Postnatal Development of Brain Natriuretic Peptide-immunoreactive Neuron in the Hypothalamus of the Rat / 체질인류학회지

ABSTRACT

Brain natriuretic peptide (BNP) is a neuropeptide, isolated from porcine brain that is homologous with atriopeptin. Magnocellular neurosecretory cells located in the paraventricular nucleus and supraoptic nucleus synthesize and secrete neurohormones. The purpose of this study was to investigate distribution of BNP immunoreactivity throughout the rat hypothalamus from the day of birth to 30 days and adult using immunoperoxidase and immunofluorescent staining. The first BNP immunoreactive neurons appeared in the paraventricular and supraoptic nucleus at P10. In adult, BNP immunoreactivity was widely distributed throughout regions of the hypothalamus including dorsomedial hypothalamic nucleus, ventromedial hypothalamic nucleus, arcuate nucleus and internal layer of median eminence. The intensity of BNP immunoreactivity was weak in almost all hypothalamic nuclei except the paraventricular and supraoptic nuclei. BNP immunoreactivity was first observed in the lateral hypothalamic area at P15. In retrochiasmatic supraoptic nucleus, BNP immunoreactivity was first observed at P20 and remarkably distributed in adult. In the present study, distinct localization of BNP immunoreactivity was in the hypothalamic cell bodies and fibers. Although the role of BNP in the brain is yet to be determined, these results indicate that BNP in the neurons of hypothalamus play important role in the regulation of a variety of neurosecretory functions as a neuromodulator during postnatal development of the hypothalamus.