Leptin and prolactin reduce cryodamage in normozoospermic human semen samples during cryopreservation / La leptina y la prolactina reducen el criodaño en muestras de semen humano normozoospérmico durante la criopreservación

Objectives: Cryopreservation has destructive effects on the function and structure of spermatozoa. It is known that leptin and prolactin play an active role in decreasing the rates of reactive oxygen species and DNA fragmentation, as well as enhancing sperm motility. Hence, this experiment aimed to investigate the effects of leptin and prolactin as pro-survival factors on the normozoospermic human semen samples during cryopreservation. Material and methods: Semen samples were collected from 15 healthy, fertile men ranging from 25 to 40 years. Cryopreservation of the samples was performed in liquid nitrogen over a period of two weeks, using five varying concentrations of leptin/prolactin, 0, 10, 100, 500, and 1000ng/ml respectively. Sperm motility, total caspase activity, and mitochondrial and cytosolic ROS were measured by flowcytometry, TUNEL, and other appropriate tests after thawing of the samples. Results: Both hormones were observed to have positive effects on the motility of the samples post-cryopreservation, the highest improvement being in the 100ng/ml concentration leptin and prolactin in comparison to the control group (P=0.01 and P=0.041, respectively). A significant reduction of mitochondrial ROS was also observed in 100 and 1000ng/ml of leptin (P=0.042), and there was a considerable decrease in the cytosolic ROS in the 100ng/ml of prolactin in comparison to the control group (P=0.048). Total caspase activity was also highly reduced in the 100, 500, and 1000ng/ml of leptin compared to the control group (P=0.039). Interestingly, both hormones also significantly decreased DNA fragmentation in 1000ng/ml compared to the control group (P=0.042). (AU)

Objetivos: La criopreservación tiene efectos destructivos sobre la función y estructura de los espermatozoides. Se sabe que la leptina y la prolactina desempeñan un papel activo en la disminución de las tasas de especies reactivas de oxígeno (ROS) y la fragmentación del ADN, así como en la mejora de la motilidad de los espermatozoides. Por lo tanto, este experimento tuvo como objetivo investigar los efectos de la leptina y la prolactina como factores de supervivencia en las muestras de semen humano normozoospérmico durante la criopreservación. Material y métodos: Se recolectaron muestras de semen de 15 hombres sanos y fértiles de entre 25 y 40 años. La crioconservación de las muestras se realizó en nitrógeno líquido durante un período de 2 semanas, utilizando 5 concentraciones variables de leptina/prolactina: 0, 10, 100, 500 y 1000ng/ml respectivamente. La motilidad de los espermatozoides, la actividad de caspasa total y las ROS mitocondriales y citosólicas se midieron mediante citometría de flujo, TUNEL y otras pruebas apropiadas después de descongelar las muestras. Resultados: Se observó que ambas hormonas tienen efectos positivos sobre la motilidad de las muestras después de la crioconservación, la mayor mejora se encuentra en la concentración de leptina y prolactina de 100ng/ml en comparación con el grupo de control (p=0,01 y p=0,041, respectivamente). También se observó una reducción significativa de las ROS mitocondriales en 100 y 1000ng/ml de leptina (p=0,042), y hubo una disminución considerable en las ROS citosólicas en los 100ng/ml de prolactina en comparación con el grupo de control (p=0,048). La actividad de la caspasa total también se redujo considerablemente en los 100, 500 y 1000ng/ml de leptina en comparación con el grupo de control (p=0,039). Curiosamente, ambas hormonas también redujeron significativamente la fragmentación del ADN en 1000ng/ml en comparación con el grupo de control (p=0,042). (AU)

Leptin and prolactin reduce cryodamage in normozoospermic human semen samples during cryopreservation.

OBJECTIVES: Cryopreservation has destructive effects on the function and structure of spermatozoa. It is known that leptin and prolactin play an active role in decreasing the rates of reactive oxygen species and DNA fragmentation, as well as enhancing sperm motility. Hence, this experiment aimed to investigate the effects of leptin and prolactin as pro-survival factors on the normozoospermic human semen samples during cryopreservation. MATERIAL AND METHODS: Semen samples were collected from 15 healthy, fertile men ranging from 25 to 40 years. Cryopreservation of the samples was performed in liquid nitrogen over a period of two weeks, using five varying concentrations of leptin/prolactin, 0, 10, 100, 500, and 1000ng/ml respectively. Sperm motility, total caspase activity, and mitochondrial and cytosolic ROS were measured by flowcytometry, TUNEL, and other appropriate tests after thawing of the samples. RESULTS: Both hormones were observed to have positive effects on the motility of the samples post-cryopreservation, the highest improvement being in the 100ng/ml concentration leptin and prolactin in comparison to the control group (P=0.01 and P=0.041, respectively). A significant reduction of mitochondrial ROS was also observed in 100 and 1000ng/ml of leptin (P=0.042), and there was a considerable decrease in the cytosolic ROS in the 100ng/ml of prolactin in comparison to the control group (P=0.048). Total caspase activity was also highly reduced in the 100, 500, and 1000ng/ml of leptin compared to the control group (P=0.039). Interestingly, both hormones also significantly decreased DNA fragmentation in 1000ng/ml compared to the control group (P=0.042). CONCLUSION: It can be concluded that leptin and prolactin act as protective agents against cryodamage to spermatozoa during cryopreservation.