Download presence of ascorbic acid in cirripede semen

NOTES
AND
COMMENT
PRESENCEOF ASCORBIC&ID
During the course of some biochemical
work on cirripede semen the presence o$
considerable quantities of a reducing sub4
stance not carbohydrate in nature was ob;
served. 2: 6 dichlorophenolindophenol
and
osmic acid were strongly reduced and the
prescncc of ascorbic acid was, thereford
suspected. The 2: 4 dinitrophcnylhydrazina
method of Rot ( 1954) indicated the pres&
cncc of 21 pg/ml ascorbic acid of seminal
plasma and 12 pg/g of centrifuged sperma+
tozoa of Bdanus balmus. The prcscnce of
reducing substances, other than carbohyb
drates, in semen is well known ( Mann 1954)‘.
Mann and Lconc (1953) have shown tha;b
in some animals, especially the boar, th&
reducing substance is largely ergothioneiny,
although in others ascorbic acid may largely
be responsible. Ergothioneine was shown to
be absent in the semen of cirripedes. Reducing substances in mammalian semen are
produced by the seminal vesicles and it is of
considerable interest to find ascorbic acid iD
the semen of an invertebrate, of which this iis
the first record, and in which the so-called
seminal vesicles are supposedly only storagb
organs and are not functionally comparablp
with those of a mammal.
The function of reducing substances ih
semen is not entirely understood. According to Phillips, et al. ( 1940)) high fertiliyy
bulls produce semen containing more ascorbic acid than low fertility bulls and the
parental administration of ascorbic acid eohanccs fertility.
Mann ( 1954) considcrdd
that the importance of ergothioncine might
lie in its protective action on spermatozda
exercised through its reducing -SH groutis.
Rrachet ( 1944) ,and MacLeod ( 1951) have
indicated the importance of reducing -SB
groups for semen motility; cysteine and gltltothione protect spermatozoa in vitro fro!n
the inhibiting action of -SH binding agents.
Mann and Leone ( 1953) have further sho+n
that ergothioneine is capable of countera@ing the paralyzing action of many reagerlts
which either combine with or oxidize - dH
groups.
IN CII~RIPEDE SEMEN
Ascorbic acid cannot, like ergothioneinc,
directly protect against -SH binding agents,
although it may afford protection against
oxidizing substances. It has, however, been
found that the seminal plasma of B. halanzcs
contains considcrablc quantities of cystine;
indeed it is by far the commonest amino
acid indicated by paper chromatography.
In addition to a possible direct protection
against oxidizing substances, ascorbic acid
may then take part in a system maintaining
the presence of -SH groups which in turn
protect -SH enzymes against the presence of
heavy metals and other thiol reactive agents.
It is also of interest to recall that ascorbic
acid in concentrations of 14 lug/L has been
shown by Collier, Ray, and Wilson ( 1956)
to induce copulatory activity in barnacles.
Further work on the origin and function
of ascorbic acid in a number of common cirripcdes and other crustaceans is in progress.
H.
BARNES
AND
D. M. FINLAYSOK
The Marine Station,
Millport, Scotland
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