PERMEABILITY OF MACAQUE SPERM AT SUBZERO TEMP IN PRESENCE OF EXTACELLULAR ICE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 背景：在目前的研究中，我们报道了在冷冻保护剂甘油存在和不存在的情况下，冷却射精和附睾猴(猕猴)精子的效果。方法：在无任何冷冻保护剂和0.7M甘油存在的条件下，以20℃/min的降温速度获得精液和附睾液冷冻过程中的水传输数据。根据之前公布的数值，猕猴精子细胞被建模为一个圆柱体，长度为73.83？m，半径为0.40？m，渗透不活跃细胞体积Vb为0.772Vo，其中Vo是等渗细胞体积。这转化为表面积，SA与初始水体积，WV比~22？m-1。结果/讨论：通过将水传输模型与实验测定的体积收缩数据进行拟合，得出最佳的膜渗透参数(0℃、LPG或LPG[CPA]时的参比膜透水率和活化能ELP或ELP[CPA])的范围为：LPG或LPG[CPA]=0.00200.0029？m/min-ATM；ELP或ELP[CPA]=10.618.3千卡/摩尔。通过将这些膜渗透性参数纳入最近开发的方程(最佳冷却速度，Bopt？1009：5 x exp(-0.0546 x ELP)x(Lpg)x(SA/WV))；在Bopt单位为C/min，ELP或ELP[CPA]为千卡/摩尔，LPG或LPG[CPA]为m/min，SA/WV为m-1的情况下，我们确定猕猴精子的最佳冷冻速率为~23℃/min(无CPA的精液)、~29℃/min(有甘油的精液)、~24℃/min(无CPA的附性精子)和~24℃/min(有甘油的附性精子)。总而言之，在相应的冷却条件下，射出的精子和附睾精子的负温水分运输反应以及相应的负温水分运输参数没有显著差异。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Background: In the present study, we report the effects of cooling ejaculated and epididymal rhesus monkey (Macaca mulatta) sperm with and without the presence of a cryoprotective agent, glycerol. Methods: Water transport data during freezing of ejaculated and epididymal sperm cell suspensions were obtained at a cooling rate of 20 ¿C/min in the absence of any cryoprotective agents and in the presence of 0.7 M of glycerol, as well. Using previously published values, the macaque sperm cell was modeled as a cylinder of length 73.83 ¿m with a radius of 0.40 ¿m and an osmotically inactive cell volume, Vb, of 0.772Vo, where Vo is the isotonic cell volume. This translated to a surface area, SA to initial water volume, WV ratio of ~ 22 ¿m-1. Results/Discussion: By fitting a model of water transport to the experimentally determined volumetric shrinkage data, the best-fit membrane permeability parameters (reference membrane permeability to water at 0 ¿C, Lpg or Lpg[cpa] and the activation energy, ELp or ELp[cpa]) were found to range from: Lpg or Lpg[cpa] = 0.00200.0029 ¿m/min-atm; ELp or ELp[cpa]) = 10.618.3 kcal/mole. By incorporating these membrane permeability parameters in a recently developed equation (optimal cooling rate, Bopt ¿ 1009:5 x exp(-0.0546 x ELp) x (Lpg) x (SA/WV); where the units of Bopt are ¿C/min, ELp or ELp[cpa] are kcal/mole, Lpg or Lpg[cpa] are ¿m/min-atm and SA/WV are ¿m-1), we determined the optimal rates of freezing macaque sperm to be ~ 23¿C/min (ejaculated sperm in the absence of CPAs), ~29 ¿C/min (ejaculated sperm in the presence of glycerol), ~24 ¿C/min (epididymal sperm in the absence of CPAs) and ~ 24 ¿C/min (epididymal sperm in the presence of glycerol). In conclusion, the subzero water transport response and consequently the subzero water transport parameters are not significantly different between the ejaculated and epididymal spermatozoa under corresponding cooling conditions.