölgesel termoregülasyonda periferik hormonlara kıyasla daha belirgin rol oynayabileceğini düşündürmektedir.

Keywords

• Köpek
• östradiol
• progesterone
• beyin-omurilik sıvısı
• kornea yüzey sıcaklığı

Ethical Statement

Bu araştırma, araştırma ve yayın etiği kurallarına uygun olarak yürütülmüştür. Gerekli Etik Kurul İzni Kastamonu Üniversitesi Hayvan Deneyleri Yerel Etik Kurulu tarafından verilmiştir (2026/12).

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