The objective of this study was to determine a value of serum progesterone (P4) concentration, assessed using an enzymeimmunoassay (EIA), for the early distinction between pregnant and non-pregnant ewes and goats. Adult, non-lactating ewes of Chios (n=53), Berrichon (n=30) and Sfakia (n=45) breeds were synchronized during the breeding season with progestagens and gonadotrophins and mated to fertile rams (Experiment I). Adult, lactating goats of Swiss breeds (Alpine and Saanen, n=104) and indigenous Greek breed (n=45) were synchronized during the transitional season with progestagens, PGF2alpha and gonadotrophins. Cervical artificial insemination (AI) with fresh semen was applied once, 42-44 h after sponge removal (Experiment II). Jugular blood samples were collected on day 19 after sponge removal (ewes) or on day 21 after AI (goats) and serum P4 concentration was determined by EIA. Progesterone concentrations >/=1.0, >/=1.5, >/=2.5 and >/=4.0 ng/ml were tested as indicative of pregnancy. Pregnancy diagnosis was verified on birth. In the case of sheep, using a discriminatory level of 2.5 ng/ml, overall accuracy of pregnancy diagnosis was 91.4% and predictive value of negative and positive diagnoses were 98.3 and 85.3%, respectively. In the case of goats, predictive value of negative diagnosis was 95.8 and 94.0% and predictive value of positive diagnosis 71.3 and 71.7%, for 1.5 and 2.5 ng/ml, respectively; overall accuracy was 79.2% using either level. The other discriminatory levels tested did not improve these results. A significant positive correlation was observed between P4 concentration and the number of lambs or kids born, and further analysis indicated that this relationship is not a simple linear function. Based on the results of this study, P4 concentrations of 2.5 ng/ml in the case of ewes and 1.5-2.5 ng/ml in the case of goats, determined with EIA, are proposed as discriminatory levels between pregnant and non-pregnant animals, at an interval of one oestrous cycle after service.

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After a single injection of serum gonadotrophin (PMSG) at the dose of 15 IU/kg, i.m. into rams testosterone in the plasma of blood showed a significant rise between 4th and 7th day post-injection. At the same time (4th-7th day) the plasminogen activator activity (PAA) in seminal plasma was found to be increased, but the plasminogen activator inhibition (PAI) expressed against t-PA (anti-t-PA) showed an increase between 32nd and 46th day. In spermatozoa a marked increase of PAA was revealed between 32nd and 46th day postinjection, while an increase of PA1 (anti-t-PA) was exhibited on the 74th day. Plasmin inhibition (PI) in seminal plasma and spermatozoa showed no change compared to controls. A positive correlation has been found between increased concentrations of testosterone and PAA or PA1 (anti-t-PA) in spermatozoa and seminal plasma. The induced increase of PAA in spermatozoa under the effect of testosterone might be of physiological importance, since PAA is localized to sperm membranes and might participate in the whole process of fertilization. not the acrosome reaction. J Reprod Fertil 65:185-194 Fritz IB, Karmally K (1983) Hormonal influences on formation of plasminogen activator by cultured testis tubule segments at defined stages of the cycle of the seminiferous epithelium. Can J Biochem Cell Biol 61:553-560 Garnier D-H, Cotta Y, Terqui M (1978) Androgen radioimmunoassay in the ram: results of direct plasma testosterone and dehydroepiandrosterone measurement and physiological evaluation. Ann Biol Anim Biochem Biophys 18 (2A):265-281 ANDROLOGIA 23, 273-278 (1991) 278 C. REKKAS ET AL. Huarte J, Belin D, Bosco D, Sappino A-P, Vassalli J-D (1987) Plasminogen activator and mouse spermatozoa: Urokinase synthesis in the male genital tract and binding of the enzyme to the sperm cell surface. J Cell Biol 104: 128 1-1289 Juhan-Vague I, Moerman B, De Cock F, Aillaud MF, Collen D (1984) Plasma levels of a specific inhibitor of tissue-type plasminogen activator (and urokinase) in normal and pathological conditions. Thromb Res 33:523-530 Kaminski JM, Bauer L, Mack SR, Anderson RA, Waller DP, Zaneveld LJD (1986) Synthesis and inhibition of human acrosin and trypsin and acute toxicity of aryl 4-guanidinobenzoates. J Med Chem 29:514-519 Kaminski JM, Mack SR, Zaneveld LJD (1988) A critical assessment of the interaction between active site inhibitors and proacrosin. Biol Reprod 38 (Suppl 1):342 Kirchheimer J, Binder BR (1983) Localization and immunological characterization of plasminogen activators in human prostate tissue. Haemostasis 13:358-363 Kokolis N (1990) Effect of orchidectomy on tissue plasminogen activator activity, plasminogen activator inhibition and plasmin inhibition. Haemostasis 20:233-240 Kramer JM, Ericson RP (1982) Analysis of stage-specific protein synthesis during spermatogenesis by two-dimensional gel electrophoresis. J Reprod Fertil 64:139-143 Lacroix M, Fritz IB (1982) The control of the synthesis and secretion of plasminogen activator by rat Sertoli cells in culture. Mol Cell Endocr 26:247-258 Lac...