Effects of aging and reproductive history on bone parameters of common marmoset (Callithrix jacchus) mandibles.

To understand effects of aging and reproductive history in the bones of common marmosets (Callithrix jacchus), mandibles from 79 males and 66 females were analyzed. Dry bone specimen was prepared from dissected mandible, and analyzed using a dual-energy x-ray absorptiometry (DXA) measurement system in terms of bone weight (BnW), bone area (AREA), bone mineral content (BMC), bone mineral density (BMD, ratio of BMC to AREA) and bone mineral ratio (BMR, ratio of BMC to BnW). The mandible bones became porous and thicker with age.

Effects of aging and delivery order on the breeding capacity of F344/N rats.

Reproductive performance affects the efficiency of the production of animals. Therefore, knowing the reproductive properties of each species or strain of animal is important for proper management of breeding stocks. To elucidate the reproductive properties of female F344/N rats, frequently used for longevity and gerontology research, we monitored the breeding duration, number of deliveries, litter size and weaning rate of their pups.

Strategies for Highly Efficient Rabbit Sperm Cryopreservation.

The rabbit is a valuable animal for both the economy and biomedical sciences. Sperm cryopreservation is one of the most efficient ways to preserve rabbit strains because it is easy to collect ejaculate repeatedly from a single male and inseminate artificially into multiple females. During the cooling, freezing and thawing process of sperms, the plasma membrane, cytoplasm and genome structures could be damaged by osmotic stress, cold shock, intracellular ice crystal formation, and excessive production of reactive oxygen species.

Small-volume vitrification and rapid warming yield high survivals of one-cell rat embryos in cryotubes†.

To cryopreserve cells, it is essential to avoid intracellular ice formation during cooling and warming. One way to achieve this is to convert the water inside the cells into a non-crystalline glass. It is currently believed that to accomplish this vitrification, the cells must be suspended in a very high concentration (20-40%) of a glass-inducing solute, and subsequently cooled very rapidly.

Whole-body insulin resistance and energy expenditure indices, serum lipids, and skeletal muscle metabolome in a state of lipoprotein lipase overexpression.

Introduction: Overexpression of lipoprotein lipase (LPL) protects against high-fat-diet (HFD)-induced obesity and insulin resistance in transgenic rabbits; however, the molecular mechanisms remain unclear. Skeletal muscle is a major organ responsible for insulin-stimulated glucose uptake and energy expenditure.

Objectives: The main purpose of the current study was to examine the effects of the overexpression of LPL on the skeletal muscle metabolomic profiles to test our hypothesis that the mitochondrial oxidative metabolism would be activated in the skeletal muscle of LPL transgenic rabbits and that the higher mitochondrial oxidative metabolism activity would confer better phenotypic metabolic outcomes.

Candidate genes involved in the defunctionalization and refunctionalization of the urinary bladder induced by bladder anuria and reperfusion.

Aims: We develop a novel rabbit urinary diversion model of bladder defunctionalization due to bladder anuria followed by refunctionalization due to urine reperfusion to investigate the molecular biological background. To validate the results, we used reverse transcription-polymerase chain reaction (RT-PCR) to analyze human specimens from defunctionalized bladders in patients receiving dialysis before kidney transplantation.

Methods: Female rabbits were divided into three groups: control, defunctionalized, and refunctionalized.

Endothelial Lipase Exerts its Anti-Atherogenic Effect through Increased Catabolism of β-VLDLs.

Aim: Endothelial lipase (EL) plays an important role in lipoprotein metabolism. Our recent study showed that increased hepatic expression of EL attenuates diet-induced hypercholesterolemia, thus subsequently reducing atherosclerosis in transgenic (Tg) rabbits. However, it is yet to be determined whether increased EL activity itself per se is anti-atherogenic or whether the anti-atherogenic effect of EL is exclusively dependent on its lipid-lowering effect.

Macrophage-derived MMP-9 enhances the progression of atherosclerotic lesions and vascular calcification in transgenic rabbits.

