Lungs of Bat (Eidolon helvum), RAT (Rattus norvegicus) and Pangolin (Manis tricuspis): A Comparative Histology

Abstract

Aims: The histology of the lungs of three mammalian species were examined to explore how their histological differences may determine their functional features, which may be compared by differences in their life styles. Study Design: The histological investigations of the lungs of occational flying specie, bat (Eidolon helvum); the slow or sluggish specie, pangolin (Manis tricuspis); and running or walking specie, wistar rat (Rattus norvegicus) were studied. Methodology: Two (2) bats, two (2) rats and one (1) pangolin were acclimatized (in the animal holding of the University of Ilorin) and used for this research work, the animals were sacrificed using cervical dislocation under chloroform anaesthesia, after which the lungs were extracted and fixed in a 10% formalin for 24 hours, and prepared for histological examinations.            Results: The alveolar duct in bat is slightly thinner in bat compared to that of rat, and thinnest in pangolin. Also, the macrophages found in rat are larger than that in bat. More epithelial type I cells are found in rat compared to bat and scanty in the pangolin, and more of epithelial type II cells are found in bat compared to rat and very most in pangolin. The macrophages found in rat are larger than that in bat. The macrophages that are larger in the ground running animals may suggest that, the earth closer animal requires more antibodies for self defence compared to flying animals. Conclusion: It can therefore be concluded that, the differences in the histological features may determine the respiratory functions of the animals involved.