Effect of 17 beta-estradiol on different parts of central nervous system of female Singi fish (Heteropneustes fossilis Bloch) in relation to reproductive stages.
Effects of different doses of 17 beta-estradiol (1, 2 and 4 micrograms/g, 3 consecutive days injections) on the protein, RNA and DNA contents of cerebrum (CB), cerebellum (CE), midbrain (MB), medulla oblongata (MO) and spinal cord (SC) of female non-vitellogenic (NV) and vitellogenic (V) Singi fish (Heteropneustes fossilis Bloch) were investigated. The amounts of these macromolecules in all these substructures of the central nervous system were enhanced on the 4th and/or 7th day in NV fish by estradiol depending on the dose. The higher dose(s) caused more marked effect. The dose of 1 microgram/g was ineffective in case of protein and mostly in case of DNA. There was no enhancement of protein content with any dose of estradiol on the 4th day in CE, MB, MO and SC, but in CB 4 micrograms of estradiol/g increased the protein content on this day. However, the increase was marked on the 7th day in all substructures. The enhancement of RNA content was elicited earlier (4th day) even with lower dose of 1 microgram/g in NV fish in most of the substructures, except MO. With exception of this substructure again, the DNA content of any part did not increase with the hormone on the 4th day with 1 microgram of estrogen/g. The changes in protein and nucleic acid contents of the different substructures of central nervous system in V fish with 17 beta-estradiol were mostly opposite to those in NV fish. Depending on the dose and time, protein and RNA contents of these parts decreased with estradiol in V fish. No change in DNA content, however, was found, except MO where this cellular constituent was surprisingly enhanced on the 4th and 7th day with all doses of estradiol used. The spinal cord of V fish did not show any change in RNA and DNA contents with the hormone. Thus a reproductive stage-specificity of estrogen action in fish brain is documented.
Ghosh
M
M
Department of Animal Physiology, Bose Institute, Calcutta, India.
Dasmahapatra
A K
AK
Medda
A K
AK
D000818:Animals; D002397:Catfishes / Q000502:physiology*; D002490:Central Nervous System / Q000187:drug effects* / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D009419:Nerve Tissue Proteins / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012098:Reproduction / Q000187:drug effects / Q000502:physiology; D014018:Tissue Distribution; D014819:Vitellogenins / Q000378:metabolism
D009419:Nerve Tissue Proteins; D014819:Vitellogenins; D004958:Estradiol; D012313:RNA; D004247:DNA