首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
To investigate the efficacy of voriconazole for the treatment of aspergillosis, three groups of six racing pigeons (Columba livia domestica) were inoculated in the apical part of the right lung with 2 × 107 conidia of an avian derived Aspergillus fumigatus strain. The minimal inhibitory concentration of voriconazole for this strain was 0.25 μg/ml. In two groups, voriconazole treatment was started upon appearance of the first clinical signs and continued for fourteen days. The third group was sham treated. The voriconazole-treated pigeons received voriconazole orally at a dose of 10 mg/kg body weight (BW) q12h (group 1) or 20 mg/kg BW q24h (group 2). Sixteen days post-inoculation all surviving pigeons were euthanized. Weight loss, clinical scores, daily mortality, lesions at necropsy and isolation of A. fumigatus were compared between all groups. In both voriconazole-treated groups, a significant reduction in clinical signs and lesions was observed. Administering voriconazole at 10 mg/kg BW q12h eliminated A. fumigatus and administering voriconazole at 20 mg/kg BW q24h reduced A. fumigatus isolation rates. Mild histological liver abnormalities were found in group 1 (10 mg/kg BW q12h), while mild histological as well as macroscopic liver abnormalities were found in group 2 (20 mg/kg BW q24h).In conclusion, voriconazole at 10 mg/kg BW q12h in pigeons reduces clinical signs and eliminates A. fumigatus in racing pigeons experimentally infected with A. fumigatus.  相似文献   

2.
Gastric Helicobacter spp. are associated with chronic inflammation and neoplastic transformation in humans as well as domestic and laboratory species. The present study examined the association of Helicobacter heilmannii (Hhe) infection in pet cats with feline gastric mucosa associated lymphoid tissue (MALT) lymphoma. Tissues were collected via gastric biopsy or at necropsy from 47 pet cats with clinical signs of gastrointestinal disease, including vomiting and inappetance, and classified as gastritis (14/47), lymphoma (31/37), or normal (2/47). Tissues positive for argyrophilic organisms with Warthin–Starry stain (29/47) were assessed by fluorescent in situ hybridization (FISH) for the presence of Hhe strains 1–4 as well as with a fifth probe that detected Helicobacter salomonis, Helicobacter bizzozeronii, or Helicobacter felis. A significant association of positive Warthin–Starry status with Hhe infection was found in cases of sick cats (22/29; p < 0.05 by Chi-square; χ2 = 7.034). Interestingly, a significant association between Hhe status and a diagnosis of lymphoblastic or lymphocytic lymphoma was observed as well in a subset of 24 Warthin–Starry positive lymphoma cases: of lymphoblastic lymphoma cases, 13/17 were positive for Hhe (p < 0.05; χ2 = 4.854). Hhe strains 2 and 4 were most commonly found (18/29 and 17/29, respectively) among sick cats, although a higher than expected number of cats was also positive for Hhe1, which initial reports have described as rare in cats and common in humans. The association found between a positive Hhe status with the presence of feline gastric lymphoma, especially lymphoblastic lymphoma, argues for the need to conduct prospective studies to better identify the frequency and strain distribution of Hhe infection in both healthy and clinically ill cats, particularly those cats with gastric lymphoma.  相似文献   

