Susana Isabel Ferreira da Silva de Sá ESTROGÉNIOS E ...

Table 1. Serum estradiol and progesterone levels, uterine weight and lordosis intensity in rats belonging to the different groups analyzed in
Experiments 1 and 2
weight was similar to that of estradiol-treated rats and,
accordingly, was significantly higher than in oil-treated
rats. Rats treated with DPN had uterine weights similar to
those of rats treated with oil or progesterone alone. Progesterone
administration had no statistically significant effect
(P0.05) on uterine weight compared to oil-treated
rats.
Numerical density of synapses
Estradiol (pg/ml) Progesterone (ng/ml) Uterine weight (g) Lordosis intensity
O group 33.17 (3.14) 4.02 (0.22) 0.25 (0.03) 0
P group 33.70 (0.71) 14.52 (0.84) 0.24 (0.02) 0
EBP group 59.55 (4.49)* 13.48 (0.59) 0.91 (0.09) ## 2.5 (0.22)
EBRU group 64.76 (9.14)** 4.69 (0.14) 1.10 (0.16) ## 0
EB group 63.47 (5.87)* 5.82 (0.66) 0.89 (0.07) ## 0
2 EB group 110.61 (7.09) xxx 5.56 (0.64) 0.79 (0.05) # 0
PPT group 34.17 (4.09) 3.63 (0.54) 0.81 (0.08) ## 0
DPN group 33.23 (3.90) 4.40 (0.60) 0.25 (0.21) 0
Values are expressed as means (SEM). * P0.05; ** P0.005, compared with groups that were not injected with estradiol; xxx P0.0005 compared
with all other groups; P0.0005 compared with groups that were not injected with progesterone; # P0.005, ## P0.0005 compared with O-, P- and
DPN-treated groups.
In Experiment 1 (Fig. 2), in which O, P, EB, EBP and
EBRU groups were studied, we found no significant influence
of treatment in the N V of spine (F 4,252.85;
P0.05) and dendritic (F 4,251.75; P0.17) synapses. In
contrast, in Experiment 2 (Fig. 3), in which O, EB, 2 EB,
PPT and DPN groups were analyzed, ANOVA revealed a
significant effect of treatment on the N V of both types of
synapses (F 4,2519.90; P0.0001 for spine and F 4,25
7.63; P0.0004 for dendritic synapses). With respect to
spine synapses, the density was significantly higher in 2
EB- and PPT-treated rats than in the remaining groups. In
dendritic synapses, this difference was only apparent for
the PTT-treated group and no significant difference was
found between 2 EB-treated rats and the remaining
groups.
Fig. 2. Graphic representation of the N V of spine (white columns) and
dendritic (black columns) synapses in the VMNvl of rats studied in
Experiment 1. The number of animals per group was six. On average,
200 synapses were counted per animal. Columns represent means
and vertical bars 1 SD.
S. I. Sá et al. / Neuroscience 162 (2009) 307–316 311
Neuronal numerical density
ANOVA revealed a significant influence of treatment in the
N V of VMNvl neurons in Experiment 1 (F 4,255.70; P
0.005) as well as in Experiment 2 (F 4,257.46; P0.0005).
In Experiment 1 (Fig. 4), rats injected with estradiol (EB,
EBP and EBRU groups) had significantly fewer neurons
per unit volume of the VMNvl than rats injected with oil
or progesterone (O and P groups). In Experiment 2 (Fig.
4), rats treated with estradiol (EB and 2 EB groups) and
rats receiving ER agonists (PPT and DPN groups) had
significantly lower neuronal numerical densities than oiltreated
rats. No significant differences were detected
among EB, 2 EB, PPT and DPN groups.
Total number of synapses per neuron
The variations in synapse numbers induced by the administration
of hormones, and receptor agonists and antagonists
are shown in Figs. 5 and 6 and summarized in the
diagram shown in Fig. 7. Treatments used in Experiment 1
significantly influenced the total number of spine (F 4,259.57;
P0.0001) and dendritic (F 4,257.73; P0.001) synapses
established by each VMNvl neuron (Fig. 5). The number of
Fig. 3. Graphic representation of the N V of spine (white columns) and
dendritic (black columns) synapses in the VMNvl of rats studied in
Experiment 2. The number of animals per group was six. On average,
200 synapses were counted per animal. Columns represent means
and vertical bars 1 SD. Tukey’s post hoc tests: * P0.05, ** P0.0005
compared with O-treated group; P0.005, P0.0005 compared
with EB-treated group; # P0.005 compared with DPN-treated group.
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