Microscopic and computational analysis of the stomach, duodenum, and liver of rats with induced hyperprolactinemia treated with exogenous melatonin

João Vitor da Silva; Ryan Cristian da Silva; Renan Gabriel da Silva Ferreira; Alison José da Silva; Isaque Bertoldo Santos da Silva; Aline Maria Rodrigues Dos Santos; Bruno José do Nascimento; Elba Verônica Matoso Maciel de Carvalho; Francisco Carlos Amanajás de Aguiar Júnior; Ewerton Fylipe de Araújo Silva; Priscilla Virgínio de Albuquerque; Apolônio Gomes Ribeiro; Bruno Mendes Tenorio; Lucas Rannier Ribeiro Antonino Carvalho; Fernanda das Chagas Angelo Mendes Tenorio

doi:10.3389/fvets.2026.1709295

Microscopic and computational analysis of the stomach, duodenum, and liver of rats with induced hyperprolactinemia treated with exogenous melatonin

Front Vet Sci. 2026 May 14:13:1709295. doi: 10.3389/fvets.2026.1709295. eCollection 2026.

Authors

João Vitor da Silva¹, Ryan Cristian da Silva¹, Renan Gabriel da Silva Ferreira¹, Alison José da Silva¹, Isaque Bertoldo Santos da Silva¹, Aline Maria Rodrigues Dos Santos¹, Bruno José do Nascimento², Elba Verônica Matoso Maciel de Carvalho³, Francisco Carlos Amanajás de Aguiar Júnior⁴, Ewerton Fylipe de Araújo Silva⁵, Priscilla Virgínio de Albuquerque², Apolônio Gomes Ribeiro⁶, Bruno Mendes Tenorio¹, Lucas Rannier Ribeiro Antonino Carvalho⁷, Fernanda das Chagas Angelo Mendes Tenorio¹

Affiliations

¹ Department of Histology and Embryology, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
² Department of Animal Morphology and Physiology, Federal University Rural of Pernambuco, Recife, Pernambuco, Brazil.
³ Department of Biochemistry, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
⁴ Department of Histology, Federal University of Pernambuco, Vitória de Santo Antão, Pernambuco, Brazil.
⁵ Department of Anatomy, Federal University of Pernambuco, Vitória de Santo Antão, Pernambuco, Brazil.
⁶ Animal Science Department, Universidade Federal da Paraíba, Areia, Paraíba, Brazil.
⁷ Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.

Abstract

Introduction: This study evaluated the effects of exogenous melatonin (MEL) on morphological and computational alterations in the stomach, duodenum, and liver of hyperprolactinemic rats.

Methods: Twenty-four animals were divided into three groups: Control (n = 8), Hyper (n = 8), and Hyper+MEL (n = 8). Hyperprolactinemia was induced with domperidone (4 mg/kg/day, subcutaneously [s.c.]), and MEL was administered at 200 μg/100 g (s.c.).

Results: The Hyper group showed a higher body weight compared to the Control group, while both hyperprolactinemic groups exhibited gastric lumen dilation. PCNA immunolabeling increased in the liver and, to a lesser extent, in the stomach, while decreasing in the duodenum in the Hyper and Hyper+MEL groups. In the duodenum, both hyperprolactinemic groups exhibited increased villus and microvillus height, whereas a reduced Periodic Acid-Schiff (PAS)-stained area was detected only in the Hyper group. In the liver, microsteatosis, fewer Kupffer cells (KCs), and a higher number of binucleated hepatocytes were identified in hyperprolactinemic animals. Fractal analysis of goblet cells revealed no differences among groups. Serum MEL levels were elevated in the hyperprolactinemic groups, with the highest concentrations observed in the Hyper+MEL group.

Discussion: In summary, hyperprolactinemia induced structural alterations in the stomach, duodenum, and liver, whereas MEL administration exerted limited effects, mainly influencing body weight and duodenal histochemical parameters, without consistent protective effects on the other evaluated outcomes.

Keywords: digestive system; fractal; histopathology; hyperprolactinemia; melatonin.