The aim of the present study was to investigate the effect of melatonin on plasminogen activator activity (PAA), plasminogen activator inhibition (PAI) and plasmin inhibition (PI) in ram spermatozoa and seminal plasma, in correlation with changes in blood testosterone. Melatonin implants (18mg) were placed subcutaneously in sixteen Chios rams in autumn and spring. Semen samples for spectrophotometrical assays were collected 36h before the implantation of melatonin and thereafter once a week, for 17 weeks. Blood samples for testosterone assay (RIA) were collected 8h before implantation (one sample/30min×7.5h) and thereafter every 15 days for 105 days after implantation. For each ram, six parameters of testosterone were estimated: mean value, basal level, number of peaks, peak amplitude, peak duration and mean testosterone concentration during peaks. Melatonin implantation during autumn induced an increase in PAA and t-PAI in spermatozoa; melatonin implantation in spring induced an additional increase in u-PAI and PI; no change in PAA, PAI or PI was found in seminal plasma, during autumn or spring. The melatonin-induced increase of PAA, PAI and PI in spermatozoa was in positive correlation with the increase of testosterone mean value, basal level and number of peaks; the increase of testosterone parameters was greater in autumn compared to spring. Changes of PAA, PAI and PI of spermatozoa, under the influence of melatonin, might indicate changes in the fertilizing ability of spermatozoa, since plasminogen activators and their inhibitors are present on the plasma and the outer acrosomal membrane of spermatozoa and are released during the acrosome reaction.

Synchronisation of oestrus in Karagouniki ewes by administration of the standard dose of progesterone results in lower fertility than observed when these ewes ovulate naturally. This suggests that the optimum dose of progesterone may be breed dependent. The exogenous progesterone may perturb the concentrations of oestradiol-17beta and progesterone in blood plasma and the oviductal wall. This possibility was investigated using Karagouniki ewes allocated at random to three treatments (n=4 per treatment). Ewes were allowed to exhibit natural oestrus (N) or oestrus was synchronised by administration of 250 mg (LP) or 375 mg (HP) progesterone (subcutaneous implants) followed by PMSG at 8 mg/kg live weight i.m. 14 days later. Oestrus was observed using teaser rams. Blood samples were collected for plasma oestradiol-17beta and progesterone assay from the onset to the end of oestrus at 2 h intervals. The uterus of each ewe was recovered at the end of oestrus and samples of the oviductal wall were taken from both oviducts and prepared, separately, for progesterone and oestradiol-17beta assay. Statistical analysis was performed using univariate analysis of variance. Plasma oestradiol-17beta concentrations from the onset to the end of oestrus were highest for N ewes and lowest for HP ewes with the values for LP ewes occupying an intermediate position. The differences were significant (P<0.05) between HP and the other two treatments from 4 to 12 h after the onset of oestrus and then between all treatments until the end of oestrus. Plasma progesterone levels were similar and fairly constant from the onset to the end of oestrus for N and LP. The plasma progesterone levels for HP were significantly (P<0.05) higher than for the other two treatments throughout oestrus. In oviductal wall samples, the oestradiol-17beta concentration was significantly (P<0.05) higher for N ewes than for synchronised ewes and the levels were similar for LP and HP ewes. The concentration of oestradiol-17beta differed (P<0.05) between right and left oviducts for N ewes but not for ewes of either of the synchronised oestrus treatments. Progesterone concentrations in oviductal wall samples were highest (P<0.05) for HP ewes and the values for N and LP ewes were similar. The concentration of progesterone did not differ between right and left oviductal wall samples within treatments. It was concluded that the higher dose of exogenous progesterone perturbed the levels of oestradiol-17beta and progesterone in blood plasma and the oviductal wall, and this could explain the lower levels of fertility (relative to naturally occurring oestrus) observed when this protocol is used for Karagouniki ewes in practice.

