Effects of estrogen on free fatty acid metabolism in humans.
To determine whether estrogen directly affects effective adipose lipolysis, palmitate rate of appearances ([14C]palmitate) was measured in 15 postmenopausal women. Each volunteer was studied after > or = 2 mo of estrogen treatment and again after > or = 2 mo of estrogen deficiency. Plasma hormone concentrations were controlled and identical on the 2 study days with use of the pancreatic clamp technique, and the lipolytic response to epinephrine and epinephrine + phentolamine was assessed. Results showed that overall palmitate flux was greater (10-20%, P < 0.05) during the estrogen-deficient than during the estrogen-replete study. Adrenergic stimulation of lipolysis was not specifically influenced by estrogen treatment, and control of plasma hormone concentrations did not eliminate the difference in palmitate flux between the estrogen-deficient and estrogen-replete study days. We conclude that estrogen deficiency is associated with increased plasma free fatty acid availability and that estrogen likely has direct, albeit small, effects on adipose tissue lipolysis.
Jensen
M D
MD
Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905.
Martin
M L
ML
Cryer
P E
PE
Roust
L R
LR
D001786:Blood Glucose / Q000032:analysis; D002153:Calorimetry, Indirect; D002319:Cardiovascular System / Q000187:drug effects; D002395:Catecholamines / Q000097:blood; D004967:Estrogens / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005260:Female; D006728:Hormones / Q000097:blood; D006801:Humans; D008875:Middle Aged; D009994:Osmolar Concentration; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000097:blood
D001786:Blood Glucose; D002395:Catecholamines; D004967:Estrogens; D005230:Fatty Acids, Nonesterified; D006728:Hormones; D010169:Palmitic Acids; D019308:Palmitic Acid