Publications by authors named "Wolfgang Freisinger"

Renal denervation (DNX) is a treatment for resistant arterial hypertension. Efferent sympathetic nerves regrow, but reinnervation by renal afferent nerves has only recently been shown in the renal pelvis of rats after unilateral DNX. We examined intrarenal perivascular afferent and sympathetic efferent nerves after unilateral surgical DNX.

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Recently, we showed that renal afferent neurons exhibit a unique firing pattern, i.e., predominantly sustained firing, upon stimulation.

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Sensory neurons with afferent axons from the kidney are extraordinary in their response to electrical stimulation. More than 50% exhibit a tonic firing pattern, i.e.

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Other than efferent sympathetic innervation, the kidney has peptidergic afferent fibers expressing TRPV1 receptors and releasing substance P. We tested the hypothesis that stimulation of afferent renal nerve activity with the TRPV1 agonist capsaicin inhibits efferent renal sympathetic nerve activity tonically by a neurokinin 1 receptor-dependant mechanism. Anesthetized Sprague-Dawley rats were instrumented as follows: (1) arterial and venous catheters for recording of blood pressure and heart rate and drug administration; (2) left-sided renal arterial catheter for selective intrarenal administration of the TRPV1 agonist capsaicin (3.

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Article Synopsis
  • Sympathetic efferent and peptidergic afferent renal nerves may play a role in hypertensive and inflammatory kidney diseases.
  • Recent studies using confocal microscopy show that sympathetic nerve endings in the kidney are located near afferent nerve fibers, suggesting potential interaction between these nerve types.
  • Experiments revealed that norepinephrine (NE) decreases calcium currents in renal neurons, indicating that sympathetic nerve activity can influence the function of renal afferent nerves, with specific adrenergic receptors mediating this effect.
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Peptidergic afferent renal nerves (PARN) have been linked to kidney damage in hypertension and nephritis. Neither the receptors nor the signals controlling local release of neurokinines [calcitonin gene-related peptide (CGRP) and substance P (SP)] and signal transmission to the brain are well-understood. We tested the hypothesis that PARN, compared with nonrenal afferents (Non-RN), are more sensitive to acidic stimulation via transient receptor potential vanilloid type 1 (TRPV1) channels and exhibit a distinctive firing pattern.

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Sensory nerve fibers from the dorsal root ganglia (DRG) may contribute to the regulation of peripheral vascular resistance. Axons of DRG neurons of the lower thoracic cord project mainly to resistance vessels in the lower limbs, likely opposing the vasoconstrictor effects of the sympathetic activity. This mechanism might be of importance in hypertension with increased sympathetic activity.

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