Organochlorine pesticides and polychlorinated biphenyls are widely used in agriculture and industry, respectively, and may affect male reproduction function. Although several pollutants have been detected in human semen, similar studies in farm animals have not appeared. In the present study, the semen of bulls, rams, goats, and boars was assayed for the organochlorine pesticides hexachlorobenzene (HCB), hexachlorocyclohexane (HCH, α-, β-, and γ-isomers), dieldrin, and heptachlor epoxide, for DDT-related chemicals (o,p′-DDE, p,p′-DDE, p,p′-DDD, p,p′-DDT), and for the PCBs congeners (PCB-52, -101, -138, -150, and -180). In all species of farm animals, the most frequently detected pollutants were p,p′-DDE (80–100% of samples), HCB (73.9–100%), and γ-HCH (69.6–100%). Species differences in the concentrations of HCB, α-, β-, and γ-HCH, dieldrin, p,p′-DDE, p,p′-DDD, and PCBs were noted as well as differences in the concentrations of some isomers of HCH, DDT-related chemicals, and PCB congeners in the same species.

Organochlorine pesticides and polychlorinated biphenyls are widely used in agriculture and industry, respectively. The present study assessed the burden of environmental pollutants in the follicular fluid of farm animals (cattle, sheep, goats, and pigs). An analytical method combining a solid-phase extraction with (C(18)) for clean-up and GC-electron capture detection using a capillary column was implemented for isolation and determination of organochlorine pesticides and polychlorinated biphenyls (PCBs). Of the organochlorine pesticides, hexachlorobenzene (HCB), hexachlorocyclohexane (HCH, alpha-, beta-, and gamma-isomers), dieldrin, heptachlor epoxide, and the DDT-related chemicals (o,p'-DDE, p,p'-DDE, p,p'-DDD, p,p'-DDT) were detected and of the PCBs, the congeners PCB-52, -101, -138, -153, and -180 were detected. In all species of farm animals, the most frequently detected pollutant was gamma-HCH (90-100% of samples) followed by HCB (80-100%), and p,p'-DDE (75-90.91%). Species differences in the concentrations of HCB, beta-HCH, heptachlor epoxide, and DDT-related chemicals in follicular fluid were noted as well as differences in the concentrations of some pollutants within the same species.

The objective of this study was to evaluate the effect of α-tocopherol on blood testosterone and specific proteolytic enzymes in spermatozoa and seminal plasma, with final aim the increase of sperm fertilizing ability with a nutritional supplement. The effect of α-tocopherol supplementation on testosterone parameters (mean value, basal level, peak number, mean concentration value during peaks, peak amplitude, peak duration) and plasminogen activator activity (PAA), plasminogen activator inhibition (PAI) and plasmin inhibition (PI) of spermatozoa and seminal plasma was studied in the ram during autumn (estrous period for the sheep in Greece) and spring (anestrous period). Treated animals showed a marked increase in serum α-tocopherol. Testosterone parameters were not affected by the α-tocopherol in either autumn or spring, however, the spermatozoal PAA and PAI (anti-tPA) were increased in the spring but not in autumn. These enzymes and their inhibitors are normally increased in autumn (the breeding season) and low in spring. If PAA can improve the fertilizing ability of spermatozoa in the spring, our finding may mean that a nutritional supplement, such as α-tocopherol, could provide rams for an accelerated onset of the breeding season in the ewe.

In a series of consecutive blood sampling in 15 days intervals over 15 weeks after implantation of melatonin in rams an increased mean value, basal level and number of peaks of testosterone was observed in samples of the third fortnight (45th day). This increase was greater in the autumn (breeding season) than in spring (non-breeding season). Total acrosin activity in spermatozoa was increased between days 35-56 (autumn) and days 49-70 (spring) after implantation and the relative increase was higher in autumn than in spring. The increase of acrosin activity was independent of the changes of testosterone. An increase of acrosin activity by melatonin, in cases of low activity, might improve fertilization rates in sheep not only during the breeding season, but also during the non-breeding season (after oestrus induction).

