Js. Lacroix et al., SYMPATHETIC AND PARASYMPATHETIC INTERACTION IN VASCULAR CONTROL OF THE NASAL-MUCOSA IN ANESTHETIZED CATS, Journal of physiology, 480, 1994, pp. 325-331
1. In cats anaesthetized with pentobarbitone sodium (45 mg kg(-1)), el
ectrical stimulation of the parasympathetic nerve fibres to the nasal
mucosa evoked frequency-dependent increases in nasal arterial blood fl
ow whereas stimulation of the superior cervical sympathetic nerve indu
ced marked vasoconstriction. 2. Sympathetic nerve stimulation for 3 mi
n at 10 Hz evoked significant (P < 0.05) and prolonged (> 30 min) atte
nuation of the vasodilatory response to subsequent parasympathetic sti
mulation. 3. Combined pretreatment with adrenergic and cholinergic blo
ckers reduced the vasoconstrictory effect of sympathetic stimulation b
y 28 +/- 4% (mean +/- S.E.M.) and the parasympathetically evoked vasod
ilatation by 20 +/- 5%. 4. The vasodilatory effects of exogenous vasoa
ctive intestinal polypeptide, peptide histidine isoleucine and galanin
, and the vasoconstrictory effects of exogenous neuropeptide Y (NPY) a
nd alpha,beta-methylene adenosine 5'-triphosphate were not altered by
adrenoceptor antagonists and atropine whereas the effects of exogenous
noradrenaline and acetylcholine mere virtually abolished. 5. The atro
pine-resistant parasympathetic vasodilatation remained significantly a
ttenuated for more than 30 min after the non-adrenergic sympatheticall
y evoked vasoconstriction. 6. Exogenous NPY (25 x 10(-9) mol) mimicked
the effect of sympathetic stimulation in attenuating subsequent paras
ympathetically evoked vasodilatation.