Although mice kidney morphology shows various sexual dimorphisms, the effect of the estrous cycle has not previously been discussed. In this study, we investigated the effects of the estrous cycle on kidney morphology, including renin-positive areas, of female DBA/2 mice. No effects were confirmed in most of the histometrical parameters, however, the percentage of the renal corpuscles in which cuboidal epithelium covered under 50% of the parietal layer was significantly higher during estrus compared to that during anestrus.
Since certain characters of allergic asthma are common with other allergic disorders like atopic dermatitis, the possible relationship in etiology is expected. Herein, we investigated whether NC/Nga mice, an inherent animal model for human atopic dermatitis, are inclined to allergic asthma. A single intranasal challenge of NC/Nga mice immunized with ovalbumin (OVA) resulted in an increase in plasma levels of OVA-specific IgE, and typical pathological aspects of allergic asthma characterized by infiltration of numerous eosinophils, mucus hyper production of bronchial epithelial cells. Moreover, airway hyperresponsiveness to inhaled acetylcholine and marked enhancement of airway resistance after the challenge were observed as compared to control BALB/c mice. Delayed expression of mRNA of eosinophil active chemokines, interleukin-5, eotaxin, macrophage inflammatory protein-1 α in concert with eosinophilia was determined in the lung of NC/Nga mice. These results suggest that asthmatic responses developed in NC/Nga mice challenged with OVA are very similar to human allergic asthma, and that NC/Nga mice are a useful model to elucidate various aspects of allergic asthma.
In previous study, NC/Nga mice with experimentally induced asthma showed severe eosinophilia. To explore the mechanism, profiles of representative cytokines interleukin (IL)-4, IL-5, and interferon (IFN)-γ were examined in bronchoalveolar lavage fluid. The level of only IFN-γ was lower in NC/Nga mice than control BALB/c mice. Furthermore, bone marrow cell culture system under the presence of eosinopoietic cytokines, which induce the differentiation of progenitor cells into mature eosinophils, showed that a larger number of eosinophils differentiated from NC/Nga mice derived bone marrow cells than from control BALB/c mice. These results may imply the possibility that severe eosinophilia in the NC/Nga mice are attributable to lower production of IFN-γ and higher eosinophil productivity of bone marrow cells.
The effect of low dose dopamine on the excretory urographic image quality and contrast media-induced nephropathy in normal dogs (experiment 1) and the dogs with decreased renal function (experiment 2) were assessed. In experiment 2, decreased renal function was induced by gentamicin overdose. In each experiment, animals were divided into 3 groups. In group 1, only contrast medium (iohexol) was administered. In group 2, contrast medium plus intravenous fluid (0.9% saline) were administered. And in group 3, contrast medium plus intravenous fluid and low dose dopamine were administered. Investigated parameters included intrarenal resistive index (RI), serum BUN and creatinine concentrations, contrast medium elimination time and radiographic image quality. In experiment 1, RI of group 1 increased at 80 min after contrast medium administration (p<0.05), but RI of group 3 decreased at 48 and 72 hr (p<0.05). Serum BUN concentration of group 1 was higher than that of group 2 and 3 (p<0.05); in radiographic examination, contrast medium elimination time decreased in group 2 and 3, but image quality of group 2 was inferior to that of group 3. In experiment 2, image quality of group 3 only provided adequate visualization of renal structures. The formula of contrast medium plus low dose dopamine was found to provide good nephrogram and pyelogram image quality without supplemental contrast medium, and to protect renal tubules from prolonged exposure to concentrated contrast medium.
To clarify the influence of rearing conditions on the growth of various body parts of Japanese macaques (Macaca fuscata), two groups reared under different conditions, i.e., a group born and reared in open enclosures (Enclosure group) and another consisting of macaques born and reared in cages (Caged group), were somatometrically analyzed. Somatometric data on 36 measures of various body parts were collected from 77 males and 92 females. Growth in many body parts was smaller in the Caged group than in the Enclosure group. Body parts that exhibited large incremental increases were more sensitive to differences in rearing space at the infantile growth stage in both sexes. Recovery from delayed growth at the pubertal growth stage was found in many body parts. However, the size of some locomotor elements such as the wrist and hand, and ankle and foot strongly reflected limitations of space and changes due to this were irreversible. Females were more sensitive than males to such differences in rearing conditions. We conclude that open enclosures with ample rearing space are necessary for the innate growth of Japanese macaques to occur.
