Levels of plasma neuropeptide Y and other vasoactive substances during head-up tilt in normal and essential hypertensive subjects.
Neuropeptide Y, a potent vasoconstrictor peptide with 36 amino acid residues, is co-stored and released with catecholamines in sympathetic nerve endings. In this study responses in circulating neuropeptide Y induced by baroreceptor activation during change from the supine to the head-up position was measured in normal subjects and untreated essential hypertensives. Furthermore, the relationships with plasma catecholamines, endothelin-1, renin and serotonin were studied. No significant differences of plasma neuropeptide Y were found between normotensive and hypertensive subjects, before or after postural changes, and there was no correlation with a range of the vasoactive substances studied. Our results suggest that plasma neuropeptide Y does not increase with noradrenaline on sympathetic activation during postural stress both in normals and in hypertensive subjects. In man, measurement of plasma neuropeptide Y during head-up tilt does not provide a useful estimation of sympathetic nervous activity.
Veglio
F
F
Department of Medicine and Experimental Oncology, University of Turin, Italy.
Schiavone
D
D
Mengozzi
G
G
Molino
P
P
Chiandussi
L
L
D000328:Adult; D002395:Catecholamines / Q000097:blood; D016232:Endothelins / Q000097:blood; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009478:Neuropeptide Y / Q000097:blood*; D011187:Posture / Q000502:physiology*; D012083:Renin / Q000097:blood; D012701:Serotonin / Q000097:blood
D002395:Catecholamines; D016232:Endothelins; D009478:Neuropeptide Y; D012701:Serotonin; D012083:Renin