3.
Culicoides were captured at a BTV-infected dairy near Gulpen in the province of Limburg (south-east Netherlands) between 14 September and 4 October 2006. Onderstepoort-type blacklight traps were used to sample Culicoides both inside and outside a partially open shed housing 11 cattle. A total of 28 light trap collections were made at the shed and yielded:
• 9371 Culicoides representing 11 species; >90% comprised five potential vectors of BTV and in order of abundance were Culicoides obsoletus and Culicoides scoticus (of the Obsoletus Complex), Culicoides dewulfi, Culicoides pulicaris and Culicoides chiopterus; Culicoides imicola, the principal Mediterranean (and African) vector of BTV, was absent.
• 2339 Culicoides representing seven species were captured inside (endophily) the cattle shed; >95% comprised the Obsoletus Complex and C. dewulfi. Conversely, the Pulicaris Complex, represented by five species and including C. pulicaris, showed strong exophily with >97% captured outside the shed.
• 7032 Culicoides were captured outside the shed, approximately threefold more than inside. This trend was reversed on an overcast day, when eightfold more Culicoides were captured inside; this indicates that when the light intensity outdoors is low Culicoides will attack (i) earlier in the day while cattle are still at pasture, and (ii) might follow cattle into the sheds in the late afternoon leading to elevated numbers of biting midges being trapped inside the shed during the subsequent hours of darkness.
• Culicoides were captured inside the shed on all 14 sampling nights. On occasion up to 33% were freshly blood fed indicating they had avidly attacked the cattle inside (endophagy); because half the cattle had seroconverted to BTV, and because no cattle were left outdoors at night, the data indicate that (i) the housing of animals in partially open buildings does not interrupt the transmission of BTV, and/or (ii) BTV is being transmitted while cattle are grazing outdoors during the day.
• The capture of partially engorged midges inside the shed shows they are being disturbed while feeding; this may lead to cattle being attacked repeatedly, and if these attacks include older parous BTV-infected Culicoides, may enhance virus dissemination (particularly in sheds where cattle stand close together).
• Endo- and exophagy by potential vector Culicoides – coupled to increased adult longevity and multiple feeding events in single (potentially) infected midges – would ensure an R0 of >1, resulting in the continued maintenance and spread of BTV within local vertebrate populations.
• Four light trap collections made additionally in a mature deciduous forest 70 m from the shed yielded a high proportion (48%) of gravid females amongst which 10% had incompletely digested blackened blood meals in their abdomens; the absence of this age category in Culicoides captured at the sheds indicates that all Culicoides, after engorgement, exit the buildings to undergo oogenesis elsewhere.
In Europe, the blacklight trap is used widely for the nocturnal monitoring of Culicoides; a drawback to this approach is that this trap cannot be used to sample midges that are active during the day. Because diurnal biting in vector Culicoides may constitute a significant and underestimated component of BTV transmission a novel capture methodology will be required in future and is discussed briefly.  相似文献   

4.
  相似文献   

5.
The aim of this study was to determine the herd prevalence of veal and dairy herds and to identify risk factors for VTEC O157 positive veal herds. The study was based on monitoring data from November 1996 through July 2005 of 1051 dairy herds and 930 veal herds. The herd level prevalence (95% CI) was 8.0% (6.4–9.6) for dairy herds and 12.6% (10.5–14.7) for veal herds. Within the population of veal herds, a prevalence of 39.8% (33.9–45.6) was found for pink veal herds (n = 269) and 1.5% (0.7–2.8) for white veal herds (n = 661).Multivariable logistic regression showed that the type of veal (pink vs. white; OR = 21.6; 95% CI: 10.4–45.0), ventilation (mechanical vs. natural; OR = 0.4; 95% CI: 0.2–0.8), time between arrival in the herd and sampling (3–5 months vs. 0–2 months: OR = 2.33; 95% CI: 1.1–5.1, ≥6 months vs. 0–2 months: OR = 4.11; CI: 1.9–8.9), other feed than the 7 most common (yes vs. no; OR = 2.1; 95% CI: 1.2–3.7) and at least one dog present in the stable (yes vs. no; OR = 2.6; 95% CI: 1.5–4.6) were significantly (P < 0.05) associated with the presence of VTEC O157. The large difference in the VTEC O157 prevalences for pink veal and white veal production might have been caused by a very different management of these type of herds. However, this could not be studied with the data collected.  相似文献   

6.
The aim of the present study was to carry out molecular epidemiological investigation on enterotoxigenic Escherichia coli (ETEC) K99 and Salmonella spp. in diarrheic neonatal calves. Fecal samples were obtained from 220 diarrheic calves at 9 farms related to four governorates in central and northern Egypt. E. coli and Salmonella spp. isolates were examined for E. coli K99 and Salmonella spp. using PCR. ETEC K99 was recovered from 20 (10.36 %) out of 193 isolates, whereas Salmonella spp. was recovered from nine calves (4.09%).Multivariable logistic regression was used to evaluate the risk factors associated with both infections. ETEC K99 was significantly affected by age (P < 0.01; OR: 1.812; CI 95%: 0.566–1.769), colostrum feeding practice (P < 0.01; OR: 5.525; CI 95%: 2.025–15.076), rotavirus infection (P < 0.001; OR: 2.220; CI 95%: 0.273–1.251), vaccination of pregnant dams with combined vaccine against rotavirus, coronavirus and E. coli (K99) (P < 0.001; OR: 4.753; CI 95%: 2.124–10.641), and vitamin E and selenium administration to the pregnant dam (P < 0.01; OR: 3.933; CI 95%: 0.703–1.248).Infection with Salmonella spp. was found to be significantly affected by the animal age (P < 0.05; OR: 0.376; CI 95%: 0.511–1.369), Hygiene (P < 0.05; OR: 0.628; CI 95%: 1.729–5.612), and region (P < 0. 01; OR: 0.970; CI 95%: 0.841–1.624).The results of the present study indicate the importance of PCR as rapid, effective and reliable tool for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrhea may be helpful for construction of suitable methods for prevention and control.  相似文献   

