Dutch Rabbits Research Articles

Effect of a single versus serial platelet-rich plasma injection on the healing of acute patellar tendon defect: an experimental study

BackgroundThere is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation.MethodsForty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups ( A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin’s Grading) and biomechanically.ResultsThe inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections.ConclusionsPRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery.

Seminal Morphology and Organ Morphometrics of Rabbit Bucks Fed Piliostigma thonningii Essential Oil Supplemented Diet

This study aimed to investigate whether the inclusive supplementation of Piliostigma thonningii essential oil in rabbit diet was beneficial to their seminal morphometrics. Forty-five clinically healthy weaned male Dutch rabbits of about five weeks of age were used for the experiment. The rabbits were divided into three treatment groups, with fifteen rabbits per group and balanced for their body weight such that rabbits in each group had similar average initial BW of 0.27 kg. The experimental rabbits were administered P. thonningii essential oil at 0, 2 and 4 ml/kg for treatments T1, T2 and T3, respectively for 12 weeks. The results showed that left testis weight increased with increasing levels of P. thonningii essential oil supplementation. The normal cells, right testis weight and right and left testis volume were higher in T2 and T3 treatments than in T1. Right and left testis lengths were higher in T3 treatment than T1, with T2 being intermediate between T1 and T3. Mid-piece droplet, coiled tail, detached head, free tail, bent tail, right and left epididymis volume, head weight and length, body weight and length, weight and tail length and weight were not affected by treatments. It is concluded that P. thonningii essential oil supplementation improved some organ morphometrics without necessarily affecting sperm morphology in the experimental rabbit bucks.

A Glance at Common Digestive Diseases in Rabbits

Rabbits are cherished pets and valuable animals in various fields, including agriculture and science. The popularity of pet rabbits has surged, with various breeds such as the Lionhead Rabbit, Holland Lop Rabbit, Mini Rex Rabbit, Polish Rabbit, and Dutch Rabbit gaining traction. With proper diet and living conditions, rabbits can live up to ten to twelve years. However, domestic rabbits are prone to several infectious diseases, including parasitic, bacterial, and viral infections. The most common ailments in rabbits are skin conditions, respiratory infections, and digestive system issues. Understanding these common diseases is essential for maintaining the health and well-being of rabbits. This review article provides a comprehensive overview of the prevalent illnesses affecting rabbits, detailing their causes, symptoms, prevention methods, and available treatments.

The Comparative Study on Effect of Breed and Gender on Some Carcass Traits of New Zealand White and Dutch Rabbit Breeds

This study was designed to observe the effect of breed on some carcass traits of New Zealand White and Dutch rabbit breeds. In this study, 2 males and 8 female Breeder Rabbits from New Zealand White and Dutch rabbit breeds were purchased from a local farmer and allowed for breeding purposes by the ratio of 1:4 Male to Female in different cages. From the first filial generation, 80 kits were randomly selected after weaning at 21-25 days and grouped into A, B, C, and D. Groups A and C included males of New Zealand White and Dutch breeds, whereas B and D included females. Their live weight at 80 days was observed, and lastly, they were slaughtered to observe the effect of breed on carcass traits. Dutch breed males showed significantly higher (P<0.05) weaning weight, live weight, slaughter weight, carcass weight, boneless weight, bone weight and dressing percentage compared to New Zealand White males, while Dutch females also exhibited higher traits compared to New Zealand White females. The results indicated that Dutch rabbits had higher birth weight, weaning weight, live weight, slaughter weight, carcass weight, boneless weight, bone weight, and dressing percentage as compared with New Zealand White breeds.

