[Reinterpretation of the Malpighian body in light of the existence of a single glomerular arteriole (Trabucco and Marquez)]

Abstract

Introduction: In 1842 William Bowman described the microvascular system of the Malpighian body. Electron microscopic studies definitively revealed the spatial structure of its mesangial-capillary-epithelial component. In 1952-54 Trabucco and Marquez challenged the ideas of Bowman, demonstrating the existence of a single glomerular arteriole. Our study supports the finding of a single glomerular arteriole, leading to a definitive interpretation of the Malpighian body structure.

Materials and methods: Serial histological studies were carried out of the vascular pole in a case of oligomeganephrotic renal hypoplasia and the immunohistochemical study of embryonal glomerular development (15 embryos aged between 7 and 11weeks), with alpha-actin (smooth muscle marker), CD31 and CD34 (endothelial markers) and CD10 (podocyte marker).

Results: The study of the glomerular vascular pole in the case of oligomeganephrotic renal hypoplasia supports the existence of a single glomerular arteriole. Our immunohistochemical study confirmed this finding and provided data on the morphogenesis of the mesangial-capillary-epithelial component of the Malpighian body.

Conclusions: There exist a single glomerular arteriole. Mesangial and endothelial cells originating from a single glomerular arteriole interact with an epithelial component derived from the nephrogenic vesicle which then generate the lobular glomerular tuft, providing the basis for a definitive interpretation of the structure of the Malpighian body. There is no scientific base to the interpretation of the glomerular microvascular system as having two glomerular arterioles with an intercalated capillary network.

Keywords: Arteriola glomerular única; Corpúsculo de Malpighi; Malpighian body; Microvascular system; Single glomerular arteriole; Sistema microvascular del corpúsculo de Malpighi.