ABSTRACT
This study investigated the effect of high-intensity interval exercise on total and individual amino acid concentrations in red blood cells (RBCs) and plasma. Seven males (31 ± 13 yr) provided venous blood samples at rest, immediately and 15 min and 30 min following an 8-min high-intensity exercise bout. The exercise bout was 16 × 15 s cycle efforts at 0.4N/kg of body mass and 90 rpm, interspersed with 15 s passive recovery. Total and individual amino acid concentrations of RBC and plasma and blood cell parameters were analysed. No significant differences for total amino acid concentrations between RBC and plasma were found. Individual amino acid analyses showed significant interaction effects for alanine and α-aminoadipic acid (P < 0.05), with plasma alanine significantly increased from baseline across the recovery period (P < 0.001). Blood fraction (group) effects showed greater concentrations of glycine, serine, asparagine, aspartic acid, glutamic acid, α-aminoadipic acid and ornithine in RBC, while greater concentrations of alanine, α-aminobutyric acid, valine, leucine, isoleucine, threonine, proline, phenylalanine, glutamine, tryptophan and cystine were found in plasma (P < 0.05). Comparable levels of histidine, lysine and tyrosine were observed between blood fractions. Significant differences in the variation of total amino acids in RBC were reported with higher variance at rest compared to following exercise (P = 0.01). Haemoglobin, pack cell volume and white blood cell count significantly increased immediately following exercise (P < 0.05) but returned to baseline after 15 min recovery. These results support the notion of individualised amino acid transportation roles for RBC and plasma during exercise.
Subject(s)
Amino Acids , Erythrocytes , Male , Humans , Plasma , Alanine , Glutamic AcidABSTRACT
Tamoxifen is a non-steroidal selective oestrogen receptor modulator commonly used in the treatment of breast cancer. It is associated with the development of fatty liver and steatohepatitis however drug-induced liver injury is rare. We report a woman in her 50s who developed malaise with an acute moderate aminotransferase elevation without jaundice 6 months after starting tamoxifen. She was not commenced on any other recent drugs and extensive investigation including infective and autoimmune liver screen, cross-sectional imaging and FibroScan were unremarkable. Liver biopsy revealed moderate lobular hepatitis with hepatocyte drop-out. Tamoxifen was ceased and the liver enzymes showed resolution over the following 3 months and improvement of her symptoms.