Glomerular microcirculation: Implications for diabetes, preeclampsia, and kidney injury

Abstract

This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow. Multiple points of cooperation exist between autoregulatory and distributional mechanisms. Mutual interactions between myogenic and tubuloglomerular feedback (TGF) mechanisms regulating the inflow are briefly discussed. In addition to this, TGF operation involving purinergic, autocoid, and NO signaling affects, however, not only afferent arteriolar tone, but mesangial cell tone as well. The latter reversibly reconfigures the distribution of blood flow between the shorter and longer pathways in the glomerular tuft. I advance a hypothesis that blood flow in these pathways spontaneously alternates, and mesangial cell tonicity serves as a rheostatic shift between them. Furthermore, humoral messengers from macula densa cells, themselves dependent on myogenic mechanisms, fine‐tune the secretion of renin and, subsequently, the local, intrarenal generation of angiotensin II, which, in turn, provides additional vasomotor signaling to glomerular capillaries through changing the tone of mesangial cells. This complex regulatory network may partially explain the phenomenon of renal functional reserve, as well as suggest implications for changes in renal function during pregnancy, early diabetes mellitus, and acute kidney injury.

The Impact of Disease Duration on Microcirculatory Dysfunction in Young Patients with Uncomplicated Type 1 Diabetes

“…In fact, the earliest symptoms of cardiovascular diseases appear in microcirculation, especially those related to inflammation [9,28]. Microvascular abnormalities are found in conditions like diabetes [3,29], renal disorders [30], cardiovascular disorders [31][32][33] like hypertension [34][35][36] or systemic connective tissue disorders [2], septic shock [37], and hypoxia [38]. They primarily lead to flow abnormalities, which are associated with impaired tissue oxygenation and organ damage and hurt prognosis [33,36].…”

Use of Renal Replacement Therapy in Pregnant Women with Acute Kidney Injury or Chronic Kidney Disease: A Systematic Review

“…[23][24][25] The multiple changes in renal physiology during pregnancy make it difficult to define Pr-AKI. 19,26 All pregnant patients at risk of AKI should have a detailed medical history with a complete physical examination and laboratory tests for a timely diagnosis. 13,19,20,27 Renal echography, specific laboratory tests, and renal biopsy are reserved when the diagnosis is not clear.…”

Recent advances in kidney research

“…In addition to original research articles, several recent review articles highlight developments in renal physiology and pathophysiology pertaining to physiological feedback loop mechanisms, such as glomerular crosstalk mechanisms and circadian rhythm. Firstly, 17 hypothesizes that the complex regulatory network around the regulation of glomerular microcirculation contributes to renal functional reserve and is affected in physiological processes such as renal function during pregnancy as well as developing diabetes mellitus and acute kidney injury. Mesangial cells, having been proposed to both remove pathogens from the glomerulus and deposit extraglomerular material, contribute to renal cellular immune responses and glomerular cell‐to‐cell signaling, 18 are notably important mediators of glomerular crosstalk 19 .…”