Examining the effects of 4 weeks of Citrulline alone or in combination with glutathione on the arterial function of postmenopausal women.
L-Citrulline is a non-protein amino acid and an efficient precursor of L-arginine, the substrate for endothelial nitric oxide synthesis. Glutathione is a tripeptide with antioxidant effects. Postmenopausal women will ingest 6g/d of L-Citrulline or 2g of L-Citrulline plus 200mg/d of glutathione or placebo (maltodextrin) for 4 weeks with vascular function testing prior to and after the intervention.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
39
Four weeks of oral L-Citrulline (2 grams/day) supplementation. Supplementation will be ingested daily, half of the doses in the morning and half at night.
Four weeks of oral L-Citrulline (6 grams/day) supplementation. Supplementation will be ingested daily, half of the doses in the morning and half at night.
Four weeks of oral placebo (6 grams/day maltodextrin) supplementation. Supplementation will be ingested daily, half of the doses in the morning and half at night.
TTU Kinesiology and Sport Management Building
Lubbock, Texas, United States
Change in endothelial function
Endothelial function will be measured before and after the intervention using brachial artery flow mediated dilation at rest, blood flow measured in the brachial artery during handgrip exercise, and blood flow in the common femoral artery during passive leg movement. All measurements performed using doppler ultrasound.
Time frame: 4 weeks
Change in arterial stiffness
Arterial stiffness will be assessed through measurement of pulse-wave velocity of the carotid-femoral, carotid radial, carotid-ankle and femoral ankle arterial segments before and after the 4 week interventions.
Time frame: 4 weeks
Blood pressure control during the cold pressor test
Blood pressure will be measured during the cold pressor test before and after the 4 weeks.
Time frame: 4 weeks
L-Arginine bioavailability
Plasma levels of arginine will be measured before and after the 4 week intervention.
Time frame: 4 weeks
cardiovascular hemodynamics using pulse wave analysis during the cold pressor test
arterial tonometry will be measured during the cold pressor test before and after the 4 week intervention.
Time frame: 4 weeks
body composition
We will determine whether L-citrulline + glutathione changes body composition more than L-citrulline or placebo.
Time frame: 4 weeks
Muscle Strength
Leg Extension strength will be measured before and after the 4 weeks.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Four weeks of Glutathione (200mg/day) supplementation. Supplementation will be ingested daily, half of the doses in the morning and half at night.
Time frame: 4 weeks
L-Citrulline levels
Plasma levels of L-Citrulline will be measured before and after the 4 weeks.
Time frame: 4 weeks
Glutathione peroxidase levels
Blood levels of glutathione peroxidase will be measured before and after the 4 weeks
Time frame: 4 weeks
Malondialdehyde
blood levels of malondialdehyde will be measured before and after the 4 weeks
Time frame: 4 weeks
L-Ornithine levels
plasma levels of L-ornithine will be measured before and after the 4 weeks
Time frame: 4 weeks