Summary
Male Sprague-Dawley rats displayed significantly higher rates of triglyceride/fatty
acid (TG/FFA) substrate cycling in subcutaneous, perigenital, and mesenteric white
adipose tissue, compared to females.
To investigate possible regulation via androgens and estrogens, male rats were treated
with the androgen antagonist, cyproterone acetate (10 mg daily in subcutaneous injections),
or estradiol polyphosphate (0.3 mg intramuscularly, given as a single dose). Estradiol
treatment did not affect TG/FFA cycling. Treatment with cyproterone acetate significantly
decreasaed TG/FFA cycling in perigenital (epididymal) tissue. This effect could however
largely be ascribed to concomitant inhibition of food intake by cyproterone acetate.
The effects of cyproterone acetate on the two axes of TG/FFA cycling (lipolysis and
re-esterification) were further studied in vitro. Norepinephrine-stimulated glycerol
release from perigenital adipocytes was inhibited, whereas activities of esterification
enzymes (GPAT and PPH) was essentially unaffected.
We conclude that androgens seem to affect TG/FFA cycling indirectly via the lipolytic
axis.
Key words
Adipocytes - Cyproterone Acetate - Estradiol - Fatty Acids - Lipolysis - Rat - Triglycerides