7.
Elizabethkingia meningoseptica has been recognised as an occasional but serious opportunistic bacterial pathogen to human beings. Recently, it was frequently isolated from tiger frog, Rana tigerina rugulosa, with cataract disease, which is the most common disease of unknown aetiology of frogs in Hainan, China. The purpose of this study was to identify and characterise the bacterial strains isolated from the recent outbreaks of cataract disease in farmed tiger frog in Hainan, China, and to evaluate their pathogenicity to the frog and their sensitivity to 20 chemotherapeutic agents.The 16S rRNA gene sequences of strains W0701 (1478 bp), W0702 (1477 bp) and W0703 (1478 bp) showed 98.6–98.7% similarity with the sequence of E. meningoseptica type strain (ATCC 13253) and 99.9–100% similarity with that of E. meningoseptica NTU 870424-IL. Six strains (W0701–W0706) were selected to represent 24 isolates retrieved from six moribund frogs. The morphological, physiological and biochemical characteristics of the six representative isolates were consistent with those of E. meningoseptica strains. The organisms were only susceptible to vancomycin and moderately susceptible to cefoperazone among the 20 investigated chemotherapeutic agents. Virulence test with strain W0702 was conducted and pathogenicity (by intramuscular injection) was demonstrated in the tiger frog. In conclusion, 24 isolates obtained from frogs with cataract disease were the E. meningoseptica strains highly pathogenic to tiger frog, and this is the first report of E. meningoseptica as a pathogen for tiger frog.  相似文献   

8.
This laboratory study investigates the sub-adult developmental cycle of field collected Culicoides (Avaritia) imicola Kieffer (Diptera; Ceratopogonidae). The period required from blood-feeding field-collected females to the production of progeny adults occupied 34–56 days at 20 °C, 15–21 days at 25 °C and 11–16 days at 28 °C, demonstrating clear temperature dependence. When reared at 28 °C, C. imicola demonstrated higher variability in fecundity (between 2.4 and 20.6 eggs/female) and lower hatching rates (50.0–62.2%), although larval survival rates to pupation were low at all temperatures (20–30%). Similarly, the mean emergence rate from pupae was the highest at lower temperatures. These results highlight the difficulty in establishing and maintaining a laboratory colony of this species from field-collected material and results are discussed in reference to future research directions that may aid this process.  相似文献   

9.
Oestradiol-17β and testosterone blood plasma concentrations were measured in dogs with Leydig-cell tumours (n=20), Sertoli-cell tumours (n=6), seminomas (n=9), unilateral inguinal cryptorchidism (n=7), abdominal cryptorchidism (n=9, one bilateral), degenerate scrotal testicles (n=6, two bilateral), and animals with normal scrotal testicles (n=20). The testosterone/oestradiol ratio (testosterone concentration [ng/mL] × 100/oestradiol concentration [pg/mL]) was calculated.A considerably higher oestradiol concentration was found in dogs with Sertoli-cell tumours (29.0, 14.4–48.3 pg/mL; median, minimum–maximum; P=0.0256, Mann–Whitney test) and lower oestradiol levels were found in animals with seminomas (12.0, 3.4–17.6 pg/mL; P=0.0025) compared to the healthy control group (18.0, 8.6–31.5 pg/mL). Testosterone concentration was decreased in dogs with Sertoli-cell tumours (0.08, 0.03–0.77 ng/mL) when compared to the control group (1.95, 0.05–3.70 ng/mL; P=0.0012). Testosterone/oestradiol ratios differed from the control (9.6, 0.58–35.8) only in dogs with Sertoli-cell tumours (0.32, 0.06–2.80; P=0.0005). Clinical signs of feminization were observed in five dogs with Sertoli-cell tumour and one dog with a Leydig-cell tumour, and were more often associated with decreased testosterone/oestradiol ratios than with an increased oestradiol-17β concentration.  相似文献   

