Subcutaneous Implantation of Exogenous Melatonin Induces a Polarization Effect on the Weight of Scent Glands in Muskrat

The muskrat ( Ondatra zibethicus ) is a small, semi‐aquatic rodent notable for its scent glands, which secrete a substance containing muscone. Melatonin (MLT) has been demonstrated to reduce oxidative stress, inflammation, and apoptosis. However, its role in the development of muskrat scent glands remains unclear. This study investigated the effects of 20 mg MLT on the scent glands of muskrat. The results showed that administration of 20 mg MLT resulted in polarized changes in gland weight: some individuals (M‐A group) exhibited a decrease in gland weight, while others (group M‐B) showed an increase. We observed that MLT treatment significantly upregulated the mRNA levels of PI3K, Bcl‐2, and JNK in the scent glands of the M‐A group. However, MLT did not demonstrate significant activation of the downstream signaling pathways of PI3K (Akt, p21, CDK1, and Cyclin B1), mitochondrial apoptosis markers (Bax, Caspase9, CytC), or the FGF 20‐H‐Ras‐MAPK 1 signaling axis. Our findings provide preliminary insights into the impact of MLT on the development and secretion of scent in muskrat, offering important reference points for future related research.