Microsatellite polymorphism due to differences in CT dinucleotide repeats was demonstrated in intron 14 of the canine BRCA1 gene. Genotype analysis of 103 unrelated dogs from 30 different breeds detected the presence of five alleles, including 10 of the expected 15 genotypes. Gene frequencies were biased and all alleles with the exception of one were below 0.1. This polymorphism, which occurs at the intron of canine BRCA1 should prove to be a useful marker for detecting the loss of heterozygosity (LOH). One of the more notable findings of the present study was the detection of homozygotes of rare alleles. This finding identified an accumulation of rare alleles in specific canine breeds and demonstrated the usefulness of this characteristic for the biological study of dog evolution.
The main complications of clonorchiasis are periportal inflammation, biliary hyperplasia, periductal fibrosis, and subsequently the development of biliary tumors in the liver. This study was undertaken to compare the infectivity and histopathologic changes between in immunocompetent FVB/NJ and BALB/cA strains, and immunodeficient severe combined immunodeficient (SCID) and athymic nude mice after the metacercariae of Clonorchis (C.) sinensis were infected. The experiment showed that C. sinensis was very infective in all strains studies, but the status of worm development, infectivity, recovery rate, and morphological changes of livers were very different in each strain. FVB/NJ mice showed more worm recovery than any other strain. Histopathologically the liver of FVB/NJ mice at 4 weeks postinfection showed marked cystic and fibrotic changes, in which C. sinensis was fully developed with ovum production, severe infiltration of inflammatory cells, mostly eosinophils, and high degrees of biliary hyperplasia. In SCID and nude mice, there were few foci of inflammatory cells even at 8 weeks postinfection in periportal areas of the liver, associated with no development into adult worm with ovum production. Fibrosis occurring at 4 weeks postinfection was highly correlated with inflammatory infiltration when each strain was compared. We suggest that massive infiltration of eosinophil and plasma cells caused by the infection might initiate cystic formation and fibrosis. These data demonstrate that the infection of C. sinensis might be related to pathologic consequences of inflammatory cell infiltration, cystic formation and fibrosis which might play a role in the defense mechanism against the parasitism in the liver of each strain. The FVB/NJ mouse model might be very helpful in elucidating the mechanism for human clonorchiasis.
Numerous studies have supported the importance of immunity to SAG1, the most predominant antigen of Toxoplasma tachyzoite, in protection against Toxoplasma gondii infection. Nevertheless, vaccination with SAG1 provides insufficient protection when compared with that of Toxoplasma lysate (TL). In order to screen the Toxoplasma antigens for immunogenic potential shown by modified protection or induction of specific immune response after infection, recombinant antigens were prepared in Eschericha coli using DNA fragments corresponding to SAG1, SAG2, SAG3, SRS1 and P54 of T. gondii RH strain maintained in our laboratory. Each of the recombinant antigen products or a mixture of the five antigens (Mix) was used to vaccinate mice. Mice then received a lethal dose of T. gondii. Up to 25% of the mice vaccinated with SAG2, SRS1, P54 and Mix survived, whereas there were no survivors in gene 10- (negative control), SAG1- and SAG3-vaccinated groups. In all the survivors, brain cysts were not observed. Conversely, vaccination with TL almost completely protected mice in the acute phase but permitted brain cyst formation and resulted in gradual decrease of survivors to 33% during 4 months of experiments. Western blot analysis on convalescent sera showed an extensive IgG induction to a 30 kDa antigen in TL-vaccinated mice, a 22 kDa in SAG2-vaccinated mice and a 55 kDa in P54-vaccinated mice. The protection modified by boost in specific antibody is suggestive of the immunogenic potential of SAG2, SRS1 and possibly P54 against T. gondii infection.
The growth inhibitory effects of recombinant canine interferon alpha (IFN-α), beta (IFN-β) and gamma (IFN-γ) were examined on Madin-Darby canine kidney cells infected with Neospora caninum tachyzoites. The parasite growth was inhibited by all IFNs in a dose-dependent manner. IFN-γ inhibited the parasite growth with greater efficacy than IFN-α or IFN-β. Moreover, the effect of IFNs on N. caninum growth associated with the suppression of the host cell viability. The present study indicates IFN-a and -β, besides IFN-γ, play a crucial role for N. caninum growth in host cells.
