Transport of carnitine by the epididymis of the cynomolgus macaque (Macaca fascicularis).

Unravelled tubules from the monkey caput and cauda epididymidis were perfused through the lumen in vitro during immersion in an organ bath kept at scrotal temperature and containing [3H]carnitine and [14C]inulin. The specific transport of carnitine from the bath to the lumen was constant for 4 h and reached a steady-state value of about 90 pmol/30 min per cm perfused length in the cauda and about 30 pmol/30 min/cm in the caput. These regional variations in carnitine transport differ from those found in the rat epididymis but may be relevant to human epididymal physiology.