The aim of the study was to investigate the effect of dexamethasone on plasminogen activator activity (PAA), t-PA antigen level, plasminogen activator inhibition (PAI) and plasmin inhibition (PI) in ram lymphocytes. The PAA of ram lymphocytes was due to t-PA (tissue-type plasminogen activator), but not to u-PA (urokinase-type plasminogen activator). Dexamethasone at the dose of 3mgkg−1 increased the PAA and t-PA antigen level of lymphocytes within 2h after administration, while decreased the PAI 6–14h after administration; no change in PI was noted. When dexamethasone was administered at the dose of 0.75mgkg−1 every 4h for 12h, PAA and t-PA antigen level of lymphocytes showed an increase 2–6h after the end of the administration, while PAI and PI remained unchanged. These changes in PAA or PAI of lymphocytes, dependent on the dose or the pattern of dexamethasone administration, may be of importance regarding the role of lymphocytes and PAA or PAI in several pathophysiological conditions.

The effect of aspirin or endotoxin or aspirin plus endotoxin on the circadian variations of plasminogen activator activity (PAA), tissue-type plasminogen activator (t-PA) antigen level, plasminogen activator inhibition (PAI) and plasmin inhibition (PI) in aorta, heart and brain of the rat was studied. In aorta the circadian variations of PAA, t-PA antigen and tissue-type PAI (t-PAI) were blunted by endotoxin, while the circadian variation of PI was reversed; t-PAI variation was blunted by aspirin plus endotoxin, while PI variation was reversed. Various disturbances of the circadian variations of PAA, t-PA antigen, PAI or PI in heart and brain were also observed. In conclusion, the circadian variations of fibrinolytic parameters in key organs are influenced by aspirin or endotoxin or aspirin plus endotoxin in a varying way or degree depending on the treatment, the parameter studied or the organ.

Contents The concentrations of oestradiol‐17β and progesterone in the blood were studied during natural oestrus, synchronized oestrus, and the first oestrus after synchronized oestrus in four sheep breeds (Friesland, Chios, Serres and Karagouniki). During natural oestrus, significant variations of oestradiol‐17β concentration were only seen in Karagouniki ewes; during synchronized oestrus, oestradiol‐17β concentration in the blood showed a gradual decrease in all breeds. However, during the first oestrus after synchronized oestrus, the concentration of oestradiol‐17β in the blood returned to normal in all but the Serres breed. The concentration of progesterone in the blood showed no variation during natural oestrus, but, during synchronized oestrus, significant variations of progesterone in the blood were seen in all but the Serres breed. During the first oestrus after the synchronized oestrus, the progesterone in the blood returned to the natural‐oestrus levels with, however, some differences among the breeds. Oestrous synchronization therefore disturbed the con‐centration of oestradiol‐17P and progesterone in the blood of the ewe in a varying way, depending on the breed.

Inhalt Vergleichende Untersuchungen ovarieller Steroide im Blut sowie spezifische proteolytische Enzyme im Zervikalmukus bei vier Schafrassen nach Östrussynchronisation (Progesteron und PMSG). 2. Rassebedingte Unterschiede für PAA, PAI und PI im Zervikalmukus während des normalen und des synchronisierten Östrus sowie des ersten Östrus nach der SynchronisationPlasminogen‐Aktivator‐Aktivität (PAA), Plasminogen‐Aktivator‐Inhibition (PAI) und Plasmin‐Inhibition (PI) wurden im Zervikalmukus von vier verschiedenen Schafrassen (Friesland, Chios, Serres, Karagouniki) während des normalen und synchronisierten Östrus sowie des ersten Östrus nach der Synchronisation untersucht.PAA‐Konzentrationen stiegen in der Mitte des normalen Östrus an. Dabei traten rassespezifische Unterschiede auf. Ebenfalls rasseabhängig war die Veränderung von PAA im Zervikalmukus bei synchronisierten Tieren. Diese Veränderung bestand auch im ersten Östrus nach der Synchronisation bei allen Rassen außer bei Friesland‐Schafen. Es traten beide Typen des des Plasminogen‐Aktivator (t‐PA und u‐PA) auf.Rasseabhängig stieg PAI zur Mitte und am Ende des normalen Östrus an. Östrus‐Synchronisation veränderte PAI. Diese Veränderung hielt auch während des auf die Synchronisation folgenden Östrus an.PI stieg zum Ende des natürlichen Östrus an, wobei einige Rasseunterschiede beobachtet wurden. Im synchronisierten Östrus veränderten sich die PI‐Werte im Zervikalmukus. Außer bei Friesland‐Schafen hielt diese Veränderung des PI während des ersten Zyklus nach der Synchronisation an.Die Blutkonzentrationen von Östradiol‐17ßübten im begrenzten Maße bei einigen Rassen einen positiven Effekt auf PAA bzw. PAI und einen negativen Effekt auf PI im Zervikalmukus aus.

