Open AccessDifferences in Vasomotor Responses Between Main Stem and Smaller Branches of the Human Uterine Artery
Author(s) -
Ekström Per,
Alm Per,
Åkerlund Mats
Publication year - 1991
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.3109/00016349109007155
Subject(s) - oxytocin , uterine artery , medicine , endocrinology , vasopressin , angiotensin ii , atrial natriuretic peptide , endothelin receptor , endothelin 1 , artery , renin–angiotensin system , prostaglandin , blood pressure , biology , receptor , pregnancy , gestation , genetics
Specimens of the human uterine artery and its branches were taken at hysterectomy. By microscopical dissection, three groups of arteries were obtained with respect to size ‐main stem, medium and small branches (inner diameters of >1, 0.6‐0.8 and <0.4 mm, respectively). The contractile effects of different vasoactive substances were studied and the responses expressed as percentages of that of K ± ‐depolarization calculated. The most potent vasoconstrictor (the lowest EC 50 concentration) was arginine vasopressin (AVP) followed in order by endothelin, oxytocin, prostaglandin (PG)F 2α , noradrenalin and dopamine. Angiotensin had inconsistent effects. Atrial natriuretic peptide (ANP) counteracted the contractile effects of endothelin. AVP, endothelin, oxytocin and noradrenalin were significantly more potent on the smallest branches than on the main stem of the artery. Since the former type of vessel represents resistance arteries, the present results suggest that AVP, endothelin, oxytocin and noradrenalin could be of specific importance in the regulation of uterine blood flow. PGF 2α , dopamine and angiotensin appear to be of minor importance from this aspect but ANP could play a role by regulating the effects of endothelin.