Histological study of experimental hyperprolactinemia on the prostate lateral lobe of adult albino rats

Abstract

Introduction Prolactin, besides androgens, plays an important role in the regulation of prostatic function. Aim of the study This study aimed to demonstrate the influence of experimental hyperprolactinemia on the structure of the prostate lateral lobe in adult albino rats. Materials and methods Twenty healthy adult albino rats were equally divided into two groups: a control group and an experimental group. Rats of the experimental group were intraperitoneally injected with metoclopramide at a dose of 2.2mg/kg for 14 successive days to induce hyperprolactinemia. The control group was injected with saline in the same manner. Hormonal assays for serum prolactin and testosterone levels were carried out. Prostate was extirpated and the lateral lobes were processed for examination by light and electron microscopy. Epithelial height of the prostatic lateral lobes acini was determined morphometrically and analyzed statistically. Results In the experimental hyperprolactinemic group, numerous prostatic acini were lined by multiple layers of epithelial cells (hyperplasia). Acinar epithelium had different ultrastructural features. Some acini had pleomorphic nuclei, cytoplasmic vacuoles, and residual bodies. Others were packed with extensive cisternae of rough endoplasmic reticulum and secretory vesicles. Others had few secretory vesicles and the majority of them had centrally located flocculent material surrounded by electron-lucent zones. Some epithelial cells contained lipofuscin pigments. The prostatic epithelial lining was infiltrated by inflammatory cells. Stromal thickening was found in between some acini that was surrounded by prominent smooth muscle cells and many connective tissue cells. Hormonal assays showed increased serum prolactin and decreased testosterone as compared with the control group. The estimated and analyzed epithelial height of the prostatic acini showed a highly significant increase compared with the control group. Conclusion Hyperprolactinemia altered the morphology of epithelium and stroma of the prostate lateral lobe. It played a significant role in inducing a prostatic hyperplasia and an inflammatory response that triggered the abnormal growth of prostate.