[Vasoactivity of human nasal mucosa in response to sensory neurotransmitters (a study of nasal geometrical change with acoustic rhinometry)].
Intranasal blood flow is regulated not only by autonomic but also by sensory nervous systems. Sensory neurotransmitters are reported to control resistance vessels. Our investigation of intranasal vasoactivity before and after applying sensory neurotransmitters was conducted using acoustic rhinometry. Acoustic rhinometry is a modern method of evaluating the cross-sectional area and volume of the nasal cavity. Its characteristics are that it is a non-traumatic procedure, minimal time is required for measurements and reliability is high. In the present experiment, calcitonin gene-related peptide (CGRP) and substance P (SP) were used as the sensory neurotransmitters. Six males (26-39 years old), without nasal abnormalities, were examined for one hour with acoustic rhinometry before and after administration of these transmitters. Nose drops of these preparations were introduced into one nasal cavity of each candidates, while in the head tilt position. After application of nose drops, both sides were evaluated with acoustic rhinometry in regard to minimal cross sectional area (MCSA) and nasal volume. Both CGRP and SP decreased the MCSA and volume on the applied side within ten minutes, which was followed by a plateau level for 1 hour. The opposite sides showed no significant change in either MCSA or volume. Changes in the MCSA ratio increased dose-dependently as the concentration of CGRP or SP increased. Changes in the volume ratio decreased when the concentration of SP was increased from 10(-8) to 10(-7) M, while it converted and then rose at 10(-6) M. CGRP has a potent vasodilator effect on vascular smooth muscles. SP also induces relaxation of vascular tone via endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Tanaka
T
T
Department of Otolaryngology, Tokyo University Branch Hospital.
Kase
Y
Y
Okita
W
W
Ichimura
K
K
Iinuma
T
T
D000328:Adult; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009296:Nasal Cavity / Q000033:anatomy & histology*; D009297:Nasal Mucosa / Q000098:blood supply*; D013373:Substance P / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*
D013373:Substance P; D015740:Calcitonin Gene-Related Peptide