Table 2. Mean (± S.E.) blood plasma testosterone levels (ng/ml) and seminal plasma SOD (unit/g protein) in specimens collected from 4 low SOD-dogs before vitamin E supplementation and 5 control dogs.

Experimental groups (n)	Testosterone	SOD
Low SOD-dogs (4)	2.2 ± 0.2a)	10.7 ± 1.0 a)
Control dogs (5)	4.3 ± 0.3	35.7 ± 0.1

a) P<0.001, compared with the control dogs.