Effects of administration of prostagrandin F(2)(alpha)-analogue fenprostalene on canine corpus luteum and subsequent recurrence of estrus and fecundity

The effects of the long-acting prostagrandin F(2)(alpha)-analogue fenprostalene were investigated. Twenty-three female beagles (24 cases) 1-6 years of age were divided into 6 groups, and a dose of 5-150 microg/head of fenprostalene was subcutaneously administered at 25 days after ovulation to investigate its effects based on peripheral blood progesterone (P(4)) levels. The dogs were also examined for shortening of their estrous cycle after administration and fecundity after the recurrence of estrus. The results showed that the administration of 50 microg/head of fenprostalene or more reduced the levels of peripheral blood P(4) to about 1 ng/ml 2 days after administration, indicating early regression of the corpus luteum, and that the administration of these doses shortened the time to the subsequent estrus by a mean of about 80 days, and that conception rates were normal if estrus recurred about 2 months after fenprostalene administration or later.     

Influence of a PGF2alpha-analogue, etiproston tromethamine, on the functional corpus luteum of dogs

To induce luteal regression-related abortion/delivery and treat pyometra in dogs, various PGF2alpha-analogues (PGAs) are administered, but a PGA most appropriate for clinical application in dogs, with a low incidence of side effects, is being investigated. In this study, we compared the effects of etiproston tromethamine (PGA-E), which has not been investigated in dogs, with those of cloprostenol (PGA-C), which is routinely used in dogs. A single dose of PGA-E at 100, 200, 400 or 800 microg or PGA-C at 12.5, 25, 50 or 100 microg was administered to beagles (n=5 per group) 25 days after ovulation, when the corpus luteum was in the functional phase. We compared the state of luteal regression by measuring plasma progesterone levels. As side effects, the incidences of salivation, vomiting, tachypnea, diarrhea and the drop in body temperature were investigated. In the 400-microg and 800-microg groups treated with PGA-E, the mean intervals from administration until luteal regression were 18.6 days and 31.2 days, respectively. In the dogs treated with 50 microg or more of PGA-C, luteal regression was noted 2 days after administration. The above side effects were observed for 3 hr after administration of PGA-E/PGA-C. In the dogs treated with 800 microg of PGA-E, the mean body temperature was 36.7 degrees C 4 hr after administration; hypothermia persisted. PGA-E may be less useful than PGA-C for promoting luteal regression in dogs in clinical application.     

Disappearance of the PHA-E lectin binding site on the surface of ejaculated sperm and sperm capacitation in the dog

Ejaculated semen and cross sections of the cauda epididymides collected from 3 normal dogs were smeared or stamped on glass slides, and the sperm on the slides were stained with 7 different FITC-lectins (Con A, DBA, GS-1, PHA-E, PSA, UEA-1, WGA) to examine the relation between sperm-binding glycoprotein derived from the canine prostate and sperm capacitation. The only lectin that stained the ejaculated sperm but not the cauda epididymal sperm was PHA-E. The sperm ejaculated by 5 other dogs were incubated for 4 hr in fluid flushed from the uterine horns or oviducts of estrous bitches, and then the percentages of actively motile sperm and hyperactivated sperm (HA-sperm) were determined. The percentages of PHA-E-labeled sperm and sperm labeled with fluoresceinated Ca indicator to assess the influx of Ca into the sperm were also evaluated. The mean percentages of actively motile sperm, HA-sperm, and Ca-labeled sperm after 4 hr of incubation in the uterine flush fluid and oviductal flush fluid were significantly higher than in control medium (P<0.05, 0.01), but the mean percentages of PHA-E-labeled sperm were lower (both P<0.01). The percentages of PHA-E-unlabeled sperm correlated with the percentages of both HA-sperm and Ca-labeled sperm (r(2)=0.787 and 0.812, respectively). The results indicate that loss of the glycoprotein secreted by the canine prostate on the sperm surface induces the influx of Ca into the sperm, and then hyperactivation of the sperm.     

Mixed Type of Malignant Mesothelioma in an Aged Male ICR Mouse

Multiple whitish nodules in the thoracic cavity at the site of the thymus were observed in a 101-week-old male ICR mouse. In a histopathological examination, the neoplastic cells were predominantly fusiform in shape and proliferated in sarcomatoid growth patterns. Some neoplastic cells showed epithelial growth patterns, such as the ductal structures. Mitotic figures were frequently seen, and small necrotic foci and invasion to adjacent thoracic organs were noted. In Alcian blue staining, bluish materials were observed between fusiform-shaped cells and in some of the lumens of the ductal structures. In immunohistochemistry, both fusiform-shaped and ductal structure-forming cells were positive for vimentin and weakly positive to positive for cytokeratin. Based on the aforementioned findings, the thoracic nodules were diagnosed as a mixed type of malignant mesothelioma. This case was thought to be rare because of the very low occurrence of spontaneous mesothelioma in mice.     

