Sympathetic and parasympathetic interaction in vascular control of the nasal mucosa in anaesthetized cats.
1. In cats anaesthetized with pentobarbitone sodium (45 mg kg-1), electrical stimulation of the parasympathetic nerve fibres to the nasal mucosa evoked frequency-dependent increases in nasal arterial blood flow whereas stimulation of the superior cervical sympathetic nerve induced marked vasoconstriction. 2. Sympathetic nerve stimulation for 3 min at 10 Hz evoked significant (P < 0.05) and prolonged (> 30 min) attenuation of the vasodilatory response to subsequent parasympathetic stimulation. 3. Combined pretreatment with adrenergic and cholinergic blockers reduced the vasoconstrictory effect of sympathetic stimulation by 28 +/- 4% (mean +/- S.E.M.) and the parasympathetically evoked vasodilatation by 20 +/- 5%. 4. The vasodilatory effects of exogenous vasoactive intestinal polypeptide, peptide histidine isoleucine and galanin, and the vasoconstrictory effects of exogenous neuropeptide Y (NPY) and alpha,beta-methylene adenosine 5'-triphosphate were not altered by adrenoceptor antagonists and atropine whereas the effects of exogenous noradrenaline and acetylcholine were virtually abolished. 5. The atropine-resistant parasympathetic vasodilatation remained significantly attenuated for more than 30 min after the non-adrenergic sympathetically evoked vasoconstriction. 6. Exogenous NPY (25 x 10(-9) mol) mimicked the effect of sympathetic stimulation in attenuating subsequent parasympathetically evoked vasodilatation.
Lacroix
J S
JS
Prince of Wales Medical Research Institute, Prince of Wales Hospital, Sydney, NSW, Australia.
Ulman
L G
LG
Potter
E K
EK
D000109:Acetylcholine / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D005260:Female; D008297:Male; D009297:Nasal Mucosa / Q000098:blood supply* / Q000187:drug effects / Q000294:innervation*; D009478:Neuropeptide Y / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D009478:Neuropeptide Y; D014660:Vasoactive Intestinal Peptide; D000109:Acetylcholine; D009638:Norepinephrine