The tissue distribution of nucleobindin-2/nesfatin-1 in the reproductive organs of bitches with regard to the animal's age and body weight.

Introduction: Neuropeptide nesfatin-1, a nucleobindin-2 derivative, plays a role in regulating food intake, energy metabolism and body weight. It also interacts with the hypothalamic-pituitary-gonadal axis and has functions in the reproductive system. However, its impact on the canine reproductive tract has not been well documented. This study aimed to investigate the potential role of nesfatin-1 in canine ovarian activity and uterine function. Material and Methods: Tissue and peripheral blood samples were collected from 60 bitches of various ages and body condition scores (BCS). Analyses included real-time PCR, immunofluorescence examinations and ELISA tests. Results: Higher level of nucleobindin-2 mRNA were found in the ovarian tissue of both younger and elderly overweight dogs (BCS > 5/9). The elevated expression of nesfatin-1 was observed in the uterine tissues of overweight dogs (BCS > 5/9) compared to its expression in animals in optimal body condition (BCS = 4/9). This finding was consistent with higher nesfatin-1 levels in the peripheral blood of overweight dogs. Conclusion: The distribution and expression of nesfatin-1 in canine reproductive organs vary depending on the animal's age and body weight. The role of nesfatin-1 in the reproductive system is influenced by the animal's body condition and the extent of surplus adipose tissue, which may have significant implications for reproductive functions.