148
H.FÊ. Lin ef: al.
The present studies indicate that blocking the GRIF activity of
_
dopamine by treatment with the receptor antagonist PIM potentiates the
GtH—releasing activity of LHRH—A in common carp, bream, silver carp, and œ
loach.
In
each
species the combined treatment of PIM and LHRH—A, at
-
appropriate dosages, is highly effective in inducing ovulation°
Preliminary
studies
also
indicate
that
this
procedure will also be useful for inducing
ovulation in mud
carp
(Cirrhinus molitorella), grass carp (Ctenopharyngodon
idellus) and big head, (Aristichthys nobilis; unpublished results)°
On the
basis
of
literature
(see Introduction) and present results it is apparent
that
the
combination of PIM plus LHRH—A is generally effective for inducing
ovulation in cypriniform and other teleosts°
Notably, the combination of treatment with RES and LHRH—A is also
highly effective in stimulating GtH secretion and inducing ovulation_in at
least
common
carp and loach.
This
suggests that any drug which blocks
dopamine synthesis will also be effective in potentiating the action of
LHRH—A.
This
is
important for applied work in this field because such drugs
are
generally more readily available than the various dopamine receptor
antagonists°
The
results with
the bream and
silver
carp
indicate
that
treatment
with PIM plus LHRH—A induces ovulation within a relatively short
and predicable time following injection°
Such predicability of the response
time
is
important for applied purposes.
Finally, the fertility and survival
of
eggs
taken from female
carps
induced to ovulate With PIM plus LHRH—A are
the
same
as
for eggs
taken from spontaneously ovulated females (unpublished
results), indicating that this technique is indeed practical for inducing
ovulation of
farmed fishes.
ACKNOWLEDGEMENTS
This work was
supported by grant 3—P—83—1101 from the International
Development Research Centre of Canada to H.,—Ru Lin and R«E. Peter°
REFERENCES
BILLARD, R., ALAGARSWAMI, K.,, PETER, R.E., BRETON, B…, 1983°
Potentialisation par le pimozide des effets du LH—RH—A sur la secretion
gonadotrope hypophysaire l‘ovulation et la spermiation chez la carpe
commune
(Cyprinus carpio)° C.R.Acad°SciuParis, Serie III,
181—184'
BILLARD, R., REINAUD, P., HOLLEBECQ, MoG., BRETON,
1984° Advancement
and
synchronization of spawning in Salmo gairdneri and S. trutta
following administration of LRH—A
Eim3EÎËEÎ
Aquaculture
57—66.
,
BURNSTOCK, G., 1958. Saline for fresh—water fish. J,Physiol., 141, 35—45—
CHANG, J-P-, PETER, R.E., 1983a. Effects of pimozide and des—Glylo[D—alaô]
luteinizing hormone releasing hormone ethylamide on serum gonadotropin
concentrations, germinal vesicle migration and ovulation in female
goldfish, Carassius auratus. Gen.Comp.Endocrinola, 52, 30—37CHANG» J-P=: PETER, R-E-, 1983b° Effects of dopamine on gonadotropin release
in female goldfish, Carassius auratus. Neuroendocrinology, 36, 351—357—
H.FÊ. Lin ef: al.
The present studies indicate that blocking the GRIF activity of
_
dopamine by treatment with the receptor antagonist PIM potentiates the
GtH—releasing activity of LHRH—A in common carp, bream, silver carp, and œ
loach.
In
each
species the combined treatment of PIM and LHRH—A, at
-
appropriate dosages, is highly effective in inducing ovulation°
Preliminary
studies
also
indicate
that
this
procedure will also be useful for inducing
ovulation in mud
carp
(Cirrhinus molitorella), grass carp (Ctenopharyngodon
idellus) and big head, (Aristichthys nobilis; unpublished results)°
On the
basis
of
literature
(see Introduction) and present results it is apparent
that
the
combination of PIM plus LHRH—A is generally effective for inducing
ovulation in cypriniform and other teleosts°
Notably, the combination of treatment with RES and LHRH—A is also
highly effective in stimulating GtH secretion and inducing ovulation_in at
least
common
carp and loach.
This
suggests that any drug which blocks
dopamine synthesis will also be effective in potentiating the action of
LHRH—A.
This
is
important for applied work in this field because such drugs
are
generally more readily available than the various dopamine receptor
antagonists°
The
results with
the bream and
silver
carp
indicate
that
treatment
with PIM plus LHRH—A induces ovulation within a relatively short
and predicable time following injection°
Such predicability of the response
time
is
important for applied purposes.
Finally, the fertility and survival
of
eggs
taken from female
carps
induced to ovulate With PIM plus LHRH—A are
the
same
as
for eggs
taken from spontaneously ovulated females (unpublished
results), indicating that this technique is indeed practical for inducing
ovulation of
farmed fishes.
ACKNOWLEDGEMENTS
This work was
supported by grant 3—P—83—1101 from the International
Development Research Centre of Canada to H.,—Ru Lin and R«E. Peter°
REFERENCES
BILLARD, R., ALAGARSWAMI, K.,, PETER, R.E., BRETON, B…, 1983°
Potentialisation par le pimozide des effets du LH—RH—A sur la secretion
gonadotrope hypophysaire l‘ovulation et la spermiation chez la carpe
commune
(Cyprinus carpio)° C.R.Acad°SciuParis, Serie III,
181—184'
BILLARD, R., REINAUD, P., HOLLEBECQ, MoG., BRETON,
1984° Advancement
and
synchronization of spawning in Salmo gairdneri and S. trutta
following administration of LRH—A
Eim3EÎËEÎ
Aquaculture
57—66.
,
BURNSTOCK, G., 1958. Saline for fresh—water fish. J,Physiol., 141, 35—45—
CHANG, J-P-, PETER, R.E., 1983a. Effects of pimozide and des—Glylo[D—alaô]
luteinizing hormone releasing hormone ethylamide on serum gonadotropin
concentrations, germinal vesicle migration and ovulation in female
goldfish, Carassius auratus. Gen.Comp.Endocrinola, 52, 30—37CHANG» J-P=: PETER, R-E-, 1983b° Effects of dopamine on gonadotropin release
in female goldfish, Carassius auratus. Neuroendocrinology, 36, 351—357—