title: Protective action of elastase on changes in mechanical properties of vascular smooth muscles during atherosclerogenesis in hypercholesterolemic rabbits.
abstract: Effects of oral administration of elastase on changes in contractile responses of smooth muscle cells of the aorta and pulmonary artery were studied in rabbits fed a high-cholesterol diet. In rabbits on high-cholesterol diet, the acetylcholine (ACh)-induced endothelium-dependent relaxation was gradually decreased, and over 10 weeks on this diet, the relaxing responses were diminished, abolished or converted to contraction, while contractions produced by high-potassium (high-K) were enhanced and those produced by noradrenaline (NA) were decreased in sensitivity. In tissues from aged rabbits (2-8 years old), the ACh-induced relaxation was decreased while sensitivity to NA or high-K was elevated, in comparison with findings in young rabbits (3-4 months old). Oral administration of elastase together with high-cholesterol diet inhibited decreases in the ACh-induced relaxation or the NA-contraction, but not the increase in high-K contraction. The elevated concentrations of cholesterol but not those of triglycerides in sera, were significantly lowered by elastase. These results provide evidence that elastase has a hypocholesterolemic action and a protective role in atherosclerosis.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D001161:Arteriosclerosis / Q000503:physiopathology*; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000097:blood; D004036:Diet, Atherogenic; D005260:Female; D006937:Hypercholesterolemia / Q000503:physiopathology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010196:Pancreatic Elastase / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000187:drug effects; D011817:Rabbits; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
chemical_list: D014280:Triglycerides; D002784:Cholesterol; D010196:Pancreatic Elastase; D000109:Acetylcholine; D009638:Norepinephrine