Niche partitioning and competition between different rabbit breeds using stable isotopes

Stable isotope analysis (SIA) is an evolving method for determining diet, understanding food web and resolving biogeochemical issues in the ecosystem. This study aims to trace out ecological niche preferences/partitioning and competition among the lagomorphs, including two different breeds of European rabbit (Oryctolagus cuniculus), New Zealand rabbit and American Dutch rabbit, using SIA. Thirty-two samples of tooth enamel were analysed, which were collected from different districts of Punjab, Pakistan, including Okara, Sahiwal and Kasur. Among these samples, 16 belonged to the New Zealand breed (08 male and 08 female rabbits) and 16 to the American Dutch breed (08 male and 08 female rabbits). Significant (P<0.001) intergender differences in the isotope content of δ13C in the enamel for New Zealand and American Dutch rabbit were found. The European rabbits showed significant differences for both genders in the stable isotope of oxygen in the enamel (δ18O) values (P=0.05). Nitrogen stable isotope results showed no significant intergender differences between American Dutch and New Zealand rabbits (P=0.24). The stable isotope results for δ13C, δ15N, and δ18O indicate that the trophic niche partitioning of both breeds overlaps, which can potentially cause competition for resources, whereas the water intake may differ among different genders, which may reflect differential gender-related activities. The archaeological and fossilised data of lagomorphs is present, but there is no significant literature available for living lagomorphs (rabbits). In general, this study provides a basic and first dataset for δ13C, δ15N, and δ18O of living lagomorphs, which can serve as a comparative dataset for future studies.

Growth, survival rate of New Zealand White, Dutch Rabbit and their crosses

Abstract. The aim of the study was to assess survival rate of crossbred New Zealand White and Dutch rabbit breed. A total of 16 mature rabbits of seven to nine months old, New Zealand White and Dutch were used for the study. Data obtained were subjected to analysis of variance ANOVA using SAS. The reproductive traits studied were litter size, litter birth weight, mean kit weight. The growth traits were: body weight, body length, ear length, chest circumference, hind limbs, thigh length, nose to shoulder and thigh circumference. The reproductive traits were significantly (P<0.05) affected by genetic group Pure and crosses. New Zealand White observed high litter size and litter birth weight at first, seventh, 14th and 21st day. Purebred Dutch had significant (P<0.05) high values for growth traits. The body weight 478.73±18.10, body length 33.12±0.42, ear length 9.10±0.09, chest circumference 18.24±0.45 and hind limbs 19.51±0.33 were significantly (P<0.05) high in crosses of Dutch x New Zealand White. Pre-weaning mortality and survival rate at weaning were 22.22% and 77.77% high in New Zealand White; 14.28% and 85.71% in Dutch and DUC x NZW; and 9.09% and 90.90% in NZW x DUC. In conclusion, New Zealand White x Dutch crosses demonstrated high survival rate and low pre-weaning mortality.

Development of a rabbit model of Adenosine triphosphate-induced monocular retinal degeneration for optimization of retinal prostheses.

Optimization of retinal prostheses requires preclinical animal models that mimic features of human retinal disease, have appropriate eye sizes to accommodate implantable arrays, and provide options for unilateral degeneration so as to enable a contralateral, within-animal control eye. In absence of a suitable non-human primate model and shortcomings of our previous feline model generated through intravitreal injections of Adenosine Triphosphate (ATP), we aimed in the present study to develop an ATP induced degeneration model in the rabbit. Six normally sighted Dutch rabbits were monocularly blinded with this technique. Subsequent retinal degeneration was assessed with optical coherence tomography, electroretinography, and histological assays. Overall, there was a 42% and 26% reduction in a-wave and oscillatory potential amplitudes in the electroretinograms respectively, along with a global decrease in retinal thickness, with increased variability. Qualitative inspection also revealed that there were variable levels of retinal degeneration and remodeling both within and between treated eyes, mimicking the disease heterogeneity observed in retinitis pigmentosa. These findings confirm that ATP can be utilized to unilaterally induce blinding in rabbits and, potentially present an ideal model for future cortical recording experiments aimed at optimizing vision restoration strategies.Clinical Relevance- A rapid, unilaterally induced model of retinal degeneration in an animal with low binocular overlap and large eyes will allow for clinically valid recordings of downstream cortical activity following retinal stimulation. Such a model would be highly beneficial for the optimization of clinically appropriate vision restoration approaches.

