Elevated contractile responses to acetylcholine in organ cultured rabbit carotid artery.
The aim of the present study was to examine the functional changes that occur when a rabbit carotid artery is cultured in serum-free medium. In endothelium (EC)-intact arteries cultured under serum-free conditions, acetylcholine (ACh)-induced relaxation responses were partially, yet significantly, reduced when compared with freshly isolated arteries. After pretreatment with NG-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, application of ACh resulted in a significant contraction in organ cultured arteries. The amplitude of the ACh-induced contractions increased with the duration of culture. In EC-denuded arteries cultured under serum-free conditions, ACh induced responses similar to those in EC-intact arteries pretreated with L-NAME. Furthermore, ACh caused a significant increase in intracellular Ca2+ concentration ([Ca2+]i) in EC-denuded arteries cultured under serum-free condition for 7 days. There was little change in either [Ca2+]i or tension in freshly isolated carotid rings. There was no difference in sodium nitroprusside-induced relaxation responses between fresh and cultured arteries. These results suggest that prolonged culture of carotid arteries under serum- free conditions changes the functional properties of vascular reactivity in rabbit carotid arteries.
Lee
Youngho
Y
Department of Physiology, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea.
Jung
Seungsoo
S
Won
Jong-Eun
JE
Nam
Taiksang
T
Ahn
Ducksun
D
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002339:Carotid Arteries / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D016895:Culture Media, Serum-Free / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015233:Models, Statistical; D009119:Muscle Contraction; D019331:NG-Nitroarginine Methyl Ester / Q000378:metabolism / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D009924:Organ Culture Techniques / Q000379:methods*; D011817:Rabbits; D013997:Time Factors
D016895:Culture Media, Serum-Free; D009599:Nitroprusside; D000109:Acetylcholine; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester