Structural characteristics and gastric endocrine cell distribution in the stomach of the Asian palm civet (Paradoxurus hermaphroditus)

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 aims to investigate the anatomy, histology, and endocrine cell distribution in the stomach and duodenum of the Asian palm civet (Paradoxurus hermaphroditus). Methods: Stomach and duodenal segments were collected from three adult male P. hermaphroditus obtained from the special region of Yogyakarta, Indonesia. The animals were euthanized with ketamin–xylazine in accordance with ethical guidelines. Gross anatomical observations were conducted, followed by histological examination using haematoxylin–eosin staining. Immunohistochemistry was performed to identify enteroendocrine cells using antibodies against chromogranin A (CgA), gastrin, serotonin, and somatostatin (SST). Endocrine cell distribution was evaluated qualitatively in the part of the stomach (cardiac, fundic, and pyloric) and duodenal regions. Results: The stomach exhibited clear regional differentiation at both the gross and histological levels. CgA– immunoreactive cells were detected throughout all examined regions. Serotonin-immunoreactive cells were widely distributed in the stomach and were most prominent in the duodenum. SST-immunoreactive cells were observed in the fundic–body, pyloric region, and duodenal regions. Gastrin-immunoreactive cells were predominantly localized in the pyloric glands and represented the most abundant endocrine population in this region. Conclusion: The stomach and duodenum of P. hermaphroditus show a regionally organized endocrine system closely associated with gross and histological specialization. The pylorus region showed strong gastrin-and SST-immunoreactive cell distribution, resembling the typical endocrine regulatory pattern reported in other carnivorous mammals, while the duodenum demonstrated serotonin-dominant signaling associated with intestinal motility and secretion. The widespread distribution of CgA-positive cells throughout the GI tract further supports a conserved carnivoran-type GI endocrine organization in this viverrid species, despite its opportunistic omnivorous–frugivorous feeding behavior.