Effects of Adjuvant and Immunization Route on Antibody Responses against Naja Naja oxiana Venom.

Naja naja oxiana (NNO) is one of the important venomous species in Iran. The current snakebite treatment is antivenom therapy that deals with hyper immunization of horses with crude or fractionated snake venom plus traditional adjuvants, like Freund's adjuvant. For improvement of antivenom production, it has been suggested to use different adjuvant systems or immunization procedures. In this study, humoral immune responses against immunogenic fractions of NNO venom (NNO3 and NNO4) and crude venom have been compared by usage of different adjuvant and immunization routes. Additionally, a new indirect enzyme-linked immunosorbent assay (ELISA) was set up for the detection of specific antivenom antibodies. This study was conducted on six different groups of female Dutch rabbits that were hyperimmunized using crude and fractionated NNO venom, along with Freund's and MF59 adjuvants through subcutaneous or intramuscular route. The immunization was performed four times with 10-day intervals and the levels of specific antibodiees were detected by indirect ELISA. The statistical analysis reveals a negligible variation in the antivenom titers among the venom-inoculated groups, regardless of the adjuvant type or the immunization route. Finally, it was concluded that the fractions are efficient for antivenom production, and it is possible to use MF59 adjuvant via subcutaneous routes as an alternative to Freund's adjuvants considering its fair immunopotentiation capacity and safety in animals.

Histopathological characteristics of larynx in hypothyroidism in an experimental rabbit model.

ObjectiveHypothyroidism has a significant effect on the patients' voices. This study evaluated the histopathological characteristics of larynx following hypothyroidism in an experimental rabbit model.MethodsEleven male Dutch rabbits were included. Methimazole‐induced hypothyroidism was done for nine rabbits. The remaining two rabbits were assigned as controls. Six weeks after starting methimazole, a histological examination was performed with parameters of inflammation, ulceration, hemorrhage, and thickness of epithelium, Reinke's space, vocal ligament, thyroarytenoid muscle, collagen deposition, and periodic acid‐Schiff (PAS)‐positive materials, as well as confirmation of hypothyroidism by T4 measurement.ResultsHistologic examination showed a significant thickening of epithelium, Reinke's space, vocal ligament, and collagen PAS‐positive materials deposition in hypothyroid rabbits (p < .05). There was significant reduction in thyroarytenid muscle thickness (p < .05). Inflammation, ulceration, and bleeding were not significantly different between hypothyroid and control rabbits' laryngeal specimens.ConclusionHypothyroidism causes significant changes in the laryngeal tissues. Thickening of epithelium, Reinke's space, vocal ligament, collagen, PAS‐positive materials, and reduced thickness of thyroarytenoid muscle are the major findings of this study.

Use of Magnetic Resonance Imaging to Assess the Regenerative Effects of Adipose Tissue-Derived Mesenchymal Stem Cells in a Rabbit Cartilaginous Laryngeal Defect Model

BackgroundStenosis and scar formation after repair of laryngeal tissue defects are serious problems that can significantly influence a patient's quality of life.ObjectiveIn this study, we evaluated the use of magnetic resonance imaging to assess the efficacy of adipose tissue-derived mesenchymal stem cells (ASCs) on cartilaginous regeneration in an experimental rabbit model.MethodsTen male white Dutch rabbits each had a 5 mm cartilaginous defect created surgically in the right and left thyroid lamina. On the right side, ASCs labeled with iron oxide particles were infused. As a control, the left side was left untreated. Repair of the defects were then evaluated by direct observation, histological evaluation, and magnetic resonance imaging monitoring done on days 1, 7, 14, and 28.ResultsHistological examination revealed that compared with control, transplanted ASCs significantly increased cartilage regeneration (P ˂ 0.001), reduced inflammation (P ˂ 0.001), and fibrosis (P = 0.050). Magnetic resonance imaging tracking showed accurate placement and viability of the infused ASCs, as evidenced by low signal intensity onT2 weighted images at the level of the right thyroid cartilage.ConclusionsInfusion of ASCs improved laryngeal regeneration of surgically induced cartilaginous defects while decreasing fibrous tissue formation in this in vivo rabbit model. Furthermore, magnetic resonance imaging was shown to be a useful, noninvasive method to track correct ASCs placement and viability in cartilage regeneration in this animal model.

