Ascorbic
acid and reproduction in fish: endocrine regulation and gamete quality
K. Dabrowski, A. Ciereszko-2001
Aquaculture
Research, 32(8) : 623-638
Abstract:
High ascorbic acid concentrations have been
associated with gonad and brain tissues in teleost fishes. Although a direct
dietary effect on gamete quality has been given some attention recently, the
mechanism of action of ascorbate along the cascade of reproductive events in
the hypothalamus, pituitary and gonads has not been defined. Data relating
to gamete production and quality, as well as a possible protective role for
ascorbate against cumulative genetic defects during gametogenesis and
congenital malformation during gestation (embryonic development) is
reviewed. It is suggested that the gonad growth in response to gonadotropin
stimulation involves direct interaction between catecholamines and steroid
hormones and their receptor sites. This interaction acts as a regulatory
mechanism of ascorbate absorption, transfer and metabolism (degradation
and/or renewal) in the reproductive system. We conclude that ascorbic acid
is a leading nutrient in reproductive tissue functions and further research
is needed on: (1) its antioxidant effect on gametes' (sperm and ova)
capacity to prevent DNA damage occurring prior to (endogenous) and after
spawning (environmental insults); (2) its dietary requirement to optimize
survival and physiological recovery in multiple spawners; (3) the
integration mechanism of ascorbic acid action as part of the overall
endocrine regulation of neurohormonal–hormonal pathway in fish
reproduction; and (4) the possible role for ascorbate in regulating fish
maturation and/or infertility in the presence of enhanced UV-radiation or
conditions of intensive aquaculture (hypoxia, oxygen supersaturation,
dietary pro–, and antioxidants).
(School of Natural Resources, The Ohio State
University, 2021 Coffey Road, Columbus OH 43210-1085, USA)