TY - JOUR
T1 - The effect of oophorectomy on mechanical properties of rabbit cerebral and coronary isolated small arteries
AU - Hansen, V. B.
AU - Skajaa, K.
AU - Aalkjaer, C.
AU - Oxlund, H.
AU - Glavind, E. B.
AU - Petersen, O. B.
AU - Forman, A.
PY - 1996
Y1 - 1996
N2 - OBJECTIVE: Our purpose was to study the effect of oophorectomy on the passive and active mechanical characteristics of rabbit small cerebral and small coronary arteries. STUDY DESIGN: Ring preparations of small cerebral and small coronary arteries from rabbits that had undergone oophorectomy and sham operation were mounted on myographs 6 weeks after operation. Experiments were performed as follows. (1) concentration-response relations for vasopressin (10-11 to 10-7 mol/L), U46619 (10-10 to 10-6 mol/L), 5- hydroxytryptamine (10-7 to 10-5 mol/L), and endothelin (10-13 to 10- 7 mol/L); (2) relaxing effects of acetylcholine (10-8 to 10-4 mol/L); (3) length-tension relations after addition of high potassium (124 mmol/L), vasopressin (10-7 mol/L), and a mixture composed of potassium (124 mmol/L), vasopressin (10-7 mol/L), and prostaglandin F(2α) (10-5 mol/L); (4) calculation of vessel morphologic features and determination of hydroxyproline as a measure of collagen content. RESULTS: Oophorectomy did not influence basal tone, relaxant effects of acetylcholine, vessel morphologic features, elastic characteristics, or hydroxyproline content of the vessels. However, in cerebral arteries at a normalized lumen diameter, oophorectomy induced a marked increase in the force development after stimulation with agonists but not after depolarization with high potassium. The reason for this was a leftward shift in the active length-tension curves (vasopressin activation). In coronary arteries none of these changes were seen after oophorectomy. CONCLUSION: These data demonstrate that withdrawal of ovarian hormones changes the position of the active length-tension curve for pharmacomechanical but not electromechanical coupling of small cerebral arteries without interference with the elastic characteristics of these vessels.
AB - OBJECTIVE: Our purpose was to study the effect of oophorectomy on the passive and active mechanical characteristics of rabbit small cerebral and small coronary arteries. STUDY DESIGN: Ring preparations of small cerebral and small coronary arteries from rabbits that had undergone oophorectomy and sham operation were mounted on myographs 6 weeks after operation. Experiments were performed as follows. (1) concentration-response relations for vasopressin (10-11 to 10-7 mol/L), U46619 (10-10 to 10-6 mol/L), 5- hydroxytryptamine (10-7 to 10-5 mol/L), and endothelin (10-13 to 10- 7 mol/L); (2) relaxing effects of acetylcholine (10-8 to 10-4 mol/L); (3) length-tension relations after addition of high potassium (124 mmol/L), vasopressin (10-7 mol/L), and a mixture composed of potassium (124 mmol/L), vasopressin (10-7 mol/L), and prostaglandin F(2α) (10-5 mol/L); (4) calculation of vessel morphologic features and determination of hydroxyproline as a measure of collagen content. RESULTS: Oophorectomy did not influence basal tone, relaxant effects of acetylcholine, vessel morphologic features, elastic characteristics, or hydroxyproline content of the vessels. However, in cerebral arteries at a normalized lumen diameter, oophorectomy induced a marked increase in the force development after stimulation with agonists but not after depolarization with high potassium. The reason for this was a leftward shift in the active length-tension curves (vasopressin activation). In coronary arteries none of these changes were seen after oophorectomy. CONCLUSION: These data demonstrate that withdrawal of ovarian hormones changes the position of the active length-tension curve for pharmacomechanical but not electromechanical coupling of small cerebral arteries without interference with the elastic characteristics of these vessels.
KW - Cerebral arteries
KW - coronary arteries
KW - length- tension relations
KW - ovarian hormone withdrawal
KW - rabbit
U2 - 10.1016/S0002-9378(96)70040-6
DO - 10.1016/S0002-9378(96)70040-6
M3 - Journal article
C2 - 8942500
AN - SCOPUS:0029912010
SN - 0002-9378
VL - 175
SP - 1272
EP - 1280
JO - American Journal of Obstetrics and Gynecology
JF - American Journal of Obstetrics and Gynecology
IS - 5
ER -