Comparing the results of intradermal skin tests for four dust mite allergens in dogs with atopic dermatitis in Thailand.

BACKGROUND AND AIM: Hypersensitivity to house dust mites is a common cause of atopic dermatitis in dogs. The intradermal test (IDT) identifies allergens to be included in allergen-specific immunotherapy. Common mite allergens used for IDT include single source extracts obtained from Dermatophagoides farinae or Dermatophagoides pteronyssinus or multisource extracts from multimite species (mixed mites), as well as a combination of multimite species and proteins from feces and shed skin (house dust). The objectives of the present study were to evaluate the prevalence of mite sensitivity in dogs diagnosed with atopic dermatitis in different Thailand provinces and to determine if positive test results to mite allergens aligned. MATERIALS AND METHODS: Eighty-two dogs (median age [range]: 5 years [11 months-11 years]; 51 males and 31 females) diagnosed with atopic dermatitis underwent IDTs with four different mite-related allergens (D. farinae, D. pteronyssinus, mixed mites, and house dust). The skin reactions were reported on a scale of 0-4 and the reactions 2+ were considered clinically relevant. The relationship between IDT results from different allergens was determined using Pearson's correlation coefficient (r). Fisher's exact test was used to compare IDT results for different mite allergens as well as for dogs residing in Bangkok versus other provinces in Thailand. RESULTS: The prevalence (95% confidence interval [CI]) of positive IDT results for D. farinae, D. pteronyssinus, mixed mites, and house dust in dogs with atopic dermatitis was 64.63% (52.30-74.88), 58.54% (47.12-69.32), 47.56% (36.41-58.89), and 35.37% (25.12-46.70), respectively. A moderate correlation was found in IDT results between D. pteronyssinus and house dust (r=0.514), between D. pteronyssinus and D. farinae (r=0.426), and between D. farinae and mixed mites (r=0.423). The prevalence of dogs with positive IDT results for mite allergens with mono-sensitization, bi-sensitization, tri-sensitization, and quadru-sensitization did not differ significantly between dogs residing in Bangkok (11.63%, 18.60%, 25.58%, and 16.28%) and dogs residing in other provinces (12.82%, 30.77%, 35.90%, and 10.26%). The overall sensitivity (95% CI) and specificity (95% CI) of the mixed mites test associated with atopic dermatitis in dogs were 60.32% (47.20-72.40%) and 94.70% (74.00-99.90%), respectively. The overall sensitivity (95% CI) and specificity (95% CI) of the house dust test associated with atopic dermatitis in dogs were 42.90% (30.50-56.00%) and 89.50% (66.90-98.70%), respectively. CONCLUSION: House dust mites are an important source of allergens for dogs with atopic dermatitis. In the present study, no significant difference in the prevalence of atopic dermatitis was found in dogs living in the urban area compared with dogs living in the countryside. Application of multisource extracts from mites for IDT revealed a higher reaction to mixed mites than that of house dust.

Quantitative and qualitative analysis of rat pup ultrasonic vocalization sounds induced by a hypothermic stimulus.

Ultrasonic vocalizations (USVs) are essential communicative sounds used between rodent pups and their mother. Rat pups emit USVs in stressful situations, such as when they are cold or separated from the nest. We verified the ontogenetic changes in USVs emitted by infant rats isolated from their mother during the pre-weaning period. The number of calls, and the median frequency and first peak of frequency of the calls were measured at 1, 3, 5, 7, 10, 12, and 14 days postnatal age in Wistar-Imamichi rats. Pups were placed in a cold glass beaker and USVs were recorded for 5 min. The number of calls increased to a peak on day 5 and then gradually decreased. The median frequency of calls decreased slowly during the first 12 days, and then increased slightly on day 14. Similarly, the first peak frequency of calls was the highest on day 1, and then decreased gradually by day 12. A small increase was observed on day 14. These changes in frequency were correlated with the physical development of the pups, whose body weights increased significantly with age except during postnatal days 7-10.

Improvement of hyperglycemia and sexual dysfunction in diabetic female rats by an artificial endocrine pancreas developed from mouse beta cells.

We investigated the effects of a bioartificial endocrine pancreas (Bio-AEP) produced by mouse beta cells on sexual dysfunction of streptozotocin (STZ)-induced diabetic female rats. Female rats were administered STZ (60 mg/kg BW, i.v.) at the age of 10 weeks and transplanted with a Bio-AEP including mouse beta cells at the age of 14 weeks (STZ+Bio-AEP group). Lordosis and proceptive sexual behavior of female rats were observed. The results showed that after the Bio-AEP transplant blood glucose recovered from 380-450 mg/dl induced by streptozotocin to 140-230 mg/dl and suppressed lordosis and proceptive behavior also recovered. These results suggest that it is possible to reverse sexual dysfunction by continuous administration of mouse insulin.

Plasma prolactin concentrations and copulatory behavior after salsolinol injection in male rats.

