Short-Term 17-β-Estradiol Administration Does Not Affect Metabolism in Young Males
Journal Articles
Overview
Research
Identity
Additional Document Info
View All
Overview
abstract
We have previously demonstrated that females oxidize more lipid and less protein and carbohydrate during endurance exercise [21]. Several studies in male rats have demonstrated similar metabolic changes after 4 d of 17-beta-estradiol (E2) administration. Our purpose was to study the effects of E2 administration upon substrate metabolism during 90min of cycle ergometry at 60% VO2peak in 11 healthy, young males. E2 was administered in a single-blind, cross-over, randomized fashion for 11 d (100 microg.d(-1) x 3.5d --> 200 microg.d(-1) x 3.5 d --> 300 microg.d(-1) x 4.0 d). Respiratory exchange ratio (RER), VO2, Ve, HR, lactate, and glucose were measured every 30 min during exercise and E2, testosterone TEST, glycerol and triglycerides were measured prior to exercise T = 0 min. Muscle biopsies were taken from the vastus lateralis before and after exercise for glycogen determination. Estradiol treatment resulted in lower plasma TEST (20.8-->7.8 nmol.L(-1), P<0.0001) and higher plasma E2 (168.1 327.3 pmol.L(-1), P < 0.002). Therewere no effects of E2 treatment upon any of the other measured variables including muscle glycogen: (E2 - PRE = 529.3 --> POST = 237.9; PL-PRE = 582.2 --> POST = 262.4 mmol.kg(-1) [dm]). We concluded that short-term E2 treatment increased plasma E2 to female follicular levels in males but had no effect upon lipid or carbohydrate metabolism.