Craniometric Analysis of European Rabbit (Oryctolagus Cuniculus) Breeds to Trace out Intraspecific and Inter Gender Morphometric Variations

The family Liproidae expresses the significant variation of morphometric features at species level. In already available literature on the European rabbit (Oryctolagus cuniculus) the idea is proposed that there can be variation in the morphometric character of different breeds of Oryctolagus cuniculus but there are negligible scientific research base evidences for it. So in this study interbreed craniometric comparison of the European rabbit is carried out to trace out their intergender and intraspecific morphometric variations. The study material consists of 32 sexually mature rabbits belong to two breeds of European rabbit that are New Zealand rabbit (eight males and eight females) and American Dutch rabbit (eight males and eight females) collected from different districts of the Punjab, Pakistan. There were 29 different measurements taken from the skull and mandible of both breeds by using digital and manual verniar calipers. The results of this study have revealed that there is significant interbreed variation in the nasal length measurement of the New Zealand and American Dutch rabbit. This significant interbreed difference in nasal length is observed in both female as well as male rabbits (p=0.0059 and 0.0069 respectively). The current study also depicts that inter gender craniometric variations exist in the New Zealand as well as American Dutch rabbit. The standard deviation of the foramen magnum index of the both included breeds is comparatively higher than all the other included morphometric features. This study provides the baseline data on interbreed craniometric variations in the Oryctolagus cuniculus.

Melanocortin 4 receptor (Mc4r) gene polymorphism and its association with body weights of some breeds of rabbit

In livestock production, traditional methods of selection have always been the way to go. However, with the advent of genomics techniques, methods such as PCR-RFLP is been employed to identify single nucleotide polymorphism of likely candidate genes useful for livestock selection and improvement. Therefore, the aim of this study was to investigate the association of Melanocortin 4 Receptor (MC4R) gene polymorphism with the body weight ofrabbits. Seventy-four rabbits were used for this study consisting of six breeds; 26 Chinchilla, 3 Californian, 11 Dutch, 4 English Spot, 10 New Zealand White and 20 Fauve de Bourgogne (FDB) breeds. Blood samples were collected from the animals with needle and syringe and transferred unto FTA cards and stored away from light. Body weight measurements on the animals were recorded from 2 weeks to 20 weeks. PCR-RFLP analysis produced threegenotypes AA, AG, GG with genotype frequency of 0.14, 0.69 and 0.18 respectively. Allele frequency 0.48 and 0.52 for allele A and G respectively was obtained. Chi-square test showed that the population was not in Hardy-Weinberg equilibrium. Association analysis between the MC4R “c.101G&gt;A” SNP and body weight of rabbit was tested using GLM procedure of SAS programme. Genotype GG had higher body weight (p&lt;0.05) at 12, 16 and 20 weeks inthe Dutch rabbits while genotype AA recorded a higher (p&lt;0.05) body weight value at 12 weeks in New Zealand White rabbits. More so, female Dutch rabbits had higher (p&lt;0.05) mean weight than the males at 12, 16 and 20 weeks of age. Male New Zealand White breeds recorded higher (p&lt;0.05) mean weight than the female animals. The result of the study showed that MC4R “c.101G&gt;A” SNP was not associated with the body weight in the studied rabbit population, although, genotype AA had higher mean weight values at 12, 16 and 20 weeks of age than genotypes AG and GG.