Immunolocalization of von Willebrand factor and vascular endothelial growth factor during follicular atresia in the swamp buffalo ovary

The aim of this study was to investigate the distribution pattern of von Willebrand factor (vWF) and vascular endothelial growth factor (VEGF) in the healthy antral and atretic follicles of Philippine swamp buffaloes (SB) in comparison with Holstein-Friesian cows (HF). Paraffin sections of healthy follicles and atretic follicles at various stages were immunostained with vWF antibody and VEGF antibody. The density of vWF-positive capillary vessels in the theca interna significantly increased as atresia progressed in SB, whereas the density significantly decreased in late atretic follicles compared with advanced ones in HF. On the other hand, the area of vWF-positive capillary vessels in the theca interna significantly increased as atresia progressed in both SB and HF. Immunoreactions of VEGF in the granulosa cells (in all follicle types) were observed in both SB and HF. In the granulosa layer, a reduction in the VEGF immunoreaction was noted as follicles progressed from healthy to advanced atretic follicles in both animals. Granulosa cells (in both SB and HF) showed a higher immunopositive staining than theca cells. In the theca interna, VEGF immunostaining diminished as follicles progressed to the late atretic follicles in both animals. These results indicate that during atresia, changes of vWF expression are the opposite of VEGF expression in SB. Both vWF and VEGF are suggested to be associated with follicular atresia in SB.     

Breeding season in female cats acclimated under a natural photoperiod and interval until puberty

The breeding season was investigated in 174 female cats that were acclimated under a natural photoperiod, and determined the interval between birth and initial estrus (puberty) was determined in 125 cats. Although the breeding season differed noticeably among individual animals, the mean was 180.4 +/- 3.0 (SE) days between the end of January and the end of July. The interval between birth and first estrus ranged from 181 to 560 days, with a mean of 345.0 +/- 0.9 days. With respect to month of birth, the mean interval was 343.0 +/- 9.5 days in cats born between March and June. Among cats that were born between July and October, the mean intervals were 242.0 +/- 6.3 days in cats that exhibited estrus the year after birth and 519.2 +/- 5.8 days in those that exhibited estrus 2 years after birth.     

Treatment of prostatic abscesses by aspiration of the purulent matter and injection of tea tree oil into the cavities in dogs

Ultrasonography-guided transabdominal needle aspiration was carried out to remove 3 to 14 ml of purulent matter from the cavities of prostatic abscesses in 6 dogs, and the same volume of tea tree oil was injected into the cavities to treat the abscesses. The same treatment was repeated 3 weeks later in 4 dogs, and subsequent disappearance of the purulent matter in the cavities and a marked reduction in the volume of the cavities were observed. These findings indicate that the treatment of prostatic abscesses by aspiration of the purulent matter and injection of tea tree oil into the cavities is very effective in dogs.     

Estimation of potential area of preparatory irrigation for rainy season lowland rice and supplemental irrigation for dry season cropping using existing reservoirs constructed for aquaculture: a case study in semi-mountainous village,Lao PDR

Paddy and Water Environment - The rural area in Lao PDR has a low yield of rainy season lowland rice, and most rice fields are not utilized for crop cultivation during the dry season. Delay in...     

Changes in plasma testosterone levels and semen quality after 3 injections of a GnRH analogue in 3 dogs with spermatogenic dysfunction

Three male Beagles with low plasma luteinizing hormone and testosterone levels and spermatogenic dysfunction (SD-dogs) were given 3 weekly subcutaneous injections of a gonadotropin-releasing hormone analogue (Buserelin; GnRH-AB). The plasma T level of all of the SD-dogs increased and peaked at 4-6 weeks after the first injection. The total number of sperm and the sperm motility of the three SD-dogs increased 5-7 weeks after the first injection. Therefore, the authors concluded that 3 weekly injections of GnRH-AB transiently improves semen quality in some cases of canine spermatogenic dysfunction.     

Changes in the thecal vasculature during follicular atresia in the ovary of swamp buffalo

This study aimed to describe the changes in the thecal vasculature during ovarian follicular atresia in the swamp buffalo. Ovaries of Philippine swamp buffalo (Bubalus bubalis; SB), crossbred (SB x Murrah buffalo; CB) and Holstein-Friesian cow (Bos taurus; HF) were collected from slaughterhouses, fixed in 10% formalin in PBS and embedded in paraffin. Sections of healthy follicle and various follicular stages of atresia were stained with Bandeiraea simplicifolia-I lectin (BSL-I) to visualize the endothelial cells of blood vessels. In the theca interna, healthy follicles in SB had a significantly lower number of capillary vessels than other breeds and other atretic stages of follicle. From healthy to early atretic follicle, theca interna in all breeds showed a significant decrease in the area of capillary vessel. Capillary vessel area significantly increased (but was smaller than in healthy follicle) in the middle stage of atresia and declined again in the late atretic follicle (greater than in early atresia but smaller than in healthy follicle) in SB only. No significant change in the capillary vessel area of theca interna was noted in both CB and HF from early to late atretic follicles. There was no significant difference in the capillary vessel number and area of theca externa among the different breeds and atretic stages of follicle. These results suggest that there are dynamic changes occurring in the thecal vasculature of SB but not CB during follicular atresia which differs among cattle.