title: Direct observation of cold-shock effects in ram spermatozoa with the use of a programmable cryomicroscope.
abstract: Cryoinjury in individual ram spermatozoa was investigated in cells cooled at 10 degrees C/min on a programmable cryomicroscope. In physiological buffer and cryoprotective media, there was a smooth decline in sperm swimming speed with decreasing temperature; cooling in buffer caused a marked decline in the proportion of cells displaying forward progression, especially once the temperature fell below 16 degrees C. Spermatozoa cooled in the presence of rhodamine 123, a mitochondrial-specific dye, showed that abolition of sperm motility by cold shock in buffer was not due to mitochondrial inactivation. Temperature decline through the region of 10 degrees C caused a number of spermatozoa in buffer to undergo a sudden asymmetric bending of the flagellum in the region of the midpiece. Ultrastructural studies suggest that this was caused by an unstable, asymmetric membrane lesion. Spermatozoa cooled in the presence of cryoprotective media showed better recovery of motility after rewarming and failed to exhibit the bending effect described above.
authors.affiliation: Institute of Zoology, Zoological Society of London, England.
authors.forename: W V
authors.initials: WV
authors.lastname: Holt
authors.forename: G J
authors.initials: GJ
authors.lastname: Morris
authors.forename: G
authors.initials: G
authors.lastname: Coulson
authors.forename: R D
authors.initials: RD
authors.lastname: North
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects*; D008297:Male; D008853:Microscopy / Q000379:methods; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000378:metabolism; D020112:Rhodamine 123; D012235:Rhodamines; D012756:Sheep; D013081:Sperm Motility; D013082:Sperm Tail / Q000473:pathology; D013094:Spermatozoa / Q000473:pathology* / Q000502:physiology / Q000648:ultrastructure; D014741:Video Recording
chemical_list: D012235:Rhodamines; D020112:Rhodamine 123