Parasitological and histopathological examinations were performed in 25 raccoon dogs (Nyctereutes procyonoides) obtained in Kanagawa Prefecture, Japan, all of which were found to be heavily infected with Sarcoptes scabiei. The mites detected on these raccoon dogs were morphologically indistinguishable from the human species, and no Demodex mites were detected. Histopathological examinations showed prominent hyperkeratosis and acanthosis with eczema, and numerous burrows containing mites were observed in the epidermis. The enzootic dermatitis of wild raccoon dogs in recent years was clearly demonstrated to be caused by S. scabiei in the present study.
The histological characteristics of 9 cases of granular cell tumors (GCTs) observed in B6C3F1 mice were examined to determine their cellular origin. Seven of the 9 cases were found in the uterus and other 2 cases were in the subcutaneous tissue. Tumor cells had abundant granules in the cytoplasm which were stained with PAS and were resistant to diastase treatment. Ultrastructurally, the granules were identified as lysosomes. The cell surface had cytoplasmic processus showing interdigitation with adjacent cells. A character feature of the tumor cells was the presence of a desmosome-like structure on their cell surface but no basal lamina was demonstrated. Although GCTs have been considered to be derived from Schwann cells on the basis of their ultrastructural features and S-100 protein-immunopositive findings, the absence of basal lamina in the present cases may raise a controversy as to their origin.
A transitional type of combined hepatocellular and cholangiocellular carcinoma developed in a 12-year-old male Yorkshire terrier dog. The tumor was histologically composed of both hepatocellular carcinoma and cholangiocellular carcinoma components, and both elements were closely intermingled. Intraluminal mucin accumulation in cytokeratin-positive tubular/glandular structures was observed within the cholangiocellular carcinoma components and this feature was useful histological marker for a differential diagnosis between combined hepatocellular and cholangiocellular carcinoma and a pseudoglandular type of hepatocellular carcinoma. This primary hepatic tumor is extremely rare in dogs.
The amounts and time courses of dopamine and ATP released from perfused PC12 cells were examined using a simultaneous on-line recording system. High KCl (60 mM) caused dopamine and ATP release with similar time courses. The relative amount of dopamine to ATP in the effluent was 9.5. In PC12 cells cultured with dexamethasone, reserpine or bafilomycin A1 for 2 days, these drugs did not affect increases of intracellular Ca2+ in response to high KCl. Dexamethasone doubled the amount of dopamine release induced by high KCl without changing the amount of ATP release. High KCl failed to cause dopamine release in reserpine-treated cells but evoked ATP release. Bafilomycin A1 decreased both high KCl-induced dopamine and ATP release. The ratio of released ATP to total adenine nucleotides and adenosine in response to high KCl was not changed by treatment with the drugs. These results suggest that dopamine and ATP are simultaneously released from secretory vesicles of PC12 cells, in which they are stored via different pathways. Similar to dopamine uptake into secretory vesicles, the H+-gradient across the vesicular membrane developed by vacuolar ATPase may play an important role in the vesicular uptake of ATP.
The mechanism of carbon monoxide (CO)-induced relaxation were investigated in the guinea-pig ileum. CO (10%) inhibited the 40 mM KCl-induced contraction. This effect was antagonized by ODQ (1 μM), a soluble guanylate cyclase inhibitor. In contrast, CO did not inhibit the 40 mM KCl-induced increase in cytosolic Ca2+ level ([Ca2+]i). Cumulative addition of KCl induced a graded increase in both [Ca 2+]i and muscle tension. In the presence of CO, the increase in muscle tension was attenuated whereas the increase in [Ca2+]i was only slightly decreased. Thus, the [Ca2+]i-tension relationship constructed by cumulative addition of KCl shifted downwards in the presence of CO. Using the patch clamp, CO was found to have little effect on the peak Ba currents (IBa) when voltage was stepped from -60 mV to 0 mV. From these results, we conclude that CO inhibits contraction of guinea-pig ileum mainly by the decrease in the sensitivity of contractile elements to Ca2+ via a cyclic GMP-dependent pathway but not by the inhibition of L-type Ca2+ channel.
