No abstract

Plasma progesterone (P(4)) concentrations are maintained in pregnant cats until parturition, but become low in pseudopregnant cats 40-45 days after infertile mating. This difference in P(4) concentrations is considered to be due to P(4) secretion by the placenta of pregnant cats. Therefore, to clarify these points, we performed ovariectomy (OVX) at various stages of pregnancy, examined the pregnancy status and measured LH and P(4) concentrations in peripheral, ovarian and uterine venous blood. After OVX, abortion occurred in 100% (5/5), 80% (4/5), 40% (2/5) and 60% (3/5) of Groups I (Day 35), II (Day 40), III (Day 45) and IV (Day 50) cats, respectively. In the remaining cats, normal delivery took place on days 63-69 [mean, 66.1 +/- 1.1 (SE)] of pregnancy. The time to abortion after OVX was 4-8 (mean, 5.6 +/- 0.8), 3-17 (mean, 8.0 +/- 3.6), 10 and 11, and 2-4 (mean, 3.0 +/- 0.7) days in Groups I, II, III and IV, respectively. The plasma P(4) concentrations were 1-2 ng/ml in all groups on the day after OVX, decreasing to less than 1 ng/ml from the 2nd day onwards. The concentrations of P(4) in ovarian venous blood at the time of OVX decreased with the stage of pregnancy, but were clearly higher than those in peripheral blood. The plasma P(4) concentrations in uterine venous blood were similar to those in peripheral blood. These results suggest that peripheral P(4) in pregnant cats is the result of P(4) secretion secreted only by the ovarian corpus luteum, not by the placenta, but indicate that either P(4) is not essential for the maintenance of pregnancy in cats from day 40-45 of pregnancy onwards, or that the placenta provides a local source of P(4) that does not appear in measurable amounts in the peripheral circulation.

We collected semen from a male Amur leopard cat using the transrectal electroejaculation method and investigated the semen qualities for about four years. In addition, the influence of the season on the spermatogenic function of the Amur leopard cat was investigated with regard to the semen qualities, testicular volume and serum testosterone level. As a result, we could collect semen with good sperm qualities that would be useable for artificial insemination. Some seasonality was noted in the testicular volume and serum testosterone level. We clarified that the semen qualities were favorable before and during the female breeding season compared with those after the breeding season.

ABSTRACT. Glycoproteins (GPs) are known to be involved in the phenomenon of sperm maturation and capacitation. In the present study, we investigated the attachment of GPs on sperm cell membrane during the process of feline sperm maturation from testicular sperm to ejaculated sperm by using 8 FITC-labeled lectins. The results showed that 3 types of GPs were presented on testicular sperm and 7 on caput epididymal sperm. Corpus and cauda epididymal sperm and ejaculated sperm had GPs detected by 8 FITC-labeled lectins used in the present study. This study demonstrates the part of the characteristic of GPs that are present on the feline sperm cell membrane during the process of sperm maturation.KEY WORDS: feline, glycoproteins, sperm.J. Vet. Med. Sci. 73(6): 827-829, 2011 Various glycoproteins (GPs) are present in epididymal secretions and secretions from the prostate gland, vesicular glands, and bulbourethral glands of mammals. Spermatozoa are sent from the testis to the efferent duct in an immature state [1,3,4,6,7]. The spermatozoa mature functionally during their transit through the epididymis, and they undergo capacitation and are stored in the cauda epididymis [2,3,5]. GPs that coat the surface of spermatozoa are acquired or lost and the characteristics of the GPs on the surface of the plasma membrane are changed during their transit through the epididymis [1-3]. There have been many reports on the relationships between sperm maturation, sperm capacitation, and decapacitation factors (DFs), and these have been investigated in many mammalian species [2,4,6,[9][10][11]. Kawakami et al. [6] used FITC-lectins to investigate GP adhesion to the surface of canine caudal epididymal sperm and ejaculated spermatozoa, and the results showed that PHA-E-lectin did not bind to caudal epididymal sperm, but did bind to ejaculated sperm. It was concluded that the saccharide N-acetyl-D-galactosamine to which PHA-E-lectin binds is a DF. Moreover, it has been reported GPs that bind to the PNA lectin have been observed during passage through the epididymis in the rat and pig [3,14], and that they are involved in sperm maturation and transport. In addition, the fact that lectin staining has been observed in the sperm of cattle and pigs after capacitation, and that WGA lectin binding was lost after capacitation has suggested that WGA-binding GPs are highly involved in the sperm capacitation phenomenon [3,4,11]. Thus, GPs appear to be involved in sperm maturation and capacitation.The only reports of research on feline sperm GPs thus far have been of studies in which FITC-lectins were used to determine whether an acrosome was present on the sperm head [8,13]. In the present study we investigated the attachment of GPs during the process of sperm maturation from testicular sperm to ejaculated sperm by using the 8 different FITC-lectins that are routinely used in this kind of study [3,4,6,7,9,11]. It can also be expected to identify groups that are in involved in sperm capacitation and DFs in the cat, the same as has been discussed in...

