title: Age-related changes in thoracic aorta of obese Zucker rats.
abstract: Studies were performed on the ontogeny of arterial blood pressure and functional properties of the thoracic aorta in lean (L) and obese (O) male Zucker rats at ages of 6-36 wk. Body weight was larger in the O than the L at all ages, with differences reaching values of 200-250 g at ages over 24 wk (at 33-36 wk: L = 510 +/- 9 and O = 730 +/- 15 g). Systolic blood pressure was lower in young O compared with L (6-15 wk) but increased with age at a rate seven times greater in O than in L. For ages of 33-36 wk, systolic pressure was significantly higher in O compared with L (O = 132 +/- 2 vs. L = 122 +/- 2 mmHg). Total serum cholesterol (at 36 wk: L = 278 +/- 31 and O = 354 +/- 12 mg/dl) and triglycerides (at 36 wk: L = 493 +/- 71 and O = 1,618 +/- 220 mg/dl), as well as glucose levels, increased with age in both groups and were significantly higher in O at all ages. Serum levels of thyroxine but not triiodothyronine were significantly lower in O at all ages. No differences were found in passive mechanics at any age. Values of maximum active stress with smooth muscle activation by 75 mM K+ plus 10 microM norepinephrine were significantly higher at 24 and 36 wk in O (at 36 wk: L = 573 +/- 42 and O = 821 +/- 89 x 10(3) dyn/m2).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Bockus Research Institute, Graduate Hospital, University of Pennsylvania School of Medicine, Philadelphia 19146.
authors.forename: R H
authors.initials: RH
authors.lastname: Cox
authors.forename: D C
authors.initials: DC
authors.lastname: Kikta
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology / Q000503:physiopathology*; D001794:Blood Pressure; D001835:Body Weight; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D009765:Obesity / Q000503:physiopathology*; D009929:Organ Size; D009994:Osmolar Concentration; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011924:Rats, Zucker; D012701:Serotonin / Q000494:pharmacology; D013314:Stress, Mechanical; D014664:Vasodilation / Q000502:physiology
chemical_list: D009569:Nitric Oxide; D012701:Serotonin; D011188:Potassium; D009638:Norepinephrine