Search Results (187)

Background/Objectives: Opioid use disorder (OUD) remains a severe health problem globally, resulting in substantial social and economic challenges. While existing medications for managing OUD are proven to be effective, they also present certain challenges. A vaccine offers a promising therapeutic strategy to combat OUD and potentially reduce the risk of overdose death. The TT-6-AmHap heroin conjugate vaccine has effectively reduced heroin-induced pharmacological effects in behavioral assays as well as demonstrated the induction of high titer and high affinity antibody responses in mice and rats. In this GLP study conducted in rabbits, the potential local and systemic toxicity of the TT-6-AmHap heroin vaccine in combination with or without adjuvants ALF43 and Alhydrogel^® (ALFA) was investigated. Methods: Male and female New Zealand White rabbits were administered with vaccines or a saline control intramuscularly at two-week intervals over a 57-day study period. The presence, persistence or reversibility of any toxic effects of the vaccine was determined over a four-week recovery period. Results: Administration of TT-6-AmHap with or without the adjuvants induced high antibody-specific IgG in treatment groups compared to the controls. The study found no TT-6-AmHap-related effects on mortality, physical examinations, dermal Draize observations, body weights, body weight changes, food consumption, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, and urinalysis), macroscopic pathology, or organ weights. Conclusions: Under the conditions of this study, these results demonstrate that the TT-6-AmHap vaccine with or without adjuvants was well tolerated, immunogenic, and the effects were not considered adverse in both male and female rabbits. Full article

Background: Adrenal glands are situated cranially and in close proximity to both kidneys. The rabbit is a preferred animal pet species and is also used as an experimental model in research. The aim of this study was to investigate the CT anatomical features of the rabbit adrenal glands, using the CT device SOMATOM. Methods: Ten sexually mature clinically healthy rabbits, with body weights from 2.5 to 3.0 kg were used. They were separated into two groups—five males and five females. CT algorithm: Transverse, sagittal, and dorsal CT studies were performed. The animals were positioned in supine recumbency. They were anesthetized with 15 mg/kg Zoletil^® 50. Helical CT was carried out. The body was scanned from the intrathoracic part of the abdominal cavity to the pelvic inlet. CCD, DVD, and MLD dimensions were measured. Results: Transverse CT scans at the Th12 and L1 level visualized the topography of the right and left adrenal glands. Sagittal CT scans of Regio abdominis, 10 mm to the right and to the left of the median plane, showed the right and left adrenal glands as findings with intermediate attenuation. The dorsal CT investigation of Regio abdominis 30 mm and 45 mm ventral to the spine demonstrated both glands in the vicinity of abdominal organs and large blood vessels. CCD of the right adrenal gland was 6.9 ± 0.5 mm, DVD of the same gland was 5.7 ± 0.7 mm, and MLD was—3.9 ± 0.3 mm. CCD of the left adrenal gland was 5.4 ± 0.6 mm, DVD was—4.0 ± 1.1 mm, and MLD was—4.1 ± 0.9 mm. Conclusions: CCD and DVD of the right adrenal gland were greater than the same parameters of the left gland. MLD of the right adrenal gland was lower than the same parameter measured for the left one. Full article

Goji berries (Lycium barbarum), rich in antioxidant and immunomodulatory compounds, have shown potential benefits for male reproductive health. This study aimed to evaluate the impact of dietary Goji berry (GB) supplementation on immune-related and antioxidant gene expression in the male reproductive tract of rabbits. Eighteen 7-month-old New Zealand White rabbit bucks were randomly assigned to two groups: a control group (n = 9) receiving a standard diet, and a Goji group (n = 9) receiving the same diet supplemented with 1% GB. After 60 days of nutritional adaptation and then 60 days of treatment, tissues from the testes, epididymis, seminal vesicles, prostate, and bulbourethral glands were collected and analyzed using quantitative real-time PCR. Gene expression analysis focused on immune markers (TLR4, IL-1β, IL-10, and TNFα) and antioxidant enzymes (SOD1, CAT, and GPX). Significant modulation was observed only in the epididymis, where TLR4 and GPX were significantly downregulated in the Goji group (p = 0.0274 and p = 0.007, respectively), while IL-1β and TNFα showed a downward trend. No significant differences were found in the other tissues. These results suggest that Goji berry supplementation exerts tissue-specific effects, particularly in the epididymis, by modulating inflammation and oxidative stress. This supports its potential use as a natural nutraceutical strategy to enhance male fertility in rabbits. Full article