10.
Lechiguana is a disease of cattle characterized by large, hard, subcutaneous swellings that grow rapidly and result in death after 3–11 months in untreated animals. Cattle treated with antibiotics recover. The disease has been reported from five states in south and southeastern Brazil. Histologically, the lesion consists of focal proliferation of fibrous tissue infiltrated by plasma cells, eosinophils, lymphocytes and sometimes neutrophils. The primary lesion is an eosinophilic lymphangitis, which results in eosinophilic abscesses, with occasional rosettes containing bacteria in their centres. Much experimental and epidemiological evidence, reviewed in this article, supports the suggestion that lechiguana is caused by an association of Pasteurella granulomatis (syn: Mannheimia granulomatis) and Dermatobia hominis.  相似文献   

11.
Transferrin partial complementary DNAs were cloned from the livers of five species in four genera of Indian carps (Indian major carp species: Labeo rohita, Catla catla and Cirrhinus mrigala; medium carp: Puntius sarana; minor carp: Labeo bata) subsequent to polymerase chain reaction amplification with published heterologous primers or self-designed primers derived from conserved regions of transferrin cDNA sequences. The partial transferrin cDNAs of the five species of carps had sizes from 624 to 633 bp (487 bp for L. rohita) and encoded an open reading frame consisting of 206–211 (162 for L. rohita) amino acids. The alignments of carp cDNA sequences showed 85–97% homology and 71–93% homology in deduced amino acid sequences. A phylogenetic tree of amino acid sequences of transferrin cDNAs from carps showed that the relationship among the four genera of Indian carps is well correlated with that derived from classic morphologic analyses. The hypothesized cleavage site and interdomain bridge of transferrin molecule were predicted for the above carp species and interestingly the cleavage site amino acid sequence was found to be conserved among all the carps. To study the tissue-specific expression of the transferrin gene, various tissues (liver, kidney, spleen, brain, muscle, testis, heart, intestine, gill and fin) from apparently healthy (control), moribund and survived C. mrigala experimentally infected with Aeromonas hydrophila infection were analyzed. Transferrin mRNA was detected only in liver RNA and to lesser extent in brain tissue out of the 10 tissues analyzed irrespective of bacterial infection.  相似文献   

12.
  相似文献   

13.
A new field survey monitoring the spatial distribution of Dermacentor (D.) reticulatus (Fabricius, 1794) tick in Slovakia was carried out in 2005–2008 in order to record changes in its distribution when compared to former studies. Last surveys on the geographical distribution were conducted in 1950s and 1970s and the presence of D. reticulatus was determined along the rivers in the south-east (Latorica) as well as in the south-west (Morava, Dunaj) Slovakia. In the present survey new areas with D. reticulatus occurrence were detected, providing evidence that this tick species has extended its range in the surroundings of its former habitats but also by at least 200 km further North and by 300 m of elevation into higher altitudes. D. reticulatus is known to transmit Babesia spp. causing babesiosis in cattle and dogs. Expansion of D. reticulatus range is therefore likely to bring a spread of babesiosis, which can be severe or fatal especially for dogs.  相似文献   

14.

Background

Pathogens with the zoonotic potential to infect humans, such as Campylobacter jejuni, Campylobacter coli and Chlamydophila psittaci, can be found in feral pigeons (Columba livia). Given the high density of these birds in the public parks and gardens of most cities, they may pose a direct threat to public health.

Methods

A total of 118 pigeons were captured in three samplings carried out in 2006-2007 in public parks and gardens in Madrid, Spain. Standard haematological and morphological analyses were carried out on the pigeons. PCR was used to screen for the presence of Campylobacter jejuni, C. coli and Chlamydophila psittaci. Positive samples were confirmed by DNA sequencing.

Results

The analyses demonstrated a high prevalence of Chlamydophila psittaci (52.6%) and Campylobacter jejuni (69.1%) among the birds captured. In contrast, Campylobacter coli was rarely detected (1.1%).

