Efectos de la pentoxifilina y la cafeína sobre la motilidad de espermatozoides bovinos criopreservados

Resumen

En el presente trabajo se probaron dos concentraciones de pentoxifilina (10 mM y 6 mM) y dos de cafeína (10 mM y 6 mM), adicionadas a un medio de cultivo definido de amplio uso en fertilización in vitro (FIV), TCM 199.

Se trabajó con un 'pool' de pastillas de semen pertenecientes a 6 toros diferentes, descongelándose dos pastillas por repetición, realizándose 5 repeticiones. El semen reconstituido se colocó en baño a 37°C, observándose a distintos tiempos postdescongelamiento (0', 15' , 30', 60', 120' y 180'). Se determinó el porcentaje de células mótiles y el vigor de las mismas, en una escala de 5 puntos.

El análisis estadístico se realizó mediante una ANDEVA para un diseño completamente al azar y posteriormente se efectuó un test de Duncan.

Los resultados obtenidos indican que a partir de los 30' existirían diferencias significativas para motilidad entre los tratamientos con pentoxifilina y con 10 mM de cafeína respecto al testigo y al de 6 mM de cafeína. Similar respuesta se observa en el caso del vigor a partir de los 120'. Los tratamientos con diferentes concentraciones de cafeína arrojaron diferencias significativas entre ellos, no así las distintas concentraciones de pentoxifilina.

Puede concluirse que el agregado de 6 mM de pentoxifilina o 10 mM de cafeína permitirían prolongar en el tiempo la viabilidad del semen congelado posteriormente a su reconstitución, resultando esto de interés para su utilización en FIV.

Palabras clave: semen bovino, criopreservación, pentoxifilina, cafeína, hiperactividad.

Abstract

Stimulating effects of caffeine(C8H10N402) and pentoxifylline (C13H18N403) on the recently eyaculated spermatozoos motility are known. However, previous studies showed that 6 MM of caffeine were not efficient when utilized on frozen bovine semen.

In this research, 10 mM and 6 mM pentoxifylline concentrations, and the same of caffeine, were proved, by addition in a widely used 'in vitro' fertilization (IVF) culture medium, TCM 199.

A 'pool' of six bulls semen pills were defrosted, two pills for time, in five repetitions. Reconstituted semen was placed in water bath at 37°C, and was observed in differents post-defrosted times (0', 15', 30', 60', 120', 180'). The motility and vigor cells percentages were determined, with a scale of 5 points.

Statistical analysis was carried out by means of an ANOVA for a completely randomized design and then subsequently a Duncan's test was done.

The results suggest that starting from 30', significant differences in motility would exist among treatments with pentoxifylline and with 10 mM of caffeine respect to witness and to 6 mM of caffeine, and that starting from the 120', similar answer is observed about vigor. Significant differences were observed between the different caffeine concentration treatments, but they were not found for pentoxifylline.

The conclusion is that the addition of 6 mM of pentoxifylline or 10 mM of caffeine would allow to prolong the viability of frozen semen subsequently to its reconstitution. These results are interesting for its usage in IVF.

Key words: bovine sperm, criopreservation, pentoxifylline, caffeine, hiperactivity.