Biophysical study of mammalian sperm utilizing electron paramagnetic resonance

Junying Du, Purdue University

Abstract

The mammalian spermatozoa water volume, osmotic behavior, and glycerol permeability coefficient are necessary to model optimal cryopreservation protocols for the cryopreservation of mammalian sperm. In this study, human and bovine spermatozoa water volume, osmotic behavior, and glycerol permeability and mouse spermatozoa water volume and osmotic behavior were studied using an electron paramagnetic resonance (EPR) technique utilizing the spin label tempone and the broadening agent potassium trioxalatochromiate (chromium oxalate). A water volume of 20.0 $\pm$ 2.9 $\rm\mu m\sp3$, 21.3 $\pm$ 2.8 $\rm\mu m\sp3$, and 41.9 $\pm$ 3.5 $\rm\mu m\sp3$ (mean $\pm$ SD) were obtained for human spermatozoa, bovine spermatozoa, and mouse spermatozoa; respectively. The osmotic behavior was determined to be linear in the range of 250 to 1500 mOsm for human spermatozoa, in the range of 122 to 1500 mOsm for bovine spermatozoa, and in the range of 250 to 900 mOsm for mouse spermatozoa, respectively. The permeabilities of human spermatozoa in 1 molar and 2 molar glycerol at 20$\sp\circ$C were 10.3 $\pm$ 0.3 $\times\ 10\sp{-4}$ cm/min. and 6.0 $\pm\ 1.4 \times 10\sp{-4}$ cm/min., respectively. The permeabilities of human spermatozoa in 2 molar glycerol at 30$\sp\circ$C, 20$\sp\circ$C, 10$\sp\circ$C, and 0$\sp\circ$C were 8.3 $\pm\ 1.3 \times 10\sp{-4}$ cm/min., 6.0 $\pm\ 1.4 \times 10\sp{-4}$ cm/min., 2.1 $\pm\ 0.4 \times 10\sp{-4}$ cm/min., and 1.13 $\pm\ 0.3 \times 10\sp{-4}$ cm/min., respectively. The permeabilities of bovine spermatozoa in 2 molar glycerol at 20$\sp\circ$C, 10$\sp\circ$C, and 6$\sp\circ$C were 11.5 $\pm\ 2.4 \times 10\sp{-4}$ cm/min., 6.4 $\pm\ 2.2 \times 10\sp{-4}$ cm/min., and 3.5 $\pm\ 0.9 \times 10\sp{-4}$ cm/min., respectively. The activation energy (Ea) for glycerol permeation between 30 and 0$\sp\circ$C was found to be 11.6 kcal/mole for human spermatozoa and the activation energy (Ea) for glycerol permeation between 20 and 6$\sp\circ$C was found to be 13.1 kcal/mole for bovine spermatozoa.

Degree

Ph.D.

Advisors

Kleinhans, Purdue University.

Subject Area

Biophysics|Cellular biology

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