Conclusions

Pigeons in Madrid can carry Chlamydophila psittaci and Campylobacter jejuni. They may be asymptomatic or subclinical carriers of both pathogens.  相似文献   

15.
Small volumes (0.05 ml) of cisterna magna cerebrospinal fluid (CSF) from 23 neurologically normal horses were analysed for the monoamine neurotransmitters dopamine, norepinephrine, epinephrine, serotonin and their metabolites using high pressure liquid chromatography and electrochemical detection. Two metabolites, homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were present in all CSF samples. The deaminated and methylated metabolite of dopamine, HVA, was present at a mean concentration of 42.33±3.14 ng/ml of CSF. The deaminated metabolite of serotonin, 5-HIAA, was present at a mean concentration of 45.52±3.65 ng/ml of CSF. A positive correlation was found between the CSF concentrations of HVA and 5-HIAA (r=0.72, p=0.0003). The mean ratio of HVA to 5-HIAA concentrations was 1.07±0.05. The ratios of HVA to 5-HIAA concentrations were found to be more indicative of the serotonergic metabolite 5-HIAA (r=–0.62, p=0.0016) than the dopaminergic metabolite HVA (r=0.11, p=0.60). There was a stronger relationship between the concentrations of 5-HIAA and the ratios of HVA to 5-HIAA in male CSF (r=–0.85, p=0.0006) than in female CSF (r=–0.54, p=0.01).Concentrations of CSF neurotransmitter metabolites were evaluated in horses grouped by age (0–4, 5–9 and 10–13 years). The youngest group of horses had a significantly (p=0.003) greater CSF concentration of HVA than of 5-HIAA. The 10–13-year-old horses had a significantly (p=0.02) lower mean CSF HVA concentration than the 0–4-year-old horses. No age-related differences in CSF 5-HIAA concentrations were detected.  相似文献   

16.
Matched samples of 100 chickens of each of growers and adult rural free-range chickens in Morogoro, Tanzania, were purchased from the beginning to the end of the long rainy season. At necropsy, the trachea, the gastrointestinal tract and the oviduct were examined for helminth infections. The helminth species isolated comprised 18 nematodes and 8 cestodes but no trematodes. Tetrameres fissispina is a new record in Tanzania. All the chickens harboured at least three different helminth species. Growers contained 4–14 and adults 3–12 helminth species. The number of species isolated per chicken increased as the rainy season advanced. The prevalence of the following species were significantly higher in growers than in adults (p<0.05); Ascaridia galli (69% of growers, 29% of adults); Syngamus trachea (14%, 3%); Tetrameres americana (94%, 82%); Trichostrongylus tenuis (43%, 7%); Choanotaenia infundibulum (15%, 6%); Davainea proglottina (9%, 2%); and Raillietina tetragona (36%, 21%). Allodapa suctoria (3%, 20%) and Capillaria annulata (1%, 10%) had a significantly lower prevalence in growers than in adults (p<0.05). There were significantly higher worm burdens (p<0.05) in growers than in adults for A. galli, Capillaria caudinflata, R. tetragona, S. trachea, T. americana, T. fissispina and T. tenuis. Conversely, A. suctoria and C. annulata showed significantly higher worm burdens in adults (p<0.05). The sex of the chickens influenced the burdens of Heterakis brevispiculum (p<0.05). There was an interaction effect such that growing males and adult females had statistically higher (p<0.05) burdens of T. tenuis and A. suctoria, respectively.  相似文献   

17.
To understand the epidemiology of Avian paramyxovirus serotype-1 (APMV-1) in pigeons in Japan, phylogenetic analysis was comprehensively conducted based on partial fusion protein gene using isolate from the surveillance of this virus with previously known Japanese pigeon strains. This surveillance was conducted using feces obtained from domestic pigeons collected in 40 prefectures throughout Japan from June 2011 to March 2013. From a total of 1,021 samples, a single virus (APMV1/pigeon/Japan/Kanagawa/2013: JP/Kanagawa-pg/2013) was isolated. All Japanese pigeon APMV-1 strains were clustered into a single genetic lineage, which was termed VIb/1 by phylogenetic analysis based on the F gene including the sequence of the cleavage site. These APMV-1 strains were further subdivided into four subgroups identified over 4 separate timeframes: 1984–1995 (group 1), 1995–2000 (group 2), 2001–2007 (group 3) and the novel subgroup isolated in 2013 (group 4). Each subgroup has specific amino acid motifs at a cleavage site of the F protein, namely, 112GRQKR-F117(except for one strain), 112RRKKR-F117, 112RRQKR-F117 and 112RRQKR-F117, respectively. Our data suggest that Japanese APMV-1 strains from pigeons were diverse and reinforced the possibility that there were multiple introduction routes from foreign countries into Japan.  相似文献   