ABSTRACT. We observed the influences of low-temperature storage of the feline epididymis on the epididymal semen qualities before and after cryopreservation to identify the optimal duration for low-temperature storage of the epididymis. After excision, the feline epididymis was stored at 4  C for 0-72 hr and then subjected to epididymal sperm collection. When sperm from the refrigerated cauda epididymis were frozen and thawed, there was no significant difference in sperm motility between the 0-and 24-hr low-temperature storage groups, but sperm motility was significantly decreased in the 48-hr storage group. The above findings suggested that low-temperature storage of the epididymis until 24 hr is useful for frozen sperm collected from the feline cauda epididymis.KEY WORDS: cryopreservation, epididymal sperm, feline, refrigeration.J. Vet. Med. Sci. 72(6): 777-780, 2010 The total number of animals worldwide has decreased in many wildcat species, and various assisted reproductive technologies (ART) are necessary to maintain and increase their numbers. Many studies on ART for endangered feline species are underway using domestic cats as a model [1][2][3][4][5][10][11][12][13][14][15].In a previous study, we collected feline sperm from the cauda epididymis immediately after excision and performed intrauterine insemination of frozen semen (5  10 6 ) [14]. The mean sperm motility following freeze-thawing was 24.0  4.0% (SE), and the conception rate was only 27.3% (3/11). Two female cats delivered five and one kittens, respectively, and another one aborted on 30 days of gestation. This was our initial success rate achieved using epididymal frozen semen in cats. Our previous study is also the only one to report successful conception cases achieved using frozen feline epididymal semen thus far.The duration and temperature of storage before collection of sperm after excision of the epididymis have marked influences on semen qualities in various animal species [6][7][8][9]. In cats, Hay and Goodrowe [5] reported that semen qualities did not differ between sperm collected from the cauda epididymis immediately after excision and after 24-hr storage at 5C. Furthermore, Chatdarong et al. [3] compared the quality of caudal epididymal semen collect from the epididymis after storage for 2 and 4 days at 4C and reported that the sperm motility after storage for 2 days is significantly higher than that after storage for 4 days. Filliers et al. [4] observed that the qualities of semen from the feline epididymis stored in sterile physiological saline for 24 hr at 5C were good. However, Chatdarong et al. [3] and Filliers et al. [4] did not observe the semen quality immediately after excision. Tittarelli et al. [13] also stored the feline epididymis in sterile physiological saline or egg yolk-Tris for 24, 48 and 72 hr and observed the semen qualities. Sperm motility was apparently decreased at all storage time points, and egg yolk-Tris was suggested to be superior as a storage medium compared with physiological saline. Howev...

