Abstract
Background:
The adrenal gland is a key endocrine organ involved in hormonal regulation, stress response, and reproductive function across mammalian species. In wild carnivores such as the Javan mongoose (Urva javanica), information regarding adrenal gland morphology and androgen receptor (AR) distribution remains scarce.

Aim:
This research focuses on examining the anatomical and histological characteristics of the adrenal glands in U. javanica and investigating the distribution of androgen receptor-immunoreactive (AR-IR) cells within them.

Methods:
Six adrenal glands obtained from male and female Javan mongooses were examined using gross anatomical observation, routine histology, and immunohistochemical staining. Tissue samples were analysed to distinguish the cortical zones—zona glomerulosa (ZG), zona fasciculata (ZF), and zona reticularis (ZR)—as well as the medulla, and to determine the distribution of AR-IR cells.

Results:
Macroscopically, the adrenal glands were located near the cranial poles of the kidneys and exhibited a consistent morphology with subtle asymmetry between the right and left glands. Histologically, the six pairs of adrenal glands showed a well-defined cortical and medullary organization comparable to that of other mammals. Immunohistochemical examination showed that AR-IR cells were mainly concentrated in the ZF and ZR of the adrenal cortex, while no immunoreactivity was detected in the ZG or medulla. This distribution pattern indicates a distinct species-specific localization of androgen receptors in the adrenal glands of the Javan mongoose.

Conclusion:
These findings demonstrate a distinct, species-specific pattern of androgen receptor distribution in the adrenal glands of the Javan mongoose. The restricted localization of AR-IR cells to specific cortical zones suggests a targeted role of androgen signalling in adrenal function and highlights interspecies variation in endocrine regulation among wild mammals. Furthermore, this study provides baseline anatomical and immunohistochemical data for a relatively understudied wild species, contributing to a better understanding of comparative adrenal endocrinology in wildlife.

Key words: Adrenal cortex; Adrenal gland; Androgen receptor; Immunohistochemistry; Javan mongoose.