18.
Trypanosoma evansi is generally considered a mild pathogen in bovines. However, in Asia, acute and chronic signs have been observed in cattle, with high levels of parasitaemia, abortion and death. Investigations in Asian cattle are needed to better understand this epidemiological situation. To generate comparable data at a regional level, development and standardization of an antibody-enzyme linked immunosorbent assay for T. evansi (ELISA/T. evansi) was initiated and applied in an epidemiological survey carried out in dairy cattle in Thailand. A batch of 1979 samples was collected from dairy farms located throughout the country's four regions. Soluble T. evansi antigens initially produced in France were also produced in Thailand for comparison and technology transfer. Screening of 500 samples allowed us to identify reference samples and to determine the cut-off value of the ELISA. Seropositive animals – some of them confirmed by PCR – were found in the four regions, in 12 out of 13 provinces, in 22 out of 31 districts, in 56 farms out of 222 (25%, 95%CI ± 6%) and in 163 animals out of 1979 (8.2, 95%CI ± 1.2%). Estimated seroprevalence in 35 farms ranged between 1% and 30%, and in 21 farms it was >30%. Approximately 25% of survey cattle were exposed to the infection, in various situations. A sub-sample of 160 sera was tested on both antigens. Wilcoxon's (Z = 1.24; p = 0.22) and McNemars's tests (CHI2 = 3.55; p = 0.09) did not show any significant differences, showing that the locally produced antigen is suitable for further evaluation in the surrounding countries. Use of this standardized serological method will broaden knowledge of the prevalence and impact of the disease at the regional level in South-East Asia. Further validation of this ELISA will be necessary in other host species such as buffalo, horse and pig.  相似文献   

19.
Twenty goats, in two groups of 10, were injected intradermally with Corynebacterium pseudotuberculosis. The doses of infection were 1×105 and 5×104 colony-forming units (cfu) for groups 1 and 2, respectively. Thereafter, a goat from each group was killed every 2–3 days and examined for gross and microscopic caseous lesions in the draining lymph nodes. Bands or zones of macrophages and polymorphonuclear granulocytes were observed microscopically on the second day of infection in both groups. Gross caseous lesions were observed from days 8 and 9 of infection, respectively. Positive bacterial agglutination test and haemolysis inhibition test titres were detected after 15–17 days and 20–25 days of infection, respectively. These results indicated that caseous lymphadenitis is a subacute disease with an incubation period of 8–9 days, but that it is not detectable serologically until after 15 days of infection.  相似文献   

20.
Selective muscarinic receptor antagonists were used to identify muscarinic receptor subtypes in equine trachealis strips. The M1 receptor antagonist pirenzepine (10–7 mol/L to 3 × 10–5 mol/L) and the M3 receptor antagonist 4-diphenylacetoxy-N-methylpiperidine (4-DAMP, 10–9 mol/L to 3 × 10–7 mol/L3) dose dependently inhibited the contractile responses to electrical field stimulation (EFS) and exogenous acetylcholine (ACh). Schild plots yielded a pA2 value for pirenzepine vs ACh of 6.75 ± 0.09, which is consistent with the affinity for M2 or M3 receptors, and a pA2 value for 4-DAMP vs ACh of 8.47 ± 0.09, which is in agreement with the affinity for M3 receptors. The M2 receptor antagonist gallamine (10–5 mol/L and 10–4 mol/L) did not affect the response of trachealis to exogenous ACh and low-frequency EFS (0.1–2 Hz) but decreased the responses to high-frequency EFS (4–16 Hz). These results suggest that the muscarinic receptors mediating contractions induced by ACh in equine tracheal smooth muscle are of the M3 subtype. The lack of an increase in the response to EFS following gallamine suggests that functional prejunctional inhibitory M2 receptors are not present on the cholinergic nerves innervating equine tracheal smooth muscle.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号