ABSTRACT. Cats show repeated copulation, but changes in semen qualities and quantities with repetition of ejaculation have not previously been clarified. We collected semen 4 times consecutively from 5 cats using the artificial vagina method and observed the semen qualities and quantities. No significant changes were noted in the semen volume, frequency of abnormal sperm or incidence of immature sperm, but the number of sperm and sperm motility and viability decreased with repetition, and in particular, the number of sperm in the first semen accounted for 55.0% of the total number in the 4 consecutive ejaculations, showing a significant difference from those in the 2nd-4th semen (P<0.01).KEY WORDS: consecutively ejaculation, feline, semen.J. Vet. Med. Sci. 73(2): 245-247, 2010 Cats are copulatory ovulators that show repeated copulation, but the ovulation induction rate per single copulation has been reported to be low by Concannon et al. [1], Wildt et al. [11], Glover et al. [4] and us [10]. Concannon et al. [1] observed the relationship between the number of copulations and plasma LH level after copulatory stimulation. Plasma LH elevation after a single copulation was insufficient to induce ovulation in some cats, and 50% (9/18) of cats in their experiment did not ovulate. However, the plasma LH level rose after copulation 4 times or more, and the ovulation induction rate reached 100% (36/36). Regarding the relationship between the number of copulations and conception, Glover et al. [4] reported that only one (25.0%) of 4 cats in which ovulation was induced by a single copulation was fertilized, but the conception rate was 71.4% (5/7) in cats that copulated 2-3 times. We also performed a similar experiment [10]; in that experiment, the conception rate was 37.5% (6/16) in cats in which ovulation was induced by a single copulation, but it increased to 94.1% (16/17) after 3 copulations, as reported by Glover et al. [4]. An insufficient number of sperm per copulation was assumed to be the reason for the low conception rate after a single copulation.However, changes in the qualities and quantities of consecutively ejaculated feline semen have not been clarified.Thus, we collected feline semen from 4 consecutive ejaculations using the artificial vagina method (AVM) and investigated changes in the semen qualities and quantities.Male cats bred and maintained in our colony were used in this experiment. Five 3.2-4.6-year-old cats weighing 4.2-5.3 kg were used. These cats showed normal copulatory capability and fertility. The animals were maintained in a room in which the temperature was adjusted to 23 2C and were kept individually in cages measuring 60  90  120 cm. The animal room was kept under a 12-hr lighting cycle. The animals were given commercial dry food (Hill's Feline Maintenance, Hill's Pets Nutrition, Inc., Topeka, KS, U.S.A.) and water ad libitum. The female estrous cats maintained in our colony were appropriately used for semen collection.This study was conducted in conformity with the animal study ...

