Zusammenfassung
Hintergrund: Endogen produziertes Stickoxid (NO) spielt eine wichtige Rolle für die Gefäßphysiologie
in verschiedenen Geweben des Menschen und anderer Spezies. Dabei geht man heute von
der dualen Regulation des Gefäßmuskeltonus durch NO als Neurotransmitter und endothelial
freigesetzten Botenstoff aus. Methode: Im Rahmen dieser Studie wurde die Verteilung der endothelialen konstitutiven NO-Synthase
(ecNOS) in der unteren Nasenmuschel des Menschen (n = 15) mit immunhistochemischen
Methoden dargestellt, um daraus Rückschlüsse auf Bedeutung und Wirkungsweise der NO-Produktion
in verschiedenen Gefäßendothelien der Nasenschleimhaut zu ziehen. Ergebnisse: Positive Immunreaktionen wurden in den Endothelzellen von Arteriolen, Kapillaren
und postkapillären Venolen, nicht aber in den venösen Sinus gefunden. Schlußfolgerungen: Diese Ergebnisse lassen den Rückschluß zu, dass unter physiologischen Bedingungen
endothelial produziertes NO in der Nasenschleimhaut des Menschen vor allem auf den
arteriellen Schenkel des Gefäßsystems einwirkt, aber auch für die Extravasation von
Serumbestandteilen eine wichtige Rolle spielt.
Summary
Background: Human nasal mucosa is a highly regulated tissue that performs a wide ränge of physiological
functions. In addition to the classic and peptidergic neurotransmitters, the endogenously
produced free radical gas nitric oxide (NO) has been found to be increasingly important
for the vascular regulation of this tissue. NO-dependent control of vascular tone
works in two ways, consisting of neurally produced NO acting as a neurotransmitter
on the one hand and endothelially produced NO on the other hand. Neurons and endothelial
cells contain various isoforms of the enzyme nitric oxide synthase, which forms NO
out of L-arginine. The aim of this study was to examine the distribution of endothelial
constitutive NO-synthase (ecNOS) in the human nasal mucosa of inferior turbinates.
Methods: Immunocytochemistry (avidin-biotin method) with polyclonal and monoclonal antibodies
against eNOS and Cluster of differentiation 31, a marker for endothelial and certain
blood cells, was used in order to gain more detailed information on the physiological
distribution and significance of NOS in vascular endothelium of different vessel types.
Results: Positive eNOS-immunoreactions were found in the endothelial cells of arterial blood
vessels of different diameters as well as in capillaries and postcapillary venules.
Venous sinuses with or without subendothelial cushions did not show any immunoreactions.
Conclusions: There is strong evidence that vascular tone in human nasal mucosa is not only subject
to nerval control, but also influenced directly by mediators released from the endothelium.
The present results lead to the conclusion that in physiological conditions endothelially
produced NO has an influence on the arterial component of the swelling mechanism in
human nasal mucosa. Because eNOS could also be detected in capillaries and postcapillary
venules, NO might also play an important role in plasma extravasation.
Schlüsselwörter
Nasenschleimhaut - Endothel - Gefäßtonus - Stickoxid (NO) - Endotheliale konstitutive
NO-Synthase (ecNOS)
Key words
Nasal mucosa - Endothelium - Vascular tone - Nitric oxide (NO) - Endothelial constitutive
nitric oxide synthase (ecNOS)
