BIOLOGY OF SPERMATOZOA 



749 



paired health of the subjects. Three decades 

 after Darwin, the immunization of labora- 

 tory animals against spermatozoa suggested 

 a mechanism by which sensitization could 

 come about. During the following half cen- 

 tury the pros and cons of this issue were to 

 rage. The parenteral introduction of either 

 homologous or heterologous spermatozoa 

 was early claimed by many workers to in- 

 duce some degree of female sterility in a 

 wide variety of animals (see Parkes, 1944; 

 Tyler and Bishop, 1961). Some experiments 

 seemed so successful that a patent was once 

 granted for an antisterility preparation 

 based on this procedure (Baskin, 1937). 

 Such experiments, however, are beset with 

 difficulties of control and natural biologic 

 variation. It is not surprising, therefore, 

 that more recent investigations have tended 

 to discredit the earlier reports of sterility 

 induced by sperm injection, and to provide 

 adequate explanation for many of the ap- 

 l)arent positive results (Eastman, Gutt- 

 macher and Stewart, 1939; Hartman, 1939; 

 Henle and Henle, 1940; Lamoreux, 1940). 

 The ancient role of spermotoxins in inducing 

 female sterility seemed thus to be laid at 

 rest. 



The issue was again raised with the ad- 

 \ent of adjuvants which have the ability 

 of potentiating the effect of an antigenic 

 stimulus. Quite recently, evidence has ac- 

 crued indicating that reproductive capacity 

 may indeed be impaired in female rabbits 

 and guinea pigs when they are injected with 

 sjierm or testis homogenate combined with 

 adjuvant (Katsh and Bishoj), 1958; Isojima, 

 (h-aham and Graham, 1959; Katsh, 1959b). 

 In treated guinea pigs, the fertility (number 

 bearing litters) was reduced to 24 per cent 

 compared with 84 per cent for the controls. 

 The rate of fetal death and resorption was 

 high, but there seems to have been little 

 effect on ovulation or fertilization. High 

 titers of circulating antisperm antibodies 

 were present, but their connection with the 

 decreases in fertility is not clear. One 

 reasonable explanation for the occurrence 

 of these induced effects on reproductive ca- 

 pacity was suggested by Katsh (1957), who 

 attributed the fetal loss to a possible ana- 

 phylactoid response of the uterus to foreign 

 antigen. Other plausible mechanisms may 

 involve the gametes or develoi)ing embryos 



directly; circulating antibodies can pass 

 into the uterine and tubal fluids and might 

 impair development (McCartney, 1923). 



These recent results, then, not only give 

 some credence to the early claims for in- 

 duced sterility, but also raise the question 

 as to the possibility of naturally acquired 

 sensitization in breeding females. Little di- 

 rect evidence can be cited in support of such 

 a hypothesis since only fragmentary im- 

 munologic studies have been made which 

 indi'-.'ate sensitization or antisperm antibody 

 titers in the sera of animals not previously 

 inoculated (see Tyler and Bishop, 1961). 

 However, in a series of over 200 women, 

 Ardelt (1933) found a positive correlation 

 between frequency of coitus and comple- 

 ment-fixation titer against human sperma- 

 tozoa. Studies of this sort on various species 

 should ]irove rewarding. 



Whereas the evidence concerning the de- 

 gree of sensitization of the female is scant, 

 the means by which antigenic stimulation 

 might occur seems adequate. The penetra- 

 tion of the tubal epithelium by sperm has 

 been noted ; under some circumstances, this 

 phenomenon may be relatively common, as 

 when mild infections or lesions occur within 

 the tubal mucosa. Another possible site of 

 antigenic stimulation, particularly in ani- 

 mals like the rabbit, is the peritoneum, for 

 not only do sperm pass through the tract 

 and enter the body cavity (Hartman, 1939; 

 Home and Audet, 1958) , but the peritoneum 

 is an adequate site for antibody formation. 

 Furthermore, repeated deposition of sper- 

 matozoa into the rabbit vagina results in 

 high titers of circulating antisperm anti- 

 bodies (Pommerenke, 1928). A comparable 

 situation has also been demonstrated in 

 heifers in which genetically tagged erythro- 

 cytes, rather than sperm, were introduced 

 into the intra-uterine cavity, with the re- 

 sult that specific antibodies subsequently^ 

 appeared in the blood (Kiddy, Stone, Tyler 

 and Casida, 1959). These results have been 

 interpreted as demonstrating the passage 

 of antigen into the circulation where access 

 is gained to the sites of antibody formation ; 

 it is to be noted, however, that the tissues 

 of the reproductive tract itself do on oc- 

 casion produce antibodies (Kerr and Rob- 

 ertson, 1953). It is worth pointing out that, 

 in other experiments, antibodies, rather than 



