As seen in Figure 1, testicular seminiferous tubules epithelium
and spermatogonia of the underlying epithelial cells developed normally; there were chromatin clumps
along the nuclear membrane. Compared with the control
group, better spermatogonial development and more
uniform distribution of chromatin around the nuclear
membrane was observed in the group with a n-3/n-6
PUFA ratio of 1.52 (diet 4). Spermatocytes developed
better than control group (Figure 2). The bridge between
adjacent spermatocytes was visible and nucleoli were
prominent, mitochondria abundant, and lysosomes observed
in the cytoplasm in diets containing FO groups.
The structural integrity of mature sperm heads was
presented in every group (Figure 3), while sperm tail abnormalities
was more serious in the control group. Integral
acrosomal cap and tail outer dense fibers and
mitochondrial sheaths were observed in the testis in the
group consuming a n-3/n-6 PUFA ratio of 1.52 (diet 4).
Effects of the n-3/n-6 ratio on sperm tails histology are
shown in Figure 4. The central axoneme, nine dense peripheral
axonemal fibers, and the mitochondrial sheath in
cross-sections of the middle piece of the sperm tails in
the flaxseed oil supplemented groups were clearly visible
compared with the control group, and were evenly distributed
in the group consuming a n-3/n-6 PUFA ratio
of 1.52.
Effects of different ratios of N-3/N-6 PUFAs on
reproductive capacity
Effects of n-3/n-6 PUFA ratios on reproductive capacity
are shown in Table 6. The litter size in diet 1 group was
the lowest, and improved with increasing n-3/n-6 levels
(P < 0.05), while there was no significant difference between
the ratio 1.52 and 2.85 groups, indicating the importance
of an appropriate ratio of n-3/n-6 for normal
reproductive function in male rats. A similar result was
observed for birth weight, which was the lowest in diet 1
group and increased with the enhancing of the dietary
n-3/n-6 PUFA ratio (P < 0.05).
Effects of different ratios of N-3/N-6 PUFAs on the serum
hormone levels
The data for total circulating reproductive hormones are
shown in Table 7. The GnRH concentrations were significantly
higher in rats fed diet 4 compared with other
groups on day 30, and increased with the increasing of
the n-3/n-6 PUFA ratios on day 60 (P < 0.05). A similar
trend was observed for LH, FSH, and T concentrations.
The LH, FSH, and T concentrations in rats fed diet 4
were higher than other groups on days 30 and 60, and