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|Title:||Female Reproductive Tract Fluids and Their Influence on Capacitation of Bovine Spermatozoa|
|Author(s):||Fazleabas, Asgerally Turabally|
|Department / Program:||Dairy Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Biology, Animal Physiology|
|Abstract:||Uterine, oviducal and follicular fluids were analyzed for protein, steroids and metabolic substrates based on stage of the cycle and follicular size respectively. Uterine fluids contained more protein than oviducal fluids and pyruvate and lactate concentrations in both fluids showed an inverse relationship based on the stage of the cycle. The steroid concentrations for the most part reflected the stage of the cycle. Protein and substrate concentrations in follicular fluids compared favorably with those of the serum controls. Estrogen and progesterone increased with increasing follicular size, while testosterone decreased in concentration. The proteins from all three fluids had predominantly acidic Pi, but their electrophoretic migration patterns differed markedly from one another. Compared against serum, fluids contained both serum proteins and fluid specific proteins indicating transfer and secretory activity by the organs.
Spermatozoa incubated in uterine and oviducal fluids showed marked increases in respiratory activity at 8 or 12 hours of incubation. Uterine fluids and control fluids with BSA (KRBB) were the most stimulatory. Acrosomal morphology was altered during incubation in fluids and controls. Spermatozoa in uterine fluids had primarily "late reacted" or no acrosome spermatozoa after 4 hours of incubation. Oviducal fluids, control fluids without BSA (KRB) and KRBB had cells undergoing "early acrosomal reactions" primarily up to 12 hours following which the acrosomal morphology was similar for spermatozoa incubated in all fluids for up to 18 hours.
Both soluble and membrane bound acrosomal proteins were altered during incubation. These changes observed in acrosomal proteins from spermatozoa incubated in KRB and KRBB for 12 or 18 hours were reflected in fluid incubated spermatozoa at 2 or 4 hours. These alterations affected both anodic and cathodic proteins and indicate that this may be one of the biochemical changes that is associated with spermatozoa undergoing capacitation. The protein alterations were similar in the presence of either uterine or oviducal fluids.
Acrosin activity was associated with both incubation media and acrosomal extracts. The decrease in activity in the acrosomal extracts over time were reflective of the increase in the incubation media. Oviducal fluids seem to contain an inhibitor for acrosin activity. Histochemical isolation on polyacrylamide gels revealed, initially, three forms of acrosin of which only one remained after 2 hours of incubation. Zymographic analysis indicated that these were all active forms and may have a cummulative effect on enzyme - substrate interactions.
Stage of the cycle from which the fluids were extracted did not seem to influence their effect of spermatozoal respiration, morphology or biochemistry. It is postulated that spermatozoa incubated in vitro in tract fluids initially undergo alterations in membrane bound and soluble acrosomal proteins accompanied by the conversion of proacrosin to three active forms of acrosin, only one of which persists following 2 hours of incubation. The spermatozoa then undergo the acrosome reaction, being most pronounced by 8 hours of incubation. Metabolic activity by spermatozoa increased at 8 or 12 hours. The changes at these incubation periods correspond to the time, in vivo, when spermatozoa are in the vicinity of the ovum and begin to penetrate the outer vestments of the egg. The initial biochemical changes may prepare the spermatozoa for the acrosome reaction, increase its metabolic activity and bring about the formation of the active form of acrosin for zona penetration. The changes observed in these in vitro studies with bovine spermatozoa relate closely to the changes involved in spermatozoa from other species that are undergoing capacitation.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
|Date Available in IDEALS:||2014-12-14|