Differential Impact of Subcutaneous Neurokinin B Administration on Epididymal Proliferation in Adult New Zealand White Rabbits: A Dose-Dependent Study

Objective: To investigate the potential of variable doses of Neurokinin B on histomorphology of epididymis in adult rabbits. Study Design: Laboratory-based experimental study. Place and Duration of Study: Gomal Centre of Biochemistry and Biotechnology, Gomal University, Dera Ismail Khan, Pakistan, from Jun 2019 to Jun 2020. Methodology: Adult male New Zealand White rabbits with an average weight of 1.5–2 Kg were randomly assigned to three groups. Study animals were administered subcutaneously with Neurokinin B in two variable doses: 1 µg and one ηg. Control rabbits were injected with distilled water in parallel. After 12 days of continuous peptide treatment, animals (n=06) in each group were sacrificed. Epididymis were dissected and processed for light microscopy and sperm count. Results: Mean epididymis weight (mg) increased significantly (p<0.001) with the treatment of Neurokinin B 1 ηg and Neurokinin B 1 µg as compared to control. With the increase in doses of Neurokinin B (1 ηg, 1 μg), the lumen of caput, corpus and cauda of the epididymis got significantly (p<0.001) dilated dose-dependently in Neurokinin B treated animals. Sperm count increased significantly (p<0.001) in the Neurokinin B-treated rabbits compared to the control. Light microscopy revealed increased luminal diameter compared to control in all Neurokinin B treated groups as compared to control. Conclusion: Continuous administration of Neurokinin B could benefit the epididymis, as shown by increased luminal diameter and sperm count.