This study was conducted on New Zealand White male and female rabbits over a period of 133 days to ascertain their potential growth rates, body composition for major body parts, and chemical makeup. A total of 220 New Zealand White rabbits, evenly distributed between males and females, were used for this study. One hundred rabbits for potential growth were weighed from day 14 to day 140, while twelve rabbits, six males and six females, were randomly selected at days 14, 21, 28, 35, 42, 56, 70, 84, 112, and 140 for carcass analysis. Although the rate of maturation was faster in females than in males, the Gompertz equation fitted separately to the growth data for males and females indicated that the body weights were similar throughout the trial (0.0243 vs. 0.0239), but males had a higher mature weight (315 g) than the females (309 g). Mature body protein weights averaged 1497 g in males and 843 g in females, and mature body lipid contents averaged 252 and 227 g, respectively. The rate of maturation per day of pelt-free body protein of males and females was 0.0103 and 0.0172, while that of body lipids was 0.0410 and 0.0471, respectively. Separate equations were required for males and females to describe the allometric relationship between protein and lipids in the pelt-free body. The rate of maturation of pelts in females was higher than in males (0.0249 vs. 0.0214/d), and the mature weight was lower (456 vs. 523 g, respectively). Full article

This study evaluated the effect of two levels of extruded linseed (EL) in the diet on growth performance, carcass yield, and meat quality of growing rabbits. Sixty-nine New Zealand White male rabbits (Oryctolagus cuniculus) were assigned after weaning to three dietary groups: control (C), 2.5% EL (L2.5%), and 5% EL (L5%). At the end of the fattening period (from 37 to 93 days of age), rabbits were slaughtered. EL supplementation significantly reduced average daily weight gain (ADG) in the L5% group (p < 0.05), while other performance parameters were not significantly affected. Meat from the L5% group exhibited a higher fat content (p < 0.001) and lower water-holding capacity (p < 0.05) compared to the others. The fatty acid profile showed a significant increase in n-3 polyunsaturated fatty acids (PUFAs) and a decrease in n-6 PUFA (p < 0.05), resulting in a markedly reduced n-6/n-3 ratio (p < 0.001) in supplemented groups. EL supplementation also enhanced long-chain n-3 PUFA levels, particularly docosapentaenoic acid (DPA). Although lipid oxidation was slightly increased (p < 0.05), sensory attributes remained unaffected. These findings support EL supplementation as a nutritional strategy to increase the n-3 fatty acids in rabbit meat without compromising physical and sensory quality. Full article

Extensive bone loss represents a great challenge for orthopedic and reconstructive surgery. On an in vivo rabbit model, the healing of two bone defects on a long bone, tibia, was studied. A polybutylene succinate (PBS) microfibrillar scaffold was implemented with BMP-2 protein and hydroxyapatite (HA) as potential osteogenic factors. The present study was carried out on 6 male New Zealand white (4–6 months old) rabbits in vivo model. One bone defect was created in each subject on the tibia. The controls were left to heal spontaneously while the study samples were treated with the polybutylene succinate (PBS) microfibrillar scaffolds doped with BMP-2 and HA. Histological and immunohistochemical analyses were performed after euthanasia at 3 and 6 months. The bone defect treated with the BMP-2 PBS scaffold shows, from 3 months, a significantly increased presence of activated osteoblasts with mineralized bone tissue deposition. This study confirms the great potential of PBS scaffolds in the clinical treatment of bone defects. Full article

