N. Hiramatsu et al., TRANSITION OF SERUM VITELLOGENIN CYCLE IN SAKHALIN TAIMEN (HUCHO-PERRYI), Comparative biochemistry and physiology. C. Comparative pharmacologyand toxicology, 118(2), 1997, pp. 149-157
A specific and sensitive enzyme linked immunosorbent assay (ELISA) and
a single radial immunodiffusion (SRID) were developed for measurement
of serum vitellogenin (Vg) levels in Sakhalin taimen (Hucho perryi).
Regarding specificity for serum Vg, an antiserum raised against lipovi
tellin of taimen (a-Lv) was adequate for both assays. ELISA and SRID c
ould detect Vg in serum at concentrations as low as 10 ng/ml and 25 mu
g/ml, respectively. In estrogen administration experiments, the level
of serum Vg began clearly increasing within 12 to 24 hr after injecti
on of immature females with estradiol-17 beta (E-2) The appearance and
levels of Vg in males treated with E-2 were delayed and smaller, resp
ectively, than for females. Vg levels varied throughout natural vitell
ogenesis from 0-4 mu g/ml (3 years old) to approximately 30 mg/ml (5-6
years old). We observed an early transitory peak of serum Vg levels (
primary reaction) at the time of early vitellogenesis and chronic high
Vg levels (for 6-7 months) in winter period before ovulation. Changes
of serum E-2 levels were correlated with Vg levels. However, E-2 leve
ls decreased a month earlier than Vg levels near ovulation. It appears
that the duration of vitellogenesis in taimen is considerably longer
than that in other salmonids, lasting more than 2 years. (C) 1997 Else
vier Science Inc.