[Cell paracrine communities: physiology, clinical biochemistry and diagnosis of impaired functions (a lecture)]

The paper describes the author's opinion that the phylogenetic system of multicellular organisms occurs on the route: unicellular organisms (cells) --> a cell paracrine community (the structural and functional unit of future organs)--> an organ --> a system of organs. All humorally, paracrinally regulated communities consist of (a) cells with specific function and (b) a peristaltic pump for perfusion (homeostatic function) and c) loose connective tissue cells for the biological function of the endoenvironmen. The peristaltic pump comprises a monolayer of the endothelium and smooth muscle cells; the humoral regulators of its enhanced function (a direct association) include nitric oxide, nitrites and nitrates, the peptide endothelin and prostacyclins. In the communities of the kidneys, lungs, and brain, the pumps work through local hydrodynamic parameters; feedback mechanisms, such as angiotensinogen, renin, angiotensin-converting enzyme and angiotensin II, regulate the lowering of pump function. Local pumps are pooled into the closed circulatory system in later phylogenetic steps when the function of locomotion (movement). At the same time, elastic-type arteries and the heart (the central pump), the proximal arterial bed, are formed; the peripheral pumps form a phylogenetically ancient distal portion. Under these conditions, the paracrine communities simultaneously realize local and central regulation from the level of the vasomotor center (autonomic innervation) and two regulations are not always coordinated. Enhanced central regulation forces the paracrine communities to activate the feedback mechanisms; angiotensin II is a humoral feedback mediator in the paracrine communities.