Lysophosphatidylcholine (LPC), which exists abundantly in lipid fraction of oxidized low density lipoprotein, has been implicated in enhanced agonist-induced contraction and increase of intracellular Ca2+. The effect of LPC on the activity of delayed rectifier K+ current (IdK), which is a major determinant of membrane potential and vascular tone under resting condition, was examined in rabbit coronary smooth muscle cells using whole cell patch clamping technique. Application of LPC to the bath solution caused a concentration-dependent inhibition of IdK, and the concentration to produce half-maximal inhibition was 1.51 μM. This effect of LPC on IdK was readily reversed after washout of LPC in the bath. The steady-state voltage dependence of IdK was shifted to positive direction by both extra- and intracellular application of LPC. Staurosporine (100 nM) pretreatment significantly suppressed the LPC-induced inhibition of IdK. These results suggest that LPC inhibits IdK in rabbit coronary smooth muscle cells by a pathway that involves protein kinase C, and the LPC-induced inhibition of IdK may be, at least in part, responsible for the abnormal vascular reactivity in atherosclerotic coronary artery.
Serum IL-1β, IL-6 and TNFα were not detected in control and Mg-deficient rats. These three cytokine levels in serum were increased after endotoxin challenge (1 mg/kg., i.p.), and the increase of IL-1β and IL-6, but not TNF α, was significantly larger in Mg-deficient rats than in controls. Levels of mRNA for IL-1β, IL-6 and TNFα in alveolar macrophages showed a tendency to decrease during Mg deficiency, but the levels of IL-1β and TNFα mRNAs after endotoxin challenge were higher in Mg-deficient rats than in controls. These results suggest that the increased synthesis of cytokines by alveolar macrophages might contribute, in part, to high sensitivity to endotoxin during Mg deficiency.
Cardiopulmonary reflexes elicited by capsaicin (CAPS) instilled into the nasal passages were determined in 6 anesthetized dogs breathing spontaneously. Nasal instillation of CAPS (10 μg/m l, 10 ml) induced: 1) apneic response characterized by an increase in expiration time; 2) bronchoconstrictor response characterized by an increase in lung resistance and a decrease in dynamic compliance; and 3) cardiovascular response characterized by a decrease in heart rate and an increase in arterial blood pressure. These reflex responses to CAPS were attenuated by pretreatment with a higher dose of CAPS (100 μg/ml, 10 ml), suggesting desensitization of CAPS-sensitive endings. These results suggest that marked cardiopulmonary reflexes are produced by nasal CAPS instillation, which may result, at least in part, from stimulation of nasal CAPS-sensitive sensory afferents.
In dogs, embryo transfer (ET) techniques such as induciton of excessive ovulation and synchronization of estrus have not progressed well. Therefore, using embryos at various developmental stages, ET was investigated in dogs from a beagle colony in which the ovulation days were close, as estimated by the progesterone level. Embryos were recovered 8-11 days after ovulation (4-9 days after mating) by excising the oviducts and uteri (excision method) in 16 animals and by surgical flushing of the uteri at laparotomy (surgical method) in 3 animals. In 24 dogs with -4 to +2 days of difference in the timing of ovulation between donor and recipient dogs, 1-10 embryos at the 8-cell to blastocyst stages were transferred per animal. The mean embryo recovery rate by the excision method (97.1%) was significantly higher than that by the surgical method (42.5%) (p<0.01). Twelve (57.1%) of 21 animals with -1 to +2 days difference in ovulation day became pregnant after the transfer of 8-cell to blastocyst stage embryos. Although 3 dogs with -4 to -2 days of difference of ovulation day underwent ET of morula or compacted morula, none of these dogs became pregnant. The mean ratio of the number of newborns to the number of transferred embryos was only 51.9%. The mean duration of the period between ovulation and delivery in the pregnant recipients was 65.8 days, which tended to be longer than that in natural mating. These results demonstrate that pregnancy can be induced by ET at the 8-cell to blastocyst stage in dogs with -1 to +2 days difference in ovulation day.
