Dose Dependent Proliferation of Testicular Tissue Subsequent to Exogenous Neurokinin B Administration in Adult New Zealand White Rabbits

Background: Neurokinin B is a regulator of puberty and reproduction, however its chronic effects on gonads in adult male mammals remain elusive. Objectives: To investigate potentials of variable doses of Neurokinin B on histomorphology of testicular tissue and serum testosterone levels in adult rabbits. Material and Methods: This Laboratory based experimental study was conducted at Gomal Centre of Biochemistry and Biotechnology, Gomal University, Dera Ismail Khan, Pakistan from June-2019 to June-2020. Adult male New Zealand white rabbits (n=18) with an average weight of 1.52kg were randomly assigned to three groups. Study animals were administered subcutaneously with Neurokinin B in two variable doses: 1 µg and 1 çg. Control rabbits were injected with distilled water. After 12 days of continuous peptide treatment, animals (n=06) in each group were sacrificed. Testicular tissues were dissected and processed for light microscopy. Blood collection was performed directly from left ventricle, serum was separated and assayed for testosterone by enzyme linked immunosorbent assay.Results: Neurokinin B did not alter the body weight of experimental rabbits as compared to control. No significant change on testicular weight, testicular volume and gonadosomatic index was observed at any dose of Neurokinin B. Seminiferous tubular diameter (µm) increased non-significantly while seminiferous epithelial height (µm) increased significantly in high dose group as compared to control group. Serum testosterone concentration increased significantly (P?0.01) at both low (1çg) and high (1µg) doses of Neurokinin B as compared to control.Conclusion: Continuous administration of Neurokinin B effect positively on serum testosterone and testicular morphology.Keywords: Histomorphology, Neurokinin B, Tachykinins, Testes, Testosterone