Sperm evaluation and biochemical characterization of cat seminal plasma collected by electroejaculation and urethral catheterization

This paper aimed to evaluate cat seminal plasma protein profile (with SDS-page) and determine differences in seminal plasma composition from ejaculates obtained using urethral catheterization after pharmacological induction (UrCaPI) and electroejaculation (EE). In addition, this study evaluates whether the recovery method affected seminal plasma protein and zinc concentrations. A single ejaculation was collected from 17 mixed-breed cats by EE (5/21) or UrCaPI (12/21), while 4/21 cats underwent four sperm collections once every four days using EE and UrCaPI techniques alternately. The semen parameters evaluated were: volume, percentage of motility and progressive motility, morphology, and sperm concentration. After centrifugation, the seminal plasma obtained was stored at -80 °C and later used to measure protein and zinc concentrations, and to determine protein profile by SDS-polyacrylamide gel electrophoresis (PAGE). The results obtained indicate that cat seminal plasma protein profile is characterized by many protein bands (>30) with a molecular weight ranging from 3.5 to 200 kDa, and that the recovery method influences the seminal plasma protein profile: EE is related to the absence of two proteins (P55 and P14), and alters three protein bands (P200, P80, P28). The collection technique also affected zinc concentration (mg/dL) and protein concentration (g/dL) which were significantly higher (P < 0.01) in samples collected by UrCaPI; on the contrary the total Zn and protein amount/ejaculate were not significantly different in samples collected by both technique (P < 0.05).