Slit-pore mechanism to control flow through a filter membrane.
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Animals↗
Biomedical subjects
W J Gatzek
Publications and source records attributed to W J Gatzek.
The elastic constraint effect: a possible factor in renal perfusion.
An elastic constraint placed onto a distensible conduit modifies its perfusion characteristics. Surprisingly, a manifold increase in throughflow occurs as the resistance further downstream is increased. This flow anomaly occurs within a certain operating range of resistance settings.
Animals↗
The Gamma Loop: a model of glomerular hemodynamics. Part II.
The "Gamma Loop" Part I compared a model of rubber tubing to the architecture of the glomerulus with emphasis placed on the observed relationship between the position of the outflow resistance clamp and the perfusion of the loop (1, 2). Part II describes the pressures observed in the different parts of the loop, as well as the effect of another outflow branch which imitates "filtration".
Arterioles↗
The gamma loop, a model of glomerular hemodynamics.
A model of rubber tubing which imitates the vascular system of the glomerulus shows two flow anomalies: Partially closing down a clamp at the outlet increases perfusion. An increase in input pressure reduces perfusion. These anomalies are used to explain regulation of renal perfusion and autoregulation.
Animals↗
A new concept of pre-eclampsia.
The outstanding features of pre-eclampsia are hypertension and impairment of renal function which are likely due to an agent released by the placenta. A new concept of renal hemodynamics permits the assumption that a placental substance which keeps the gravid uterus relaxed escapes into the general circulation and upon arrival at the kidney produces glomerular hypoperfusion. This, in turn, leads to reduced renal function and activation of the Renin-Angiotension system.
Female↗
A new concept of renal hemodynamics.
Observations which show that urine output can vary with changes in the contour of the pulse cure, that it can even increase while the mean blood pressure falls during counterpulsation, that the well known hypertensive effect of a renal artery stenosis can also be produced by an aneurysm of the renal artery, cannot be explained by orthodox concepts of renal hemodynamics. The anatomical fact that the afferent glomerular arteriole is about twice as large as the efferent has so far not been adequately explained. The hypothesis that the combination of pulsatile flow and the unique anatomical configuration of the glomerulus permit a hydraulic switching mechanism which modifies profoundly its perfusion explains these questions.
Arterioles↗