Effects of chronic in vivo .BETA.-adrenergic stimulation on rat adipocytes: Lipolysis and the characteristics of .BETA.-adrenergic receptors in exercise-trained and chronic isoproterenol-treated rats.
- VernacularTitle:ラット脂肪細胞に及ぼすｉｎ ｖｉｖｏの連続的なカテコールアミン刺激の影響 トレーニングラットならびにイソプロテレノール連続投与ラットにおける脂肪分解とアドレナリン受容体
- Author:
TETSUYA IZAWA
;
TAKAO KOMABAYASHI
;
KAZUHIRO SUDA
;
EIZI KOSHIMIZU
;
MINORU TSUBOI
- Publication Type:Journal Article
- Keywords:
training;
chronic isoproterenol-treatment;
rat adipocytes;
lipolysis;
β-adrenergic receptor
- From:Japanese Journal of Physical Fitness and Sports Medicine
1987;36(3):147-155
- CountryJapan
- Language:Japanese
-
Abstract:
The present study was designed to provide more extensive information on the effects of chronic in vivo β-adrenergic stimulation as produced in two different fashions, one through exercise training and the other through the chronic administration of isoproterenol, on the characteristics of β-adrenergic receptors (β-AR) in rat adipocyte membranes.
1. The chronic administration of isoproterenol (2.5 mg/kg BW sc, daily for 21 days; IPR-treatment) significantly reduced lipolysis induced by noradrenaline in isolated adipocytes. However, exercise training (8 weeks of treadmill running) significantly increased the lipolytic response of adipocytes to noradrenaline.
2. IPR-treatment significantly decreased the percentage of the high affinity state (%RH) and increased the dissociation constants of the high affinity state (KH) of β-AR in computer modeling of (-) -noradrenaline competition curves. However, exercise training significantly increased %RH.
In conclusion, IPR-treatment reduced the lipolytic response of adipocytes to noradrenaline, at least partially, which resulted in the decreased formation of the high affinity state of β-AR. Exercise training may enhance the lipolytic ability of adipocytes to catecholamines through facilitating the formation of the high affinity state of β-AR.
