Morphological, histological, and histochemical study of the adult golden hamster (Mesocricetus auratus) spleen

BACKGROUND: The golden hamster is a choice model for investigating many visceral and splenic infections and neoplastic and retrospective lesions. AIM: To study hamsters' spleen's morphological, histological, and histochemical structure. METHODS: Samples were collected from eight healthy adult golden hamsters and then fixed with 10% buffered formalin. Later, samples were processed, sectioned, and stained with Hematoxylin and Eosin as well as Masson’s Trichrome stain. Other slides were further stained with Periodic Acid Schiff and Alcian blue 2.5 stain (PAS) for histochemical evolution; the gross measurement was performed for the splenic length, width, and thickness, while the histological measures included the splenic capsular and trabecula thickness, diameter of white pulp follicles, splenic sinusoids and central arteries and proportion of white and red pulps. RESULTS: The macroscopic findings revealed that the spleen was red-brown lanciform on the left side of the dorsolateral abdominal wall. The morphological measurements for splenic length, width, and thickness were 26.6 ± 7.67, 4.17 ± 1.65, and 1.70 ± 0.01 mm, respectively. The histological observations showed that the splenic capsule was composed of two layers (serosal and subserosal). The inner layer sends trabeculae dividing the splenic parenchyma irregularly, and the splenic parenchyma comprises the white and red pulp. The white pulp follicles included the mantle, marginal zones, and the PALS (periarterial lymphatic sheath), while the red pulp constituted splenic cords and sinuses. The histomorphological findings showed that white pulp follicles and the central artery mean diameter were 252.62 ± 8.07 µm and 54.45 ± 0.36 µm respectively, the proportion of white to a red pulp was 0.49 ± 0.01, the splenic capsule, trabecula and the wall of splenic arteries showed an intense positive activity to PAS stain and negative or weak in other splenic structures. CONCLUSION: The similarities and differences in the spleen between the laboratory animals and hamsters were apparent in this article, so understanding the morphological and histological structure of the spleen presents significant assistance with species identification to select the appropriate experimental animal model in future medical research