LH plasma levels are shown in Table 2. LH plasma levels were nondetectable (< 0.15 ng/ml, 0.015 ng/RIA tube) in all specimens sampled in spring or in July. In autumn, however, plasma LH levels reached the detection limit in most sham-operated males, being higher in November than in September (p < 0.001, experiment 2). Plasma LH levels were nondetectable in all castrated (significantly below the value in sham-operated fish; p < 0.01, experiment 1; p < 0.01, experiment 2, September; and p < 0.001 experiment 2, November) or llKA-treated males. Many T-treated males displayed detectable plasma levels of LH in September and November; these were, however, not significantly different from those for the castrated controls.
The pituitary content of FSH in experiments 1 and 2 is shown in Figures 3 and 4, respectively. In spring, the FSH content was significantly higher in mature than in immature males (experiment 2, p < 0.001). Pituitary FSH levels in sham-operated fish increased during the summer-autumn relative to those found in spring (both experiments). In experiment 2, the levels were highest in November (p < 0.001, compared to both July and September). The pituitary FSH content in castrated fish was lower than in sham-operated fish (p < 0.001, experiment Up < 0.05, experiment 2, July; p < 0.001, experiment 2, September and November), but the differences were less marked than for LH. Compared to the value in the castrated controls, the pituitary FSH content in T-treated fish was lower in July (p < 0.001) and higher in November (p < 0.001). In September, the pituitary FSH content was not significantly different between T-treated and castrated control fish. The FSH content in 11KA-treated fish was higher than in castrated controls in autumn (p < 0.001, in both September and November). In July, pituitary FSH content was higher in 11KA-treated than in T-treated males (p < 0.01). buy ortho tri-cyclen online
FIG. 3. Effects of castration on pituitary FSH content in male salmon parr in experiment 1. Means ± SEM for initial controls and sham-operated and castrated fish are given. In one group, SEM is too small to show. Number of fish is indicated on top of bars. For statistics, see Results.
FIG. 4. Effects of castration and treatment of castrated fish with T or 11 KA on pituitary FSH content in male salmon parr in experiment 2. Means ± SEM for mature and immature initial controls, sham-operated fish, castrated fish, and castrated fish treated with T or 11 KA are given. In some groups, means and SEM are too small to show. Number of fish is indicated on top of bars. For statistics, see Results.