Vle CONG. INTERN. REPROD. ANIM. INSEM. ARTIF.,, PARIS, 1968, VOL. Il

DISCUSSION AND CONCLUSION

From the above mentioned experiments it is evident,
that transaminases are present in boar spermatozoa

but not in boar seminal plasma.After treatment of the
spermatozoa with an Elvehjem Potter homogenizer, trans-
aminase activity is obvious, but this is bound to the
residues of the spermatozoa and it is not present in
the watery solution.

The fact, that after incubation of homogenized
spermatozoa with water phenylpyruvic acid was not
present, is well understandable, as spermatozoa do
not contain free phenylalanine. The formation of
a-keto-leu and of a-keto-B under these circumstances
is comprehensible, as leu does occur free in sperma-
tozoa and "B" can be liberated rather easily.The ob-
servation, that valine cannot be transaminated, is in
agreement with the fact, that a-keto-val cannot be
detected in boar seminal plasma.

Inexplicable remains the fact, that incubation of
homogenized "normal" spermatozoa with "normal" seminal
plasma results in formation of only a=-keto-leu and
a=keto-B as after incubation of "bad" spermatozoa
with "bad" seminal plasma also phenylpyruvic acid
is present. It may be, that in both cases phenylpyruvic
acid first is formed, but that in normal plasma it is
converted immediately and in "bad" plasma is notj;it
may be also, that the transamination of small amounts
of phenylalanine is inhibited. These questions are
still under investigation, the same as the isolation
of the enzyme.

The concentration of a-keto-leu is very low in
normal boar seminal plasma and as already mentioned,
a-keto-B is only present in a few cases. The presence
of phenylpyruvic acid and ef relatively large amounts
of w-keto-leu and a-keto-B in semen, may be an indi-
cation that the spermatozoa are affected and in such
a way, that transaminase activity can occur.

Whether the presence of phenylpyruvic acid itself
influences the fertility rate or that the damage
of the spermatozoa is more important in this respect,
has to be investigated.

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