Effect of somatotropin on adipose tissue net glucose-stimulated lipogenesis in young goats.
Net glucose-stimulated lipogenesis (NGSL: the rate of lipogenesis in the presence of glucose minus the rate of lipogenesis in the absence of glucose) in omental adipose tissue explants from young castrated male goats was evaluated in control animals (n = 3; placebo-treated) and in animals treated with the sustained release of recombinant bovine somatotropin (n = 4; bST; 100 mg at 7-day intervals in a 147 days lasting experiment). The rate of fatty acid synthesis was determined in acute incubations in both freshly prepared and chronically cultured explants. Adipose explants remained metabolically active and retained their ability to respond to hormones when maintained in a tissue culture medium. NGSL in explants cultured for 24 h in the presence of insulin alone or bST alone, was non-significantly increased (more in the controls) and decreased (more in bST-treated animals), respectively. However, cortisol alone decreased (P<0.05) NGSL in explants from both control and bST-treated animals. In tissues from bST-treated animals, cortisol acted synergistically with insulin to produce a higher rate of NGSL than that observed in cultures with insulin alone. bST inhibited insulin plus cortisol-stimulated lipogenesis significantly (P<0.05) in explants from bST-treated animals but non-significantly in control animals. The rates of NGSL were decreased (P<0.05) by catecholamines in explants from both control and bST-treated animals. Norepinephrine (NE) and isoprenaline (ISO) were equally effective in the controls, whereas isoprenaline was more effective than norepinephrine in bST-treated animals.
Skarda
J
J
Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Prague. skarda@iapg.cas.cz
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D046508:Culture Techniques; D005947:Glucose / Q000494:pharmacology*; D006041:Goats; D013006:Growth Hormone / Q000494:pharmacology*; D008055:Lipids / Q000096:biosynthesis*; D008297:Male
D008055:Lipids; D013006:Growth Hormone; D005947:Glucose