The Healing Effect of Amniotic Membrane in Laryngeal Defects in Rabbit Model.

Fibrosis and scar formation following laryngeal repairing is a major concern. This study evaluated the efficacy of applying amniotic membrane (AM) as a biologic dressing to reduce fibrosis and inflammation and promote cartilage repair. Experimental animal study. Nine male white Dutch rabbits were selected. A standard defect (5 mm) was created in right and left thyroid lamina. In the right side, two layers of AM were applied while the left side was kept intact for future comparison. Histologic examination with criteria of inflammation, fibrosis, and cartilage regeneration was performed 2, 4, and 6 weeks following AM application. All procedures were done according to animal ethics rules. Histologic and gross examination showed that AM application was able to reduce inflammation and fibrosis and improve cartilage regeneration significantly. As a useful intervention, AM application can reduce inflammation and fibrosis and enhance cartilage regeneration, following laryngeal defect repair. NA Laryngoscope, 131:E527-E533, 2021.

Effects of 0.4% ripasudil hydrochloride hydrate on morphological changes in rabbit eyes.

We evaluated the cellular structure changes after continuous use of ripasudil hydrochloride hydrate in rabbit eyes which might affect its own efficacy and adverse effects. Two pigmented Dutch rabbits and 1 Japanese white rabbit were instilled with 0.4% ripasudil hydrochloride hydrate to the left eye twice daily. The right eye was observed as the control. Both eyes of all 3 rabbits were then enucleated for histopathologic examination by light and electron microscope at 1mo in 1 of the pigmented Dutch rabbits, 3mo in the other pigmented Dutch rabbit, and in the Japanese white rabbit after instillation. Microscopic observations showed increase intercellular space in trabecular meshwork, ciliary body, and iris stoma, increase pigmented granule number and size in iris epithelial cells, and decrease actin filament in iris muscle fiber cells. Consequently, ripasudil hydrochloride hydrate decreases the intraocular pressure by improving the conventional outflow and may also facilitate the unconventional outflow via intercellular space widening without serious side effects.

Methionine and Threonine Requirements of Dutch Rabbits Fed under a Cecotrophy Prevention Program

It is suggested that the difference in body size between domestic-type rabbits and small pet-type rabbits results in different nutrient requirements. The nutritional requirements of pet rabbits have been assessed, although such assessments require evaluation throughout the rabbit life span. The present study was conducted under a cecotrophy prevention program with young and adult rabbits. Six male Dutch rabbits were housed individually in a dormitory-type cage, and they were randomly fed graded levels of dietary methionine and threonine, at ratios of 4:0, 3:1, 2:2, 1:3, and 0:4 mixed with two types of feed, 4:0 and 0:4. Four days after switching diets and 4 hrs after starting morning feeding, approximately one milliliter of blood was collected from the vein of the ear. Free amino acid concentrations in the plasma were determined with a high-speed amino acid analyzer. Plasma concentrations of methionine and threonine compared to dietary methionine and threonine levels are shown in young rabbits. The plasma concentration of methionine remained constant at a low level and then increased linearly. The intersection was estimated as 0.16 g/d. In the same manner, the intersection of the plasma threonine value was estimated as 0.27 g/d. These values were calculated as 0.27% and 0.47% of the diets, respectively. In the case of adult rabbits, the baseline was not obtained for dietary methionine and threonine levels. The methionine requirement was estimated as 0.11 g/d. The threonine requirement was estimated as 0.22 g/d. These values were calculated as 0.15% and 0.30% of the diets, respectively. In comparison with young and adult rabbits, both methionine and threonine showed a low baseline level in young rabbits, while their variations in plasma levels of adult rabbits were not determined. The requirement of both amino acids in young rabbits is higher than that in adult rabbits. The dietary values of both amino acids in young rabbits were also higher than those in adult rabbits. Small pet-type adult rabbits required lower amino acid levels than domestic-type rabbits.

