An ultrastructural study of the endonasal microcirculation in the Wistar rat during fetal and early postnatal life

Fenestrated capillaries were observed prenatally in the lateral nasal wall and in glandular capillaries of the nasal mucosa of the rat. The number of fenestrations increased towards full term and during postnatal life. Specific ultrastructural features in the vascular bed were found to be primarily determined in utero.