ABSTRACT. It is thought that differences in conception rate between feline epididymal sperm and ejaculate sperm occur because, unlike ejaculated sperm, caudal epididymal sperm have not been sensitized with seminal plasma (SP). In this study, we investigated whether collection of feline epididymal sperm with SP influences sperm qualities after freezing-thawing. Sperm were sensitized with SP for 10 min at room temperature. As a result, the motility of caudal epididymal sperm sensitized with SP immediately after collection was significantly lower than that of ejaculate sperm, and no difference was noted in sperm qualities after freezing-thawing. This shows that the qualities of caudal epididymal sperm cannot be improved to a level higher than those of ejaculate sperm by sensitization with SP. KEY WORDS: epididymal sperm, feline, seminal plasma.doi: 10.1292/jvms.11-0175; J. Vet. Med. Sci. 74(10): 1349-1353, 2012 Since many wild feline species are on the verge of extinction, many researchers are investigating gamete preservation techniques [1,2,11,13,14,16]. We also previously reported on the acquisition of newborns by artificial insemination of frozen semen collected from the feline caudal epididymis using egg yolk Tris-fructose citrate (EYT-FC), but the conception rate was low [14]. However, regarding the qualities of semen used, sperm motility and viability were similar to those of feline frozen ejaculated semen used in artificial insemination as previously reported [15]. The lack of sensitization of epididymal sperm with seminal plasma (SP) was considered to be the cause of this difference. To investigate this difference, we observed glycoprotein attachment in epididymal sperm not sensitized with SP and sensitized ejaculated sperm using 8 types of lectin [12]. However, no difference was noted in lectin binding between feline epididymal and ejaculated sperm. The effects of SP on sperm functions have been reported to be positive or negative in various animal species [3,4,[6][7][8]11].Kawakami et al.[5] investigated protein attachment on the surfaces of canine caudal epididymal and ejaculated sperm. They observed that PHA-E lectin did not bind to caudal epididymal sperm but bound to ejaculated sperm and suggested that a PHA-E lectin-binding glycoprotein, N-acetyl-D-galactosamine, is a decapacitation factor. Hori et al. [4] collected canine caudal epididymal sperm using SP and found that sperm qualities after freezing-thawing were apparently superior to those of ejaculated semen and that the conception rate after intrauterine artificial insemination was apparently higher. However, they did not clarify the reason why epididymal sperm collected with SP was superior to ejaculated sperm.In this study, we investigated whether collection of feline epididymal sperm with SP improves sperm qualities after freezing-thawing.Epididymal sperm from 5 male mixed domestic cats of known age that had been brought to an animal hospital for castration were used in this study. The cats ranged in age from 2.0 to 7.0 years old (3.2 ± 0.6 (...

ABSTRACT. On the assumption that animals of wild feline species died in the field, caudal epididymal sperm were cryopreserved following storage of the feline epididymides at 20C for 0-24 hr, and their qualities were observed. Compared to the qualities at 0 hr, no significant differences were noted following 12 hr of storage at 20C. On comparison of the qualities between caudal sperm cryopreserved after 24 hr storage at 4C and after 12 hr at 20C followed by 12 hr storage at 4C, no significant differences were noted. These findings suggest that the cryopreserved sperm collected from epididymides of dead animals might be useful for artificial insemination if cryopreservation was performed within 12 hr exposure to ambient temperature.KEY WORDS: epididymal sperm, feline, frozen semen.J. Vet. Med. Sci. 73(10): 1395-1398, 2011 Most wild animals are currently in danger of extinction, with the highest percentage of endangered species being in found in the order Carnivora and the family felidae [1]; and much research on how to maintain species of endangered felidae has been conducted in consideration of the fact that they are often killed in accidents or as a result of poaching [4][5][6][7][8]. The domestic cat has often been used as a model in such studies. The domestic cat has also been used to conduct research on the quality of sperm from each part of the epididymis and on methods of preservation [5][6][7] and methods of artificial insemination (AI) [8,9] with cryopreserved sperm from caudal epididymides, among others. The authors have reported on changes in sperm quality when feline epididymides were stored at low temperature (4C) [7], and on the conception results after intrauterine AI and intratubal AI with cryopreserved sperm from epididymides were stored at low temperatures [8]. The authors' research thus far has been conducted on the assumption that it is possible to excise the epididymides immediately after the death of wild felidae. However, when felidae die in the wild, it may not be possible to excise the epididymides immediately and transport then to a laboratory. Sperm quality may deteriorate when they are left at ambient temperature for a prolonged period. Therefore, it also appears important to plan experiments based on the assumption that an animal's carcass might remain exposed outdoors after death. There are reports on this problem in the case of dogs [2] and deer [1], but so far there have been no reports about cats.In the present study we therefore collected sperm from epididymides that had been stored at room temperature (20C) for various lengths of time, and examined sperm quality after thawing. We also examined epididymides at low temperature (4C) after storage at room temperature (20C), and then cryopreserved the caudal epididymal sperm. The cryopreserved sperm was prepared on the assumption that it would be used for AI.Twenty male mixed domestic cats (Felis catus) of known age brought to an animal hospital for castration were used in this study. The cats ranged in age from 1.0 to 8.0 ye...