Intra-Spinal Stimulation Leads to Activation of Motor Modules and Restoration of Monitored Movements in Spinally-Injured Rabbits

Electrical stimulation of functional units (modules) in an injured spinal cord is the primary strategy to restore neuromuscular movements. The current study aims to evaluate the efficacy of the motor module activation in male Dutch rabbit models with injured spinal cord to mimic monitored movements using intra-spinal stimulation. Leg-angle movements were monitored in three rabbits before and after spinal injury using a digital camera with 40 frames/sec. To obtain the leg-movement model before injury, three movements were considered as monitored movements. Then the rabbits were anesthetized and a T7-L4 laminectomy was performed. After spinal injury, the leg-angle movement was mimicked in the anesthetized rabbits with a custom–made stimulator by scanning the spinal cord to locate the leg-angle movements related motor modules. Subsequently, three stimulating electrodes were fixed on the located modules for restoring monitored movements. Finally, the leg-angle movements were analyzed using paired t-student test. Root mean square tracking error was calculated between normal and mimicked leg-angle movements. Based on our data, a combination intra-spinal stimulation of three motor modules, led to no significant difference in hip, knee and ankle angles as compared to those recorded before induction of injury. The RMS errors were 6.26±1.17o, 6.07±1.20o and 6.70±0.92o for the hip, knee and ankle respectively. Overall RMS for our data was 6.12±1.27o. The detection of motor modules in spinal cord and their stimulation is able to restore the monitored movements with a good tracking performance; thus, it can be used to recover motion patterns in spinally-injured rabbits.

Implantation of multiple suprachoroidal electrode arrays in rabbits

PurposeEpiretinal and subretinal prosthesis have been shown to be a valid way to provide some vision to patients with advanced outer retinal degeneration and profound vision loss. However, the field of vision for these patients is markedly limited by the area occupied by the electrode array. In this study, we aimed to evaluate the feasibility of implantation of multiple suprachoroidal electrode arrays in a single eye in order to increase the field of vision in patients implanted with retinal prosthesis. MethodsThe right eye of seventeen Dutch rabbits (age range, 5–6 months) was used for the study. Multiple inactive custom-made electrode arrays were inserted into the suprachoroidal space (SCS) and animals were followed up for up to 6 months using fundus photography, optical coherence tomography (OCT), and fluorescein angiography (FA). ResultsIt was possible to surgically implant up to 8 electrode arrays in a single eye. None of the rabbits showed any major complications. The electrodes were well tolerated and remained in position in all rabbits. There was no evidence of retinal damage on follow-up exams and FA throughout the study. ConclusionMultiple suprachoroidal electrode array implantation is feasible and may provide a novel approach to increase the field of vision in subjects implanted with retinal prosthesis.

Rebamipide protects against glaucoma eyedrop-induced ocular surface disorders in rabbits.

PurposeThis study aimed to determine if rebamipide eyedrops can improve ocular surface damage caused by the use of glaucoma eyedrops.MethodsFemale Kbl:Dutch rabbits were used to evaluate glaucoma eyedrop-induced ocular surface damage; one eye of each rabbit was untreated and the other was administered glaucoma eyedrops for 30 days. To evaluate the effects of rebamipide on ocular surface damage, one eye of each rabbit was administered vehicle-treated glaucoma eyedrops and the other was administered rebamipide-treated glaucoma eyedrops for 30 days. Corneal and conjunctival epithelial damage was evaluated using fluorescein and rose bengal staining, respectively. Conjunctival inflammation was observed by light microscopy with hematoxylin-eosin staining. Dark cells (in which the corneal microvilli were damaged) were analyzed by scanning electron microscopy.ResultsThere were no significant differences in fluorescein staining between the untreated and glaucoma eyedrop-treated groups; however, rose bengal staining and the number of inflammatory cells in the conjunctiva significantly increased after glaucoma eyedrop treatment. There was a four-fold increase in the number of dark cells in the glaucoma eyedrop-treated group compared to untreated. In contrast, in the conjunctiva of the rebamipide-treated glaucoma eyedrop group, rose bengal staining scores, the number of inflammatory cells, and the number of dark cells were decreased compared to the vehicle-treated glaucoma eyedrop group.ConclusionsResults from our in vivo rabbit study demonstrated that short-term use of glaucoma eyedrops induces corneal epithelium disorders at the cellular level, but that simultaneous use of rebamipide has the potential to protect and repair the ocular surface.