Plasminogen activator activity (PAA), tissue-type PA (t-PA) antigen level, plasminogen activator inhibition (PAI), and plasmin inhibition (PI) showed no sex-dependent differences in the stomach of the rat. Chronic ethanol consumption induced an increase of PAA and t-PA antigen and a decrease of PAI (urokinase-type PA [u-PAI]) and PI in the body and pyloric region (PI only in the pyloric region). PAA increase and u-PAI decrease in the pyloric region were greater in the male than in the female. Orchidectomy, but not ovariectomy, induced effects similar to those of ethanol. The effects of orchidectomy and chronic ethanol consumption on gastric PAA, t-PA antigen, and PAI were additive. An increased PAA and decreased PAI or PI in the stomach in cases of hypogonadism, particularly if this deficiency is combined with chronic ethanol consumption, might influence the susceptibility to pathological conditions related to or affected by the local fibrinolytic activity (PAA, PAI, or PI).

Plasminogen activator activity (PAA) and plasminogen activator inhibition (PAI), against t-PA (t-PAI) or u-PA (u-PAI), in spermatozoa and seminal plasma as well as testosterone in the blood of Friesland, Chios, and Karagouniki rams all showed a seasonal variation with the highest values during the corresponding breeding season of the ewes (Autumn-Winter). The seasonal variation of PAA and PAI in spermatozoa or seminal plasma as well as blood testosterone was different among the three breeds studied. Increased spermatozoal PAA was observed in November and May in Friesland rams, in October and November in Chios rams, and in October in Karagouniki rams. Spermatozoal t-PAI was increased in December and June in Friesland rams, in November and December in Chios rams, and in November in Karagouniki rams. Spermatozoal u-PAI was increased in December in Friesland rams, in October and December in Chios rams, and in November and December in Karagouniki rams. Plasminogen activator activity and PAI in seminal plasma also showed similar seasonal variations. Plasminogen activator activity and PAI in spermatozoa and seminal plasma showed a positive correlation with blood testosterone. The results of the present study support our previous findings on the possible role of spermatozoal PAA and PAI in the fertilizing ability of spermatozoa.

Plasminogen activator activity (PAA), t-PA antigen level, plasminogen activator inhibition (PAI) and plasmin inhibition (PI) showed a circadian variation in rat aorta, heart, brain, and lungs of both sexes, but in a different way depending on the organ and the fibrinolytic parameter studied and the sex as well. In general, the lowest values of PAA and t-PA antigen were found in the early morning and the highest values in late afternoon, while PAI or PI showed the opposite pattern (with the exception of lungs). In kidneys and liver the fibrinolytic parameters studied showed no circadian variation. Sex-related differences, mostly quantitative, were noted in aorta, heart, brain and kidneys, with lower PAA and t-PA antigen and higher PAI or PI in the male than in the female.

We have recently shown that spermatozoa of various species contain both types of plasminogen activator, the tissue-type (t-PA) and the urokinase-type (u-PA). In the present study, the localization of t-PA and u-PA in plasma membrane and outer acrosomal membrane of human and boar spermatozoa has been investigated. The identification of the type of the plasminogen activator (t-PA or u-PA) was made immunologically. In human spermatozoa, the outer acrosomal membrane and plasma membrane contained both types of plasminogen activator (t-PA and u-PA); in addition, t-PA antigen was measured. In boar spermatozoa, the outer acrosomal membrane contained only t-PA, whereas plasma membrane contained both types of plasminogen activator (t-PA and u-PA). Plasminogen activator inhibition (PAI) has also been demonstrated in plasma and outer acrosomal membranes of both species and identified as PAI-1 in membranes of human spermatozoa.

