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DIFFERENCES IN ENDOTHELIUM‐DEPENDENT RELAXATION IN VARIOUS ARTERIES FROM WATANABE HERITABLE HYPERLIPIDAEMIC RABBITS WITH INCREASING AGE
Author(s) -
Kitagawa Satomi,
Yamaguchi Yu,
Sameshima Emiko,
Kunitomo Masaru
Publication year - 1994
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1994.tb02658.x
Subject(s) - endothelium , cardiology , medicine , vasodilation , endocrinology
SUMMARY 1. Endothelium‐dependent relaxation in response to acetylcholine (ACh) and the calcium ionophore A 23187 was examined in aorta, coronary, basilar and renal arteries isolated from Watanabe heritable hyperlipidaemic (WHHL) rabbits of 2, 6 and 12 months of age, with normolipidaemic heterozygous WHHL rabbits as controls. 2. In the rings of WHHL rabbit aortae and coronary arteries preconstricted with vasoconstrictors, endothelium‐dependent relaxation in response to ACh was attenuated with age compared to the heterozygous WHHL rabbits. A significant negative correlation was found between the total cholesterol content and the relaxation response to ACh in the aortae or coronary arteries from 6 and 12 month old WHHL rabbits. 3. In the rings of basilar arteries, endothelium‐dependent relaxations to ACh were not modified with age. Similarly, in the rings of renal arteries, the relaxation response to ACh was not changed with age, but in the 6 and 12 month preparations, after the age of 6 months, a contraction following the relaxation appeared at higher concentrations of ACh (10 −7 to 10 −6 mol/L). The contraction was endothelium‐dependent and inhibited by indomethacin. 4. A 23187‐induced endothelium‐dependent relaxations were also markedly attenuated in the aorta and significantly in the coronary artery with age. 5. Endothelium‐independent relaxation to sodium nitroprusside was not changed in all arteries from WHHL rabbits of different ages. 6. These findings indicate that in the aorta and coronary artery of the WHHL rabbit, the endothelium‐dependent relaxation to ACh and A 23187 becomes impaired with increasing age (i.e., with the progression of cholesterol deposition in the arterial wall) but is preserved in the basilar and renal artery.