The abdomen is a key region in small animal veterinary practice, with the middle and caudal sections housing various organ systems that are susceptible to dysfunction, necessitating medical intervention or surgery. Sectional imaging techniques like CT and MRI are commonly used in small mammals, but no studies have focused on rodent abdomen. This study aimed to correlate micro-CT and MRI images of the middle and caudal abdominal regions with corresponding anatomical sections in Syrian hamsters (SHs), which are popular pets and experimental models. Ten healthy male SHs were used, and anatomical structures from frozen sections were compared with corresponding MCT and MRI images. Clinically relevant structures identified in anatomical sections were discernible on MCT and MRI scans. The key findings include the presence of glandular and non-glandular stomachs, the stomach and cecum primarily located on the left side, the absence of ampulla coli, sacculus rotundus, and cecal appendix, and sacculation of the colon, as well as the jejunum, mainly on the right side. The vesicular, coagulating, and prostate glands were also present, and the right kidney did not extend to the last thoracic vertebra. The results were similar to abdominal anatomical and radiologic studies in rats, mice, and guinea pigs, regardless of the rat’s and mice’s sacculated cecum and the guinea pig’s glandular stomach. However, significant differences were observed compared to the rabbit abdomen’s sectional anatomy and CT findings. This study highlights the diagnostic value of MCT and MRI in SHs and provides a valuable reference for interpreting cross-sectional abdominal images in SHs. Full article

High-fat diets (HFDs) have been found to compromise male fertility, with cholesterol dysregulation being a key factor. Sterol regulatory element-binding protein 2 (SREBP2) is a crucial transcription factor that regulates cholesterol biosynthesis and uptake, playing an essential role in maintaining cholesterol homeostasis in the testes. This study investigated the dynamics of SREBP2 and cholesterol levels during rabbit spermatogenesis under HFD conditions. Our findings reveal that SREBP2 expression fluctuates throughout the seminiferous epithelium cycle. However, HFDs induce stage-specific disruptions in cholesterol balance, leading to sperm with increased membrane cholesterol, a reduced sperm count in semen analysis, impaired motility, abnormal morphology, and decreased functionality. In the control group, SREBP2 expression patterns underscored its critical role in normal spermatogenesis. Interestingly, supplementation with extra virgin olive oil (EVOO) reversed the negative effects of HFD, normalizing SREBP2 expression and cholesterol content, which improved sperm quality. These findings emphasize the importance of stage-specific analysis in understanding how dietary fat impacts male fertility and suggest that EVOO may serve as a potential nutritional intervention to protect reproductive health. Full article

One hazardous material that occurs naturally in the environment and induces oxidative stress is cadmium (Cd). Epidemiological data revealed that exposure to cadmium in the workplace and environment might be linked to many illnesses and serious testicular injuries. Aims: It is taught that antioxidants can protect different organs against environmental toxic compounds. Therefore, the current investigation aims to show the role of antioxidants (gallic acid and selenium) in the protection against cadmium toxicity, including the architecture of the testes, semen properties, steroid hormones, protein expression of cytochrome P450 [CYP 19 and 11A1] contributing to the production of steroid hormones, and antioxidant enzyme activities, in male rabbits. Methods: Male rabbits were given cadmium orally three times/week [1 mg/kg BW] for twelve weeks. In addition, gallic acid (20 mg/kg) or selenium (1 mg/kg BW) was administered two hours before cadmium treatment. This investigation included a spectrophotometer, histopathology, and Western immunoblotting techniques. Results: Cadmium treatment significantly reduced sperm counts, testosterone, and estrogen levels after four, eight, and twelve weeks of treatment. In addition, after a 12-week treatment of rabbits with cadmium, the activity of 17β-hydroxysteroid dehydrogenase and antioxidant enzymes, including catalase, superoxide dismutase, glutathione reductase, glutathione peroxidase, and glutathione S-transferase, as well as the glutathione levels, were inhibited in the testes tissue. On the other hand, following cadmium treatment, rabbit’s testes showed a discernible increase in free radical levels. Interestingly, the activity of antioxidant enzymes and level of free radicals were recovered in rabbits treated with gallic acid or selenium before cadmium treatment. In addition, after 12 weeks of cadmium treatment, the steroidogenic protein expressions of CYP 11A1 and CYP 19 were upregulated and downregulated in the testes, respectively. Interestingly, after pretreatment of rabbits with either gallic acid or selenium for two hours before cadmium administration, the downregulated CYP11A1 was restored to normal levels. In the histopathological investigation, immature spermatozoids and sloughed spermatogonium cells were observed in cadmium-treated rabbits’ testes. On the other hand, pretreatments of rabbits with gallic acid or selenium mitigated and alleviated the adverse effects of cadmium on testes architecture and increased the production of healthy sperm. Conclusions: The lower levels of steroid hormones could be due to the downregulation of CYP11A1, inhibition of 17β-hydroxysteroid dehydrogenase, antioxidant enzyme activities, and the induction of free radical levels. Furthermore, the pretreatment of rabbits with gallic acid or selenium mitigated the adverse effects of cadmium on the tissue architecture of testes and steroid hormone levels. Full article

