Commentaries on the publication entitled Evidence for continuity of interstitial spaces across tissue and organ boundaries in humans

TL;DR

This paper discusses the continuity and systemic flow of interstitial fluid across tissue boundaries, supported by microscopic particle movement and hyaluronic acid distribution, challenging the idea of isolated interstitial spaces.

Contribution

It provides evidence for the long-distance flow of interstitial fluid through fibrous tissues, suggesting a systemic circulation mechanism across tissues and organs.

Findings

Micron-sized particles cross tissue boundaries, indicating fluid movement.

Distribution of hyaluronic acid suggests continuous interstitial pathways.

Interstitial spaces lack distinct spatial structure for free fluid flow.

Abstract

Interstitial connective tissues are one of the four basic types of animal tissue and continuously distributed throughout the body. Illustrated by the movements of the micron-sized particles across the defined tissue boundaries and the continuously distributions of the fluorescently stained hyaluronic acid within the fibrous tissues around blood vessels and nerves, the authors of this paper suggested that interstitial fluid (ISF) is not fixed locally but would flow through fibrous matrices for a long-distance, even between more distant parts of the body. However,the fluid-filled interstitial spaces are similar with the interstitial tissue channel, lacking a distinct spatial structure for "free" interstitial fluid flow, which might be the key to comprehend the whereabouts and directions of a systemic fluid flow and circulation.