CARNITINE MEASUREMENTS IN LIVER, MUSCLE-TISSUE, AND BLOOD IN NORMAL SUBJECTS

We determined carnitine concentrations in blood and in liver and abdom inal muscle biopsy specimens in 13 men and 16 women undergoing electiv e surgery (mostly gall-bladder removal). The data suggest that the car nitine pools of plasma and erythrocytes are different. The erythrocyte s show a higher acylcarnitine concentration than does plasma (P <0.001 ). Several reference bases for values in tissues have been used-dry we ight, noncollagen protein (NCP), and DNA-because these may be differen tly influenced by disease. In liver specimens, the quotient NCP (g)/DN A (g) was significantly higher in men, 54.4 +/- 6.3 (mean +/- SD), tha n in women, 47.7 +/- 7.0 (P <0.01). Liver total carnitine content in r elation to DNA was significantly higher in men than in women: 0.29 +/- 0.06 vs 0.22 +/- 0.08 mmol/g DNA (P <0.01). Free carnitine content wa s significantly higher in men than in women independently of the refer ence base, e.g., 3.7 +/- 1.0 mumol/g NCP for men vs 2.9 +/- 1.0 for wo men (P <0.05). No difference was found between the sexes in the abdomi nal muscle carnitine content, 20.6 +/- 6.7 mumol/g NCP for men vs 17.9 +/- 5.0 for women. Our study establishes control ranges, thereby prov iding an important basis for studies of patients with abnormal carniti ne metabolism.