Abstract
Background:
The gastrointestinal (GI) tract exhibits regional structural and endocrine specialization that is essential for digestive regulation. However, information on the gastric and intestinal endocrine organization of viverrid species remains limited.

Aim:
This study aimed to investigate the anatomy, histology, and endocrine cell distribution in the stomach and duodenum of the Asian palm civet (Paradoxurus hermaphroditus).

Methods:
Stomachs and duodenal segments were collected from three adult male Paradoxurus hermaphroditus obtained from the Special Region of Yogyakarta, Indonesia. Animals were euthanized with Ketamin-Xylazine in accordance with ethical guidelines. Gross anatomical observations were conducted, followed by histological examination using haematoxylin–eosin (HE) staining. Immunohistochemistry (IHC) was performed to identify enteroendocrine cells using antibodies against chromogranin A (CgA), gastrin, serotonin (5-HT), and somatostatin (SST). Endocrine cell distribution was evaluated qualitatively in the part of the stomach (cardiac-fundus-pyloric) and duodenal regions.

Results:
The stomach exhibited clear regional differentiation at the gross and histological levels. Chromogranin A–immunoreactive cells were detected throughout all examined regions. Serotonin-immunoreactive cells were widely distributed in the stomach and were most prominent in the duodenum. Somatostatin-immunoreactive cells were observed in the fundic–body, pyloric, and duodenal regions. Gastrin-immunoreactive cells were predominantly localized to the pyloric glands and represented the most abundant endocrine population in this region.

Conclusion:
The stomach and duodenum of Paradoxurus hermaphroditus show a regionally organized endocrine system closely associated with gross and histological specialization. The pylorus region showed strong gastrin and somatostatin immunoreactive cell distribution, resembling the typical endocrine regulatory pattern reported in other carnivoran mammals, while the duodenum demonstrated serotonin-dominant signalling associated with intestinal motility and secretion. The widespread distribution of chromogranin A-positive cells throughout the gastrointestinal tract further supports a conserved carnivoran-type gastrointestinal endocrine organization in this viverrid species despite its opportunistic omnivorous-frugivorous feeding behaviour.

Key words: Asian palm civet (Paradoxurus hermaphroditus); duodenum; enteroendocrine cells; immunohistochemistry; stomach