Swesme Enyioma-Alozie
Department of Anatomy, Faculty of Basic Medical Sciences, Baze University, Abuja, Nigeria
*Corresponding author’s Email: swesme.alozie@bazeuniversity.edu.ng, doi.org/10.55639/607.020100143
ABSTRACT
Fentanyl, a synthetic opioid, is used pharmaceutically for pain management, even as concerns has consistently been raised about its growing misuse, and the consequences on delicate body systems such as the male reproductive system. Even though opioids are known to affect the endocrine system, the evidence of fentanyl’s direct influence on sperm quality and testicular histology have been under-explored. This study aimed to evaluate the effect of fentanyl administration on sperm parameters, serum testosterone levels, and testicular histology in adult male Wistar rats. Twenty-five (25) adult male Wistar rats were randomly divided into five groups (n=5). The control group received 5 mL/kg distilled water, while groups 2–5 received intramuscular fentanyl at doses of 1 µg/kg, 1.5 µg/kg, 2 µg/kg, and 2.5 µg/kg, respectively, for 21 d. After treatment, body weight, serum testosterone concentration, and sperm indices were assessed, and testicular tissues were histologically examined using hematoxylin and eosin staining. All groups gained weight over the course of the study, but treated groups showed a non-significantly smaller weight gain than control, with the smallest weight gain recorded in group 5 (57.32±8.03 g) compared to the control (86.00±24.02 g) (p>0.05). Testosterone levels decreased slightly in fentanyl groups (0.98±0.15 ng/mL to 1.30±0.10 ng/mL) relative to control (2.93±0.92 ng/mL). Sperm count increased in treated rats, peaking in group 4 (51.13±17.54) compared to control (26.75±22.45), though not significantly. Testicular histology revealed intact seminiferous tubules, normal spermatogenic architecture, and preserved Leydig cells across all groups. Fentanyl administration for 21 d induced mild, non-significant alterations in body weight, testosterone levels, and sperm parameters, without histological evidence of testicular damage. The results of this research show that intramuscular fentanyl at the doses administered in this study could influence latent reproductive effects. Biomarker based approaches could be a better option in reproductive toxicology when carrying out preclinical drug safety analysis and reproductive risk evaluation.
KEYWORDS
Fentanyl,
Testicular
histology,
Sperm
parameters,
Testosterone,
Male fertility.