Histomorphological and Histochemical Study of Esophagus and Stomach in the Neonate Guinea Pigs (Cavia porcellus)

Abstract

This study aimed to investigate the histomorphological changes that occur in the esophagus and stomach during the postnatal periods of guinea pigs' lives. For this purpose, pregnant guinea pigs in good health condition were obtained from public markets and housed in the animal facility until delivery to obtain neonate guinea pigs. Ten pups were separated from their mothers on the second day of their lives and euthanized using an overdose of ketamine HCl (85-95 mg/kg BW). The topographic position of organs was observed in situ, and samples were collected in 10% neutral buffered formalin for routine histological procedures. The results showed that in neonate guinea pigs, the esophagus was a narrow muscular tube approximately 1.47±0.02 cm in length and 0.044±0.02 gm in weight, divided according to its position into three portions. The stomach was a transverse, transparent, whitish-pink sac-like structure of the digestive system with a weight of 1.13±0.05 gm, a length of 2.76±0.04 cm, and a capacity of 2.57±0.08 ml. The stomach lacks an outward demarcation-limiting ridge between its divisions and appears relatively lobulated. This age was characterized by longitudinal and translational folds along the entire inner surface. Histologically, both organs were composed of the same four basic layers. Due to some of its distinct anatomical and physiological characteristics, this animal species is valuable as a model in numerous scientific investigations. Therefore, this study sheds light on the histomorphological and histochemical properties of these organs, supporting further studies on vital digestive tract functions such as food processing and absorption.