BIOLOGY OF SPERMATOZOA 



743 



TABLE 13.11 



Metabolic substrates in rabbit tubular fluid 



(From D. W. Bishop, Internat. J. Fertil., 



2, 11-22, 1957.) 



cretion and not merely a transudate from 

 the vascular system or overflow from the 

 peritoneal cavity. The presence of secre- 

 tory cells in the tubal epithelium is well 

 known; they undergo morphologic and ap- 

 parent physiologic alterations which paral- 

 lel changes in ovarian activity (Hadek, 

 1955, 1958a; Borell, Nilsson, Wersall and 

 Westman, 1956). In the rabbit the se- 

 cretion is regarded as essential for normal 

 development of the egg (Westman, Jorpes 

 and Widstrom, 1931), and it may be neces- 

 sary for the normal functioning of sper- 

 matozoa and the process of fertilization as 

 well (r/. Whitten, 1957). 



The secretory activity of the rabbit Fal- 

 lopian tube has been investigated and the 

 volume of flow and secretory pressure in 

 singly and doubly ligated tubes determined 

 (Bishop, 1956a). Mean tubal secretion rates 

 in lightly anesthetized estrous, pregnant, 

 and castrate rabbits were 0.79, 0.37, and 

 0.14 ml. per 24 hours, respectively. Secretory 

 activity was maximal at the time when the 

 spermatozoa are in the ampulla. Active se- 

 cretion, as opposed to passive diffusion or 

 transudation, was demonstrated by mano- 

 metric determinations of the pressures de- 

 veloped within a closed tubal system over 

 a 36-hour period. Pressure maxima in es- 

 trous, pregnant, and castrate rabbits aver- 

 aged 46.0, 15.6, and 11.8 cm. HoO, respec- 

 tively (Fig. 13.12). Both secretory volume 

 and pressure decreased from the 11th to the 

 21st day of pregnancy. Further indication 

 that tubal secretion is an active process is 

 shown by its sensitivity to pilocarpine; a 

 single injection of 1 mg. of pilocarpine hy- 

 drochloride almost doubled the secretory 

 pressure, to a value of 75 to 80 cm. HoO, in 

 estrogen-dominated animals (Fig. 13.13). 

 A program initiated by Clewe and Mast- 

 roianni (1959, I960) permits the continuous 



cm. HgO 



Fig. 13.12. Secretion pressures in rabbit oviducts. A, estrous; B, 14-da.v pregnant; C, 51- 

 day castrate, (from D. W. Bishop, Am. J. Physiol., 187, 347-352, 1956a.) 



