Premium
Electrically induced vasomotor responses and their propagation in rat renal vessels In vivo
Author(s) -
Steinhausen Michael,
Endlich Karlhans,
Nobiling Rainer,
Parekh Niranjan,
Schütt Florian
Publication year - 1997
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1997.493bb.x
Subject(s) - vasomotor , depolarization , vasodilation , vasoconstriction , stimulation , in vivo , pipette , anatomy , biophysics , chemistry , medicine , biology , microbiology and biotechnology
1 Vasomotor responses (VMR) induced by local electrical stimulation were studied in the vasculature of the split hydronephrotic rat kidney by in vivo microscopy. 2 Unipolar pulses, which were applied by a micropipette positioned close to the vessel wall, elicited local and propagated VMR. Depolarizing and hyperpolarizing currents caused vaso‐constriction and vasodilatation, respectively. 3 The magnitude of VMR could be controlled within seconds by variation of pulse frequency, pulse width and voltage. VMR were abolished by slight retraction of the stimulating micro‐pipette. Repetitive electrical stimulation resulted in reproducibly uniform VMR. 4 Propagated VMR decayed with increasing distance from the stimulation site. They decayed more rapidly in the upstream than in the downstream flow direction in interlobular arteries. The longitudinal decay was well approximated by an exponential function with significantly different length constants of 150 ± 40 μ m (upstream, n = 5 ) and 420 ± 90 μ m (downstream, n =8). 5 Our results show that vasomotor responses, which are initiated by changes in membrane potential, are propagated over distances of potential physiological importance in interlobular arteries.