Rabbits are commonly affected by subclinical lung diseases. Computed tomography (CT) is the gold standard for diagnosing rabbit lung diseases but is not widely available and requires anesthesia, delaying diagnosis. Lung ultrasound (LUS) has emerged as a radiation-free, bedside diagnostic tool in human and veterinary medicine, though its use in rabbit medicine is not routine. This study aimed to evaluate LUS for detecting subclinical lung lesions in rabbits. Thirty healthy, five-month-old male New Zealand white rabbits underwent lung ultrasound, exploring four regions in each hemithorax, followed by thoracic CT under sedation with midazolam and butorphanol. The ultrasound images were scored as positive or negative, and the CT exams were assessed for aeration using threshold masks. The results showed that 63% of rabbits had one or more affected regions in the ultrasound images, and 19% of the regions were positive. CT identified 54% of the regions as positive for poorly aerated tissue, with 26/30 rabbits showing at least one positive region. The sensitivity and specificity of LUS were 33.33% and 93.48%, respectively, with an accuracy of 67.92% for detecting subclinical lesions. While LUS demonstrated a high specificity, its sensitivity was low compared to CT, highlighting the need for further refinement in its use for rabbit respiratory disease diagnosis. Full article

Traumatic or degenerative defects of articular cartilage impair joint function, and the treatment of articular cartilage damage remains a challenge. By mimicking the cartilage extracellular matrix (ECM), exosome-seeded cryogels may enhance cell proliferation and chondral repair. ECM-based cryogels were cryopolymerized with gelatin, chondroitin sulfate, and various concentrations (0%, 0.3%, 0.5%, and 1%) of hyaluronic acid (HA), and their water content, swelling ratio, porosity, mechanical properties, and effects on cell viability were evaluated. The regenerative effects of bone marrow-derived mesenchymal stem cell (BM-MSC)-derived exosome (at a concentration of 10⁶ particles/mL)-seeded 0.3% HA cryogels were assessed in vitro and in surgically induced male New Zealand rabbit cartilage defects in vivo. The water content, swelling ratio, and porosity of the cryogels significantly (p < 0.05) increased and the Young’s modulus values of the cryogels decreased with increasing HA concentrations. MTT assays revealed that the developed biomaterials had no cytotoxic effects. The optimal cryogel composition was 0.3% HA, and the resulting cryogel had favorable properties and suitable mechanical strength. Exosomes alone and exosome-seeded cryogels promoted chondrocyte proliferation (with cell optical densities that were 58% and 51% greater than that of the control). The cryogel alone and the exosome-seeded cryogel facilitated ECM deposition and sulfated glycosaminoglycan synthesis. Although we observed cartilage repair via Alcian blue staining with both the cryogel alone and the exosome-seeded cryogel, the layered arrangement of the chondrocytes was superior to that of the control chondrocytes when exosome-seeded cryogels were used. This study revealed the potential value of using BM-MSC-derived exosome-seeded ECM-based cryogels for cartilage tissue engineering to treat cartilage injury. Full article

Lipopolysaccharide (LPS)-induced inflammation impairs sperm function; however, its impact on ejaculated rabbit sperm remains unexplored. This dose-response study aims to determine the LPS concentration that negatively affects sperm motility in vitro, while also providing the first identification of TLR4 localization on rabbit spermatozoa. Additionally, it evaluates malondialdehyde (MDA) levels in seminal plasma as an indicator of oxidative stress. Sperm motility was analyzed using computer-assisted sperm analysis (CASA) after incubation with increasing LPS concentrations (0, 50, 100, 200, 400, 600, and 800 µg/mL) at multiple time points (0, 1, 2, and 4 h). LPS doses ≥ 400 µg/mL significantly reduced progressive and non-progressive motility, as well as curvilinear velocity (all p < 0.001), while increasing the proportion of static spermatozoa (p < 0.05). Receiver operating characteristic (ROC) analysis identified 300 µg/mL as the threshold dose for motility decline. Immunofluorescence revealed TLR4 localization in the midpiece of sperm tails, with weak labeling in control samples and a marked increase after 4 h of incubation with 400 μg/mL LPS. MDA levels were assessed using the thiobarbituric acid reactive substances (TBARS) assay with a colorimetric kit, showing no significant effect of LPS treatment. No correlation was found between MDA and other semen parameters. ccThese findings identify TLR4 on rabbit sperm for the first time and establish a threshold LPS dose for future in vitro studies. Full article