Matrix metalloproteinase-9 (MMP-9), or gelatinase B, has been hypothesized to be involved in the progression of atherosclerosis. In the arterial wall, accumulated macrophages secrete considerable amounts of MMP-9 but its pathophysiological functions in atherosclerosis have not been fully elucidated. To examine the hypothesis that macrophage-derived MMP-9 may affect atherosclerosis, we created MMP-9 transgenic (Tg) rabbits to overexpress the rabbit MMP-9 gene under the control of the scavenger receptor A enhancer/promoter and examined their susceptibility to cholesterol diet-induced atherosclerosis.

Characteristic features of newly established specific pathogen-free albino large rabbit (JW-AKT): Comparison with Japanese White and New Zealand White rabbits.

The present study was conducted to reveal characteristic features of albino large rabbit (JW-AKT) which we formerly established a specific pathogen-free (SPF) colony. Body weights of JW-AKT rabbit at 52 weeks old was 5.7 ± 0.

Age-dependent changes of the mandible bone throughout the lifespan in female F344/N rat.

Age-dependent changes of the mandible bone in female F344/N rats, aged 22-1196 days, were analyzed using physiological bone properties and morphology. Bone weight, bone area, bone mineral components, and bone mineral density were assessed using dual-energy X-ray absorptiometry. The bone weight, bone area, bone mineral components, and bone mineral density increased rapidly until approximately 150 days of age, increased gradually thereafter, and then stabilized or decreased after 910 days of age.

Vitrification of one-cell mouse embryos in cryotubes.

Preventing intracellular ice formation is essential to cryopreserve cells. Prevention can be achieved by converting cell water into a non-crystalline glass, that is, to vitrify. The prevailing belief is that to achieve vitrification, cells must be suspended in a solution containing a high concentration of glass-inducing solutes and cooled rapidly.

Increased Hepatic Expression of Endothelial Lipase Inhibits Cholesterol Diet-Induced Hypercholesterolemia and Atherosclerosis in Transgenic Rabbits.

Objective: Endothelial lipase (EL) is a key determinant in plasma high-density lipoprotein-cholesterol. However, functional roles of EL on the development of atherosclerosis have not been clarified. We investigated whether hepatic expression of EL affects plasma lipoprotein metabolism and cholesterol diet-induced atherosclerosis.

Motility and fertility of rabbit sperm cryopreserved using soybean lecithin as an alternative to egg yolk.

This study was conducted to investigate whether soy lecithin can be used as an alternative cryoprotectant to establish a procedure that does not require the use of egg yolk to cryopreserve rabbit strains. Semen from Japanese White rabbits was frozen with HEPES extender containing 20% egg yolk (EYH), 0.5% (Lec-0.

Effects of type III antifreeze protein on sperm and embryo cryopreservation in rabbit.

We investigated the effects of antifreeze protein (AFP) III supplementation on the cryopreservation of rabbit sperm cells and embryos. Ejaculated semen was collected from male Japanese white (JW) rabbits and divided into four AFP-supplemented groups (0.1 μg/ml, 1 μg/ml, 10 μg/ml, 100 μg/ml) and one control group with no AFP-supplementation.

Effects of cholesterol-loaded cyclodextrins on the rate and the quality of motility in frozen and thawed rabbit sperm.

The motility of sperm after freezing and thawing is critical for effective cryopreservation. It is known that supplementation with cholesterol-loaded cyclodextrin (CLC) improves cryosurvival of sperm in various animals. To clarify the effects of supplementation with CLC on rabbit sperm motility after freezing and thawing, rabbit sperm motility was analyzed using a computer-assisted sperm analysis system.

Populations of follicles in F344/N rats during aging.

Follicular populations were investigated in female F344/N rats to better understand the aging process of the rat ovary. Ovaries dissected at various ages (spanning 1-36 months old) were submitted for histological examination. The total number of primordial, growing (primary and secondary), tertiary, and atretic follicles as well as corpora lutea (CL) were counted in hematoxylin-eosin- and azocarmine-aniline-blue-stained ovarian sections.

Human apolipoprotein A-II protects against diet-induced atherosclerosis in transgenic rabbits.

Objective: Apolipoprotein (apo) A-II is the second major apo of high-density lipoproteins, yet its pathophysiological roles in the development of atherosclerosis remain unknown. We aimed to examine whether apo A-II plays any role in atherogenesis and, if so, to elucidate the mechanism involved.

Methods And Results: We compared the