The plasma membrane contributes to temperature-induced spermatozoa motility kinetics in short-term stored sperm of common carp (Cyprinus carpio)

Spermatozoa motility kinetics have been found to increase in short-term stored sperm on ice of common carp (Cyprinus carpio) following incubation at a high temperature (20 degrees C) for 10-20 min. The aim of the present study was to elucidate the contribution of the ATP store and plasma membrane function in temperature -induced motility kinetics of short-term stored sperm. Spermatozoa ATP content significantly decreased after 9 days of short-term storage on ice; however, it remained unchanged after incubating stored sperm at higher temperatures. Spermatozoa motility kinetics of either fresh or stored sperm on ice for 14 days were enhanced following incubation or activation at 20 degrees C. The motility of demembranated spermatozoa from 14 days of stored sperm could be nearly fully activated, similar to that of fresh spermatozoa. The swelling ratio of spermatozoa incubated and activated at high temperatures was higher than that at low temperatures. Spermatozoa swelling was observed to be faster from sperm stored for 14 days than fresh sperm at the same incubation and activation temperature. These results suggest a physiological contribution of the plasma membrane to enhance spermatozoa motility kinetics in stored sperm following incubation at 20 degrees C.