Survey of Carnitine Content of Human Semen Using a Semiquantitative Auxanographic Method: Decreased Semen Total Carnitine Concentration in Patients with Azoospermia or Severe Oligozoospermia

A microbiological method, using the carnitine‐requiring yeast, Torulopsis bovina ATCC 26014, was developed to identify samples of human semen which contained low levels (< 250 μM) of total carnitine. Of 399 semen samples from a male infertility clinic which were tested, 30 (7.5%) were low in carnitine. Of these, 14 were azoospermic and 16 were severely oligozoospermic. Some azoospermic samples (19 = 58%) and severely oligozoospermic samples (51 = 79%) did not give evidence of low carnitine concentrations. These results indicate that decreased total carnitine concentration in semen occurs in certain classes of azoospermic and severely oligozoospermic patients.