Abstract
Human omental arteries and veins are supplied with nerve fibers containing noradrenaline (NA) and neuropeptide Y (NPY); these two agents probably co-exist in perivascular sympathetic nerve fibers. Substance P (SP)- or vasoactive intestinal peptide (VIP)-containing fibers could not be detected. In studies on isolated omental vessels NA produced constriction. The results of blockade experiments suggest that human omental arteries are equipped predominantly with α1-adrenoceptors and omental veins with a mixture of α1- and α2-adrenoceptors. NPY at a concentration of 10-7 M or higher had a weak contractile effect on veins and virtually no effect on arteries. NPY at a concentration of 3 × 10-8 M shifted the NA concentration response curve to the left in arteries (pD2 = 5.8 for NA versus 6.6. for NA in the presence of NPY; P < 0.001) but not in veins. Both SP and VIP relaxed arteries precontracted with NA or prostaglandin F2α (PGF2α). The potency of SP as a relaxant agent was similar in arteries and veins; the effect of VIP was elicited at lower concentrations in veins than in arteries.
Original language | English (US) |
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Pages (from-to) | 67-79 |
Number of pages | 13 |
Journal | Regulatory Peptides |
Volume | 12 |
Issue number | 1 |
DOIs | |
State | Published - Sep 1985 |
Externally published | Yes |
Keywords
- arteries and veins
- neuropeptides
- noradrenaline
- sympathetic nerves
- vasomotor response
ASJC Scopus subject areas
- Biochemistry
- Endocrinology
- Physiology
- Neuroscience(all)