Total organic osmolyte content (L-carnitine + L-glutamate + myo-inositol + D-sorbitol) expressed per unit glucose-6-phosphate dehydrogenase (G6PDH) activity in spermatozoa treated by control Protocol C (C), A (A) and B (B), each partitioned into the percentages occupied by sorbitol (□), inositol (□), glutamate (□), carnitine (□). §, Proportion of carnitine significantly lower than that in Protocol C.