Effect of CNP additive to diluents during capacitation on live percentage and pH of bull epididymal spermatozoa.

Abstract

 Abattoir male gonads specimens were collected from Al-Shoáalla abattoir from June 2019
until November 2019 in an average of 2 visits per week. This study was designed to evaluate
the optimum effect of C-type natriuretic peptide on the caudal epididymal spermatozoa
characteristics from a healthy slaughter bull. Dissected and separated the epididymis from
the entire testicle made by a small scissor. The caudae were injected with 5-8 ml of the
TCM199 media containing 100 IU/ml penicillin-streptomycin and 100 IU/ml Nystatin using
an 18 gauge needle attached toa 5-ml syringe then aspirated. After collection of Spermatozoa
samples of cauda epididymis were evaluated under the light microscope has individual
motility less than 70% of were rejected. The caudal epididymal Spermatozoa samples
transported from petri dish to a 10 ml test tube containing 2 ml maturation media (TCM199)
that contain 100 IU/ml penicillin-streptomycin and 100 IU/ml Nystatin; the test tube
incubated in a 5% CO2 incubator at 39 Cº for 4 hours for sperm maturation, the presence of
distal protoplasmic droplet was the criteria of sperm maturation. Then the samples divided
into three equal groups control one, low concentration 10-7 mol/L, and high concentration 10-
6 mol/L. It evaluated the effect of C-type natriuretic peptide (CNP) during capacitation on the
live percentage and pH of bull epididymal spermatozoa. The live percentage and pH of
sperm were analyzed at 5 min, 10 min, 15 min, 30 min, 45 min, 60 min, 120 min, and 180 min
for each group. A total of 20 caudal epididymides were studied during the period of the
experiment. Evaluation of spermatozoa parameters as a stained smear for dead and alive
spermatozoa was conducted in addition to pH; all results were recorded.   The pH of the semen was measured immediately after the recovery of sperms from the
epididymal by using a pH litmus paper. A drop of sperms suspension on a glass slide, a
drop of Eosin-Negrosin stain was added and mixed. Two smears of each sample were
made when each smear dry it was mounted immediately under coverslip using DPX; 200-
400 sperms were examined in each smear on a light heated stage microscope at 40x
objective power. The final percentage was calculated by taking the average of two smears.
The results of herein study of live percentage in bull epidydimal sperm during the
capacitation of control group indicate that the significant changes at the level of (P<0.05)
in the control group started within 30 minutes after capacitation while the significant
changes starting at level (P<0.05) in low (10-7) mol/L and high (10-6) mol/L
concentration with 45 minutes after capacitation to the end of the experiment as well as
there were no significant differences between the three studied groups. In contrast, the
results of a novel study of pH in bull epidydimal sperm during the capacitation of the
control group indicate that the significant changes of pH at the level of (P<0.05) begins
within 10 minutes after capacitation while the significant changes starting at level
(P<0.05) in low and high concentration with 45 minutes after capacitation to the end of
the experiment. At the same time, there were significant differences (P<0.05) between low
and high concentration with the control group recorded during the period 45 minutes and
lasted until the end of the experiment. The conclusion that there were no changes between
control and treated groups in live percentage, and also there was a positive improvement
in treated groups in live and pH after capacitation with CNP additive to epididymis
sperms.