110 A
mone primed female rats and rarely in cycling females. Sections were then rinsed with PBS, mounted onto gelatin-
The present study was conducted in cycling and ovariec- coated slides, dehydrated in graded alcohol and cover-
tomized rats, in order to identify the spinal distribution of slipped with Eukitt. Five sections of each spinal segment
neurons responding to VCS and to verify whether the were randomly selected and examined under a light
estrous cycle modulates c-fos expression in lumbosacral microscope. Fos-immunoreactive neurons characterized by
spinal segments that receive sensory afferents from the the presence of a brown reaction product in their nuclei
vaginocervical area. were counted. The mean number of Fos-positive neurons
was calculated for each labeled area in each studied spinal segment. Comparison between areas within a segment,
2. Materials between segments within a group and between groups was
performed with analysis of variance ANOVA and pair- Adult virgin female Sprague–Dawley rats Centre Jaber
wise multiple comparison was performed with the Stu- Ben El Hayan FSS-Marrakech weighing 190–220 g were
dent–Newman–Keuls methods. Differences were consid- used in this study. Rats were housed in animal facilities
ered significant for P,0.05. under a 12:12 h Light Dark cycle light on at 08:00 h
To determine the estrous stage of each female, vaginal with free access to food and water.
smears were colored with 10 Giemsa and analyzed under VCS was performed in an experimental group of
a light microscope. We have observed that the smears females, lightly anaesthetized with an intra-peritoneal
performed using the balloon or by a conventional tech- injection of 25 mg of ketamine chlorhydrate kg bw,
nique gentle swap gived similar results. In the ex- ˆ
´ IMALGENE 500, Rhone Merieux, Lyon, France. Anes-
perimental group, cycling females were assigned to one of thesia prevented animal motility and agitation during the
three groups: estrous, diestrous and proestrous. The num- stimulation which obliged the operator to apply unwanted
ber of rats at each stage was 5. Statistical analysis of Fos skin stimulation to maintain the animal. A latex balloon
data in cycling, non-stimulated control rats, revealed no was inserted through the vagina at the vaginocervical level
differences due to estrous cycle. Five rats were then and then inflated via a catheter with 0.5 ml of water 20
selected randomly to form the control group of cycling mmHg to distend the wall for 10 min. To record vag-
females. inocervical contractions, the catheter was connected to a
In order to verify the effect of ovariectomy, ten females pressure transducer Telco M52. Pressure signal was sent
were ovariectomized
bilaterally under
Ketamine to a paper chart recorder CS 600. At the end of the
chlorhydrate anesthesia 100 mg kg via lumbar incisions. stimulation, the balloon was deflated and used to perform a
After a recovery of 4 weeks, 5 females received vag- vaginal smear.
inocervical stimulation and the 5 others were used as Control rats were lightly anaesthetized and handled as
ovariectomized, non-stimulated controls. long as the experimental group. No VCS was applied. The
vaginal smear was performed just before perfusion. After a surviving period of 60 min after the end of the
3. Results