In normal Friesland rams, plasminogen activator activity (PAA) and plasminogen activator inhibition (PAI) in spermatozoa and seminal plasma, plasmin inhibition (PI) in seminal plasma and testosterone concentration in blood all showed seasonal variation. In a Friesland ram with chromosomal chimaerism XX/XY, however, although PAA, PAI and PI in seminal plasma and testosterone in the blood exhibited the same seasonal variation as in normal rams, in spermatozoa the PAA and PAI showed no seasonal variation. This is the first case in which a chromosomal anomaly has been linked with abnormal patterns in PAA and PAI.

In the normal stomach of male rats marked differences in plasminogen activator activity (PAA) and plasmin inhibition (PI), but not in plasminogen activator inhibition (PAI), were noted among cardiac area, body and pyloric region. Chronic ethanol consumption (for 15 or 30 days) at the concentration of 6% or 12% in the drinking water induced an increase in PAA in the pyloric region and the body of the stomach (the higher concentration after 15 days and both concentrations after 30 days). The response was time- and dose-dependent. At the cardiac area no change of PAA was noted. Ethanol at both concentrations induced after 30 days a decreased PAI in the pyloric region and the body of the stomach, which was expressed against u-PA, but not against t-PA. A decreased PI was noted at both concentrations of ethanol after 30 days only in the pyloric region. Therefore, changes in PAA, PAI and PI after chronic ethanol consumption were dependent on the concentration, the period of the consumption and the area along the gastric wall.

The effect of unilateral and bilateral adrenalectomy, unilateral and bilateral demedullation or unilateral adrenalectomy/unilateral demedullation on tissue plasminogen activator activity (PAA), plasminogen activator inhibition (PAI) and plasmin inhibition (PI) was studied in the rat. All the above treatments induced an increase of PAA in lungs. Increased PAA was also noted in brain after bilateral adrenalectomy or demedullation, as well as unilateral adrenalectomy/unilateral demedullation. In kidneys the PAA was decreased after bilateral adrenalectomy or demedullation and unilateral adrenalectomy/unilateral demedullation. In aorta only after bilateral adrenalectomy a decreased PAA was induced. In heart and liver no changes in PAA were noted. A decreased PAI expressed against tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) was found in lungs of all treated rats compared to controls. However, an increased PAI was noted in heart, liver and aorta against t-PA or u-PA after bilateral adrenalectomy and in liver after bilateral demedullation as well as after unilateral adrenalectomy/unilateral demedullation (rats with only one adrenal cortex). A dissociation between anti-t-PA and anti-u-PA response was seen in heart, liver and aorta. A variable change in PI was induced in kidneys, aorta, lungs and brain in all treatments except unilateral demedullation or unilateral adrenalectomy. Therefore, the effect of adrenalectomy or demedullation on tissue PAA, PAI and PI was variable and dependent on the extent of the treatment (unilateral or bilateral), the organ as well as the time after the treatment.

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 post-injection, while an increase of PAI (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 PAI (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.

Plasminogen activator activity (PAA), plasminogen activator inhibition (PAI) and plasmin inhibition (PI) have been studied with spectrophotometric methods in extracts of human, bovine, ovine and rat kidneys of both sexes. In all species studied, renal PAA (cortex or medulla) was higher in females than in males. The PAA was also higher in the medulla than in the cortex in all species and both sexes. The PAA was due to both types of plasminogen activator; tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA). In the human kidney (cortex or medulla) the measurement of t-PA antigen showed that t-PA is higher in females than in males; t-PA is also higher in the medulla than in the cortex in both sexes. The PAI showed the opposite pattern in all species studied; it was lower in females than in males. It was also lower in the medulla than in the cortex. PAI-1 was identified in the human kidney. Sex-related differences in renal PAA or PAI almost disappeared after bilateral orchidectomy in rats. PI showed no sex or regional differences in the species studied. Sex-related differences in renal PAA and PAI in man and various animal species might be of physiological or pathophysiological importance.