Abstract
Background:
The Javan mongoose (Urva javanica) is an endemic wild animal in Southeast Asia, including Indonesia, and is currently classified as an unprotected species. However, intensive hunting may lead to a population decline in its natural habitat, potentially altering its conservation status and posing a threat soon. Despite this concern, the anatomical data of the species remain limited. The digestive system of the Javan mongoose, an opportunistic carnivore, has not been previously documented. While a comprehensive examination of the entire digestive tract would offer broader insights, this study prioritizes the pancreas due to its central endocrine role in nutrient metabolism and adaptive feeding. This study provides the first baseline data on endocrine cell localization in Javan mongooses, laying the groundwork for future research on their digestive physiology.

Aim:
This study aimed to investigate the pancreatic structure of the Javan mongoose, with a specific focus on the distribution of pancreatic endocrine cells, including β, α, δ, and PP cells.

Methods:
Six Javan mongooses were obtained from a local hunter in Central Java, Indonesia. The anatomical and histological characteristics of the pancreas were examined, along with the expression of immunoreactive (IR) endocrine cells. Routine histological staining and immunohistochemistry (IHC) were performed. The data were analysed descriptively, semi-quantitatively, and quantitatively.

Results:
The pancreas of the Javan mongoose is located adjacent to the dorsal duodenum and the liver’s caudal segment. The exocrine component comprises acini and a ductal system, with ducts lined by low-to-medium cuboidal epithelium. Within the islets of Langerhans, β cells are predominantly concentrated in the central zone, while α cells are primarily located in the periphery. In contrast, δ and PP cells were uniformly distributed across the central, intermediate, and peripheral zones. Endocrine cells were also observed in the pancreatic ducts, highlighting a distinctive distribution pattern in the pancreas of Javan mongoose.

Conclusion:
The results reveal structural similarities to other mammalian species and highlight distinctive patterns in endocrine cell distribution, most notably, the presence of endocrine cells within the pancreatic ducts.

Key words: Anatomy; Immunohistochemistry; Pancreas; Javan mongoose (Urva javanica); Endocrine cell types.