Biol Reprod Lalor Postdoctoral Fellowships -- Application Deadline January 15, 2009
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Curry, M. R.
Right arrow Articles by Watson, P. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Curry, M. R.
Right arrow Articles by Watson, P. F.
Agricola
Right arrow Articles by Curry, M. R.
Right arrow Articles by Watson, P. F.

Biology of Reproduction, Vol 51, 1014-1021, Copyright © 1994 by Society for the Study of Reproduction

ARTICLES

Calculated optimal cooling rates for ram and human sperm cryopreservation fail to conform with empirical observations

MR Curry, JD Millar and PF Watson
Department of Veterinary Basic Sciences, Royal Veterinary College, London, United Kingdom.

The permeability coefficient to water (Lp) and its associated activation energy (Ea) were measured for ram (8.47 microns/min/atm at 25 degrees C, 1.06 kcal/mol) and human (2.89 microns/min/atm at 30 degrees C, 1.93 kcal/mol) spermatozoa. By use of these figures, predictive water loss curves were calculated, from published equations, for different cooling rates from 100 degrees C/min to 100,000 degrees C/min. The calculated curves show that ram spermatozoa cooled at even the fastest rate would be in osmotic equilibrium by -20 degrees C, and human spermatozoa cooled at rates up to 10,000 degrees C/min would be in equilibrium by -15 degrees C. If the nucleation temperature for spermatozoa is taken to be between -20 degrees C and -30 degrees C, then ram and human spermatozoa cooled at these rates would apparently not exhibit any intracellular freezing. There is a significant discrepancy between these calculated optimal cooling rates and the published empirically derived optimal rates of 50 degrees C/min for ram and 10 degrees C/min for human. The failure of ram and human spermatozoa to conform with the established and previously successful model for prediction of optimal cooling rates suggests that damage sustained at high cooling rates may be unrelated to intracellular ice formation.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1994 by the Society for the Study of Reproduction.