Acrosin inhibitor BSTI-I in seminal and/or blood plasma of male and female pigs under different reproductive conditions Academic Article uri icon


  • Boar seminal plasma trypsin-acrosin inhibitor I (BSTI-I) concentrations were measured by homologous radio-immunoassay: 1. In seminal and blood plasma of boars, before and after castration and following testosterone propionate administration (after castration); 2. In blood plasma of gilts, during the oestrous cycle and following insemination; and 3. In blood plasma of sows at the time of weaning. Firstly, it was demonstrated that the blood-plasma component, measured by the radio-immunoassay, is indeed BSTI-I. The main goal of the study was to determine BSTI-I concentrations during different reproductive stages and to evaluate the possibilities for using these measurements in fertility studies. In boars, BSTI-I levels were testosterone dependent, in both the seminal plasma and circulation, as shown by their response to castration and testosterone propionate administration. The blood-plasma BSTI-I level appeared to be sex dependent. In all animals measured so far, the lowest concentration measured in a group of non-castrated males was 1.5 times the highest concentration measured in a group of non-inseminated females. Between females, considerable differences in the endogenous bloodplasma BSTI-I level were observed. In gilts, the endogenous blood-plasma BSTI-I concentration showed no clear relationship with the phase of the oestrous cycle. In sows, a highly significant increase in the BSTI-I concentration was found during a 5-day period following weaning. After insemination, the seminal plasma BSTI-I was found to be absorbed and could be detected in the circulation. The highest blood-plasma levels of this exogenous BSTI-I were reached at about 4 h after insemination. Absorption of seminal-plasma BSTI-I varied during the period of oestrus; however, no relationship between blood-plasma BSTI-I concentrations and the fertilization rate and embryonic survival could be demonstrated. The results presented here do not reveal indications that BSTI-I measurements in blood plasma can be used as a parameter in fertility studies. 1996 Blackwell Wissenschafts-Verlag,.

published proceedings

  • Reproduction in Domestic Animals

author list (cited authors)

  • Erkens, J., Johnson, L. A., & Van Der Lende, T.

complete list of authors

  • Erkens, JHF||Johnson, LA||Van Der Lende, T

publication date

  • December 1996