The semen quality of 22 dogs (4 to 7 years old) with benign prostatic hyperplasia (BPH) was examined at the hospital of our university, and 4 of the 22 BPH dogs were diagnosed as azoospermic. The mean peripheral plasma estradiol-17β (E2) level (17.3 pg/ml) of the 18 BPH dogs with spermatogenic function was higher than that of 5 normal male dogs and their mean T level (1.7 ng/ml) was lower. The mean E2 level (27.3 pg/ml) of the 4 BPH dogs with azoospermia was significantly higher than the value in the BPH dogs with spermatogenic function (P<0.01), and the mean T level (1.1 ng/ml) was significantly lower (P<0.05). Five normal male dogs were given 10 intramuscular injections of estradiol benzoate (E2B) 5 μg/kg, at 3-day intervals to investigate the relationship between high plasma E2 levels and the cause of the BPH and azoospermia. Their testes and prostates were measured and biopsied both before and 30 days after the start of E2B injections. At 30 days after the start of the E2B injections, the mean peripheral plasma T levels had decreased by half, and the mean testicular volume had decreased to 88% of original volume. The numbers of spermatocytes, spermatids, and spermatozoa in the seminiferous tubules of all of the dogs were significantly lower (P<0.05, 0.01). In addition, the mean prostatic volume increased to 130%, the mean height of the glandular epithelium decreased, and the glandular lumen became increased in diameter. These findings indicate that both BPH and serious spermatogenic dysfunction may be simultaneously induced by protracted high plasma E2 levels in dogs.
The effects of osaterone acetate (OSA), which is an anti-androgen agent being developed as a therapeutic drug for benign prostatic hypertrophy (BPH) in dogs, on the degree of prostatic regression and semen qualities were investigated. Prostatic regression was compared between dogs with and without orchidectomy. Five male beagles aged 5-9 years were used in the experiment. OSA was orally administered at doses of 0.2 mg/kg and 0.5 mg/kg for one week. The prostatic regression rate one week after the end of administration was 62.6% on average. In the orchidectomized group, the mean regression rate one week after orchidectomy was 60.1%. However, the prostate became enlarged 6 months after administration, compared to the size prior to administration. The above findings suggested that OSA is clinically applicable as a therapeutic drug for BPH in dogs, and inhibits prostatic hypertrophy during the early phase.
A 38-month-old female Golden retriever was presented with dysuria and dyschezia. It was difficult to visualize the vagina by vaginoscopy due to a cystic polyp on the hymen. The polyp was 2 × 3 cm in diameter, round, and pink in color. From clinical and imaging evaluations the original diagnosis was mucometra or pyometra. From endoscopic examination of the vagina an imperforate hymen was finally diagnosed. The ovaries, uterus, and half of the vagina were removed through a median abdominal incision. The vagina contained about 1.5 liters of fluid, but the uterus and ovaries appeared normal. This is a rare case with imperforate hymen and hydrocolpos with a polyp on the hymenal membrane in bitch.
2-Bromopropane (2-BP) causes testicular toxicity in humans and rats. However, the germ cell degeneration of testicular toxicity by 2-BP has not been understood. 2-BP at doses of 135, 405, and 1,355 mg/kg/day was daily injected subcutaneously into Sprague-Dawley rats for 28 days. At the dose of 1,355 mg/kg/day, 2-BP significantly decreased the weights of body and testes, eipididymis, seminal vesicle, and prostate, as well as daily sperm production. Atrophy of seminiferous tubules accompanied with degeneration of germ cells such as spermatogonia, spermatocytes, and elongated spermatids was observed in the testes of rats exposed to the 405 mg/kg/day and 1,355 mg/kg/day of 2-BP. TUNEL-positive germ cells were appeared in the 405 and 1,355 mg/kg/day of 2-BP-treated groups. In addition, ultrastructure alterations of apoptotic germ cells were observed by the electron microscopy study. Dead elongated spermatids were observed at 1,355 mg/kg/day after 28 days exposure. These results suggest that 2-BP impair spermatogenesis may result from apoptotic germ cell death.
The mechanisms of Marek's disease virus (MDV) entry to host cells have not yet been analyzed. Heparan sulfate (HS) on the cell surface serves as a receptor for several herpesviruses in mammalian species. In this study, we demonstrated that plaque formation by cell-free MDV is inhibited by the addition of soluble heparin to the cell culture. Moreover, pretreatment of susceptible cells, chicken embryo fibroblasts, with heparinase, partially reduced infectivity of the cell-free MDV. From these results, it was suggested that the MDV entry, at least in the case of cell-free MDV, is dependent on the presence of cell surface glycosaminoglycans, principally HS.