Recent advancements in ocular physiology suggest that the eyes may function similarly to radar antennae or ultrasound probes, with the occipital cortex acting as a detector, challenging the traditional view of binocular vision as the primary mechanism for depth and distance perception. Methods: We conducted a comprehensive analysis of the neuroanatomical and histological architecture of the neuro-optico-cortical systems in a male wild rabbit model. The objective was to identify potential structural and functional similarities between the retino-optical system and radar/ultrasound effector-detector systems. Results: Histological examination revealed significant similarities between retinal morphology and radar/ultrasound systems. The outermost retinal layer resembled an acoustic lens, with underlying layers functioning as acoustic matching layers. The ganglion cell layer exhibited characteristics akin to the piezoelectric elements of transducers. Conclusions: Our findings support the hypothesis that the retinal apparatus functions similarly to radar antennae or ultrasound probes. Light-stimulated retinal-occipital cortex cells perceive objects and emit electromagnetic waves through the retina, which are reflected by objects and processed in the occipital cortex to provide information on their distance, shape, and depth. This mechanism may complement binocular vision and enhance depth and distance perception in the visual system. These results open new avenues for research in visual neuroscience and could have implications for understanding various visual phenomena and disorders. Full article

The main objective of this research was to observe the effects of feed restriction on caecum microbiota and metabolites in rabbits. Forty-eight male 8-week-old rabbits with similar body weights (1872.11 ± 180.85 g) were randomly assigned to two treatments according to completely randomized design: (1) the control group received ad libitum access to feed (AL), and (2) the treatment received 80% of the feed consumed by the control (FR). The results showed that FR did not differ (p > 0.05) for average daily weight gain or feed conversion ratio between the two groups. FR treatment led to a significant increase (p < 0.05) in acid detergent fibre apparent faecal digestibility, nitrogen digestibility and retention, and gross energy digestibility and retention. The FR treatment showed significantly (p < 0.05) lower blood triglycerides, creatinine, high-density lipoprotein cholesterol, malondialdehyde, and hydroxyl free radicals but significantly (p < 0.05) greater total antioxidant capacity and superoxide dismutase. The FR group presented greater (p < 0.05) Firmicutes and Ruminococcus abundances but a lower (p < 0.05) Akkermansiaceae abundance in the caecal content. Moreover, 222 differentiated metabolites were identified, and beta-alanine metabolism was the top enriched pathway. Collectively, FR can improve nutrient utilisation, lipid metabolism, antioxidant activity, caecum microbiota, and metabolites in rabbits. Full article

This study examined epidemiological aspects of rabbit pathologies, identified bacterial strains, and assessed their antimicrobial resistance, emphasizing rabbits as potential reservoirs for zoonotic multidrug resistant (MDR) bacteria and the need for continuous monitoring and antimicrobial stewardship. Samples from rabbits were cultivated and then identified using Vitek^® 2 and MALDI-TOF. Antimicrobial susceptibility was assessed by disk diffusion testing. This study analyzed 170 individuals with various pathologies, with males (58.24%) outnumbering females (41.76%). Dental abscesses (35.29%) and respiratory infections (28.24%) were most common. Antibiotic exposure was noted in 47.06% of cases, primarily involving trimethoprim (35.56%). Of the total samples, 91.18% tested positive, revealing 200 isolates from 23 bacterial genera, with Staphylococcus spp. (31%) and Escherichia coli (12%) being most frequently identified as well as species with zoonotic potential, such as Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis, and Enterococcus faecium. Antimicrobial susceptibility testing showed high efficacy for florfenicol (75%), ciprofloxacin (74.12%), and amikacin (68.65%), while significant resistance was found for kanamycin, neomycin, and trimethoprim. Nearly 49% of strains were MDR, with Gram-positive cocci, Enterobacteriaceae, and non-Enterobacteriaceae showing varying resistance, across 18 MDR genera. In conclusion, pet rabbits are potential reservoirs of zoonotic and MDR bacterial species, posing a risk for their owners. Full article