PURPOSE: The dopamine-derived endogenous compound, R-salsolinol (SAL), was recently identified as a putative endogenous prolactin (PRL)-releasing factor. However, how SAL influences copulatory behavior is unknown. In this study, we examined the relationship between SAL and copulatory behavior in male rats. METHODS: Male Sprague-Dawley rats administered SAL were exposed to female rats in estrus, the plasma PRL concentration was measured, and the behavioral frequency and time during copulatory behavior were noted. RESULTS: In the control and SAL groups, plasma PRL concentrations at 15 min before exposure to the female were 7.3 ± 2.0 and 8.0 ± 1.5 ng/ml, respectively. Moreover, plasma PRL concentrations in males immediately after exposure to the female were 7.4 ± 1.2 and 68.0 ± 5.9 ng/ml, respectively (P < 0.05). All (8/8) of the control animals ejaculated in the presence of the female, whereas only 33% (2/6) of the SAL group ejaculated. An increasing tendency for mount latency and intromission latency and a decreasing tendency for intromission frequency were observed in the SAL group. CONCLUSIONS: Copulatory behavior was inhibited in male rats after SAL injection, suggesting that SAL is a copulatory behavior inhibiting factor.

Time-dependent changes in cardiovascular function during copulation in male rats.

PURPOSE: Sudden cardiac death after ejaculation has been reported in humans and highlights the important relationship between sexual behavior and the heart. The rat is an extremely useful animal model for investigating reproductive function in male mammals. In this study, we examined the relationship between autonomic nervous system activity and the circulatory system during sexual behavior in male rats. METHODS: Male Wistar-Imamichi rats were exposed to female rats in estrous and heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and plasma noradrenaline (NA) and adrenaline (Ad) concentrations were measured by telemetry during copulation. RESULTS: The resting HR was 365.5 ± 18.4 beats/min (mean ± SE), which increased to 531.2 ± 21.1 beats/min at ejaculation and decreased to 404.6 ± 30.7 beats/min 1 min after ejaculation. At rest, SBP and DBP were 123.8 ± 6.6 and 81.5 ± 4.1 mmHg, respectively, which increased to 154.5 ± 5.9 and 112.1 ± 7.3 mmHg at ejaculation. Baseline plasma Ad and NA concentrations were 151.6 ± 32.0 and 248.5 ± 22.5 pg/ml, respectively, and these increased to 393.8 ± 89.9 and 792.7 ± 154.0 pg/ml at ejaculation, after which they decreased to resting levels. The rate of increase in NA at ejaculation differed significantly from that of Ad. CONCLUSIONS: The load on the circulatory and autonomic nervous systems is controlled by a rapid decrease in HR and NA concentration immediately after ejaculation, such that the male rat is prepared for the next copulation.

Correlation between body weight (epididymal fat) and permeation rate of serum leptin through the blood-brain barrier (BBB) in male rats aged 8 months.

In this study, in order to clarify the kinetics of leptin, we focused on the ratio of leptin concentrations in cerebrospinal fluid and serum in aged male rats, and examined the weight of epididymal fat, and the passage rate of leptin through the blood-brain barrier. In the lighter animals, the epididymal fat weight was low, while leptin concentrations in the serum and cerebrospinal fluid were also low. Conversely, in the heavier animals, the weight of epididymal fat and leptin concentrations in the serum and cerebrospinal fluid were higher. With regard to the ratio of leptin in the cerebrospinal fluid and serum, the passage rate of leptin through the blood-brain barrier was lower in the heavier animals than in the lighter animals.

Effects of single or repeated administrations of methamphetamine on immune response in mice.

The present study aimed to clarify the connection between immune responses and the administration frequency of methamphetamine (MAP) in male and female mice. Male and female ddY mice were given single or multiple (repeated for 10 days) intraperitoneal injections of MAP (5.0 mg/kg/day). The following immune parameters were examined; the number of leukocytes in peripheral blood and the proliferative activity (phytohemagglutinin;PHA, lipopolysaccharide; LPS response) and natural killer (NK) cell activity in splenic lymphocytes. Further, the differences in metabolic function in the spleen in response to MAP (and its metabolite amphetamine) in male and female mice were measured by gas chromatography. The results of the present study were that; 1) single and repeated MAP injections reduced leukocytes; 2) single MAP injection increased the proliferative response of splenic lymphocytes to PHA stimulation in only male mice, but the response to LPS stimulation was slightly increased in both male and female mice; 3) single and repeated MAP injections reduced NK cell activity of splenic lymphocytes, and especially in female mice with 5 injections of MAP; 4) with 10 MAP injections the NK cell activity and leukocytes recovered to the level of controls; and 5) the metabolic activity of MAP was reduced in female mice treated acutely with MAP in comparison to male mice. These results appear to indicate that immune responses to MAP were involved in the different results shown for administration frequency, sex difference and metabolic process of MAP.

Ontogenetic changes of ultrasonic vocalizations emitted from infant rats.

Ontogenetic changes of USVs were investigated to establish an index of stress in infant rats. The USVs were obtained by exposing infant rats to cold stress and were analyzed by real-time spectrography. USV waveforms consisted of four types, R-I, II, III and IV. These USVs were closely monitored at the age of 3-7 days in both sexes. From day 14, the frequency and incidence of USVs gradually decreased and had disappeared completely at the age of 21 days. Therefore, USVs should be useful in estimating the stress of infant rats between the ages of 3-7 days.