Histological Changes in the Testicular Architecture and Spermatogenic Kinetics of Rats Following Subchronic Inhalation of Formaldehyde

International Journal of Anatomy and Physiology | Vol. 15, No. 11, November 2026 | pp. 190–198

DOI: 10.46882/2026/IJAP/001022

Research Article

Title: Histological Changes in the Testicular Architecture and Spermatogenic Kinetics of Rats Following Subchronic Inhalation of Formaldehyde

Names of Authors: S. B. V基礎¹, O. P. Popoola²*

Authors’ Affiliations:
¹ Department of Anatomy, Faculty of Medicine, University of Nis, Nis, Serbia.
² Department of Anatomy, College of Medicine, University of Ibadan, Ibadan, Nigeria.

Abstract:
Formaldehyde is an industrial pollutant and common fixative chemical linked to tissue damage via oxidative stress pathways. This study examined the subchronic toxicological effects of formaldehyde gas inhalation on the histomorphology of seminiferous tubules and spermatogenic cell lineages in Wistar rats. Twenty-four male rats were distributed into three groups (n = 8): Control (ambient air), Low-Exposure (5 mg/m³ formaldehyde), and High-Exposure (15 mg/m³ formaldehyde), exposed for 4 hours per day, 5 days a week, over a 10-week period. Testicular sections were processed and evaluated using Johnsen's scoring system alongside morphometric measurements of tubular diameter and epithelial height. Inhalation of high-dose formaldehyde caused notable disruptions to testicular architecture. The mean seminiferous tubular diameter decreased significantly (185 ± 12 μm vs. 245 ± 18 μm in controls; p < 0.01), accompanied by a reduction in germinal epithelial height (42 ± 3.4 μm vs. 68 ± 5.1 μm; p < 0.01). Johnsen’s score dropped from 9.4 ± 0.3 in controls to 5.8 ± 0.4 in the high-exposure group, indicating spermatogenic arrest at the primary spermatocyte level. Disorganization of Sertoli cells, vacuolation of the basal compartment, and a significant decrease in interstitial Leydig cell numbers were noted. These findings show that subchronic formaldehyde exposure induces structural testicular degeneration and impairs spermatogenic kinetics, presenting potential risks to male reproductive health.

Keywords: Formaldehyde, Testis, Seminiferous tubules, Spermatogenesis, Histomorphometry.

Manuscript Timeline: Received: August 14, 2026; Revised: October 02, 2026; Accepted: October 22, 2026; Published: November 12, 2026.

Citation: V基礎 SB, Popoola OP. Histological Changes in the Testicular Architecture and Spermatogenic Kinetics of Rats Following Subchronic Inhalation of Formaldehyde. International Journal of Anatomy and Physiology. 2026; 15(11): 190–198. doi:10.46882/2026/IJAP/001022

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