Effect of heparin and chondroitin sulfate on the acrosome reaction and fertility of bovine sperm in vitro.
Glycosaminoglycans (GAGs) were reported to induce acrosome reactions (AR) in epididymal and ejaculated bovine sperm (4,5). The GAGs chondroitin sulfate A (CS-A) and heparin were tested on ejaculated bovine sperm for their ability to increase in vitro fertilization (IVF) frequencies. Regardless of treatment, a sperm-egg incubation time of 18 hr was sufficient to achieve maximal rates of fertilization. The IVF frequency of sperm incubated 6 hr with 10 mug/ml heparin (116 173 , 67%) was increased (P<0.05) above control levels (56 181 , 31%); however, 10 mug/ml CS-A (56 164 , 34%) was without effect (P>0.05). In contrast to previous reports, CS-A did not (P>0.05) induce AR in ejaculated (9.5-hr incubation) or epididymal sperm (22.5-hr incubation). Linear increases in fertilization frequency (40% to 81%; P=0.001) and AR (9% to 32%; P</=0.05) occurred with time of sperm exposure to heparin (15 sec to 6 hr) suggesting a direct effect of heparin on sperm. Glucose interfered with the effect of heparin on sperm. These data show heparin can prepare sperm for AR and fertilization in vitro and suggest that heparin-like material present in the female bovine reproductive tract may play a role in vivo in sperm capacitation and fertilization.
Parrish
J J
JJ
Department of Meat and Animal Science University of Wisconsin Madison, WI 53706 USA.
Susko-Parrish
J L
JL
First
N L
NL