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

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.