Vie CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. II

Harrison § Heald (2) found poly-glutamic acid in those portions
of the oviduct where the spermatozoa are stored and reported that
the extracted as well as synthetic poly-GA prolonged the viability
of cock spermatozoa in vitro at 40°C. It occurred to us that per-
haps this was the physiological motility inhibitor sought after, at
least in the hen. Unfortunately, it had no effect one way or the
other on motility or on metabolic rate (table 1 § text fig. 1).

The effect of temperature on the rate of acid production from
glucolysis and on motility is shown in text fig. 1. Between 19° and
23°C, a difference of only 4°, APR increased by a factor of 3;
between 23° to 28°C APR increased 2.5 times; between 28° and 41°C
there was only a slight increase in APR. When tne temperature was
raised above 40°C the spermatozoa became immotile, but there was no
reduction in APR. Rate of oxygen uptake also did not diminish at

this temperature (6). Hence, motility of cock spermatozoa can be
uncoupled by temperature from its source of metanliC energy, without
affecting the metabolic rate.

100

  
 
 
 
 
 
 
 
 
 
 
  

poly GA
90 motility %

Fig. 1. Total acid
80 : production as a

| function of tempe-
motility | rature under
anaerobic condi-
tions pH = 7,2,

70

60

50

40

/4 equivalents NaOH

30

20

0 40 80 120
minutes

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