Monitoring immune response after allogeneic transplantation of mesenchymal stem cells for osteochondral repair.

The aim of this study was to investigate the safety of using allogeneic magnetically labelled mesenchymal stem cells (m-MSCs) to ameliorate osteochondral repair, with immune surveillance using a mixed lymphocyte reaction (MLR) assay. Twenty knees of Japanese white rabbits were randomly divided into two groups: the control (autologous) group, where 2×105 autologous m-MSCs were transplanted into the defect site; the experimental (allogeneic) group, where 2×105 m-MSCs from Dutch rabbits were transplanted into the defect of Japanese white rabbits. The rabbits were then euthanized after 12weeks. The repaired tissue was stained with toluidine blue stain in order to produce histological scoring on the Fortier scale. Splenocytes were used to evaluate anti-donor alloreactivity by a MLR assay using the carboxyfluorescein diacetate succimidyl ester (CFSE) labelling technique (CFSE-MLR). In both groups, complete repair of the subchondral bone covered by a layer of chondrogenic tissue was confirmed. Also, there was no histologically significant difference on the Fortier scale. Using the CFSE-MLR assay, CD4+ T-cells showed alloreactivity in each combination, while the stimulation index of CD4+ T-cells was not statistically different between the control and experimental groups. Allogeneic m-MSCs are a safe alternative source to autologous m-MSCs, upholding repair of an osteochondral defect for clinical application using universal donor MSCs through a one-stage surgical procedure. Copyright © 2017 John Wiley & Sons, Ltd.

Effects of ripasudil hydrochloride hydrate (K-115), a Rho-kinase inhibitor, on ocular blood flow and ciliary artery smooth muscle contraction in rabbits

Ripasudil, a Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor, is a novel drug for glaucoma in Japan. ROCK inhibition not only reduces intraocular pressure (IOP) but also increases ocular blood flow. We investigated the effects of ripasudil on optic disc blood flow (ODBF) in rabbit eyes and in isolated rabbit ciliary arteries. We measured IOP by tonometry and ODBF by laser speckle flowgraphy (LSFG) in male Dutch rabbits. A single drop (20μL) of 0.8% ripasudil was delivered to the ocular surface after topical application of phenylephrine hydrochloride to reduce the ODBF. The effects of ripasudil on isolated rabbit ciliary artery smooth muscle contractions were measured in vitro with a myograph. Ripasudil inhibited the reduction of ODBF induced by phenylephrine at 30 and 120min after instillation (P<.05). The blood flow change was not significantly correlated with the IOP change. Ripasudil induced a concentration-dependent relaxation in isolated rabbit ciliary arteries precontracted with a high-potassium solution. This relaxation was not mediated through the endothelium-dependent activities of nitric oxide synthase, prostacyclin, or the large-conductance calcium-activated K+ channel as shown by the inability of specific inhibitors of these pathways to block the ripasudil-induced relaxation. Taken together, our results showed that ripasudil not only decreased IOP but also increased ODBF in rabbits. However, the changes in IOP were not correlated with the changes in ODBF. Ripasudil also induced a concentration-dependent relaxation of isolated rabbit ciliary arteries through a NO-independent mechanism. Further investigation of the effect of ripasudil on ODBF is needed.