Effects of the perfusion of beta-, beta2-, or beta3-adrenergic agonists or epinephrine on in situ adipose tissue lipolysis measured by microdialysis in underfed ewes.
The effects of isoproterenol (ISO, a non-selective beta-agonist), terbutaline (TER, a selective beta2-agonist), CL316243 (CL, a selective beta3-agonist), and epinephrine (EPI, beta- and alpha2-agonist) on in situ lipolytic response of s.c. adipose tissue were investigated in vivo, using a microdialysis method to measure glycerol release, in 12 adult nonlactating and ovariectomized, underfed Lacaune ewes. All the adrenergic compounds were perfused for 120 min at 10(-6), 10(-5), and 10(-4) M. They had no lipolytic effect at 10(-6) M. Isoproterenol and EPI at 10(-5) and 10(-4) M enhanced, in the same way, maximal response and area under the concentration curve (AUC) of dialysate glycerol, thus suggesting that involvement of alpha2-adrenoceptors in the control of in situ lipolysis is of minor importance in underfed ewes. Terbutaline had only a slight lipolytic effect at 10(-5) M. This low effect could be due to a lower affinity of TER than of ISO for the beta2-adrenoceptors. The beta3-agonist, CL, had no lipolytic effect whatever the concentration perfused. Further studies are needed to prove the putative presence of beta3-adrenoceptors and their possible role in the ovine adipose tissue.
Ferlay
A
A
Adipose Tissue and Milk Lipids Team, Herbivore Research Unit, INRA, Theix, Champanelle, France.
Charret
C
C
Galitzky
J
J
Berlan
M
M
Chilliard
Y
Y
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose; D018592:Cross-Over Studies; D004837:Epinephrine / Q000494:pharmacology*; D005110:Extracellular Space / Q000187:drug effects / Q000502:physiology; D005227:Fatty Acids / Q000097:blood; D005260:Female; D005508:Food Deprivation / Q000502:physiology; D005990:Glycerol / Q000097:blood; D007545:Isoproterenol / Q000494:pharmacology; D019344:Lactic Acid / Q000097:blood; D008066:Lipolysis / Q000187:drug effects* / Q000502:physiology; D017551:Microdialysis / Q000662:veterinary; D011943:Receptors, Adrenergic, beta / Q000145:classification / Q000502:physiology*; D012756:Sheep / Q000378:metabolism*; D013726:Terbutaline / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D001786:Blood Glucose; D005227:Fatty Acids; D011943:Receptors, Adrenergic, beta; D019344:Lactic Acid; D007545:Isoproterenol; D013726:Terbutaline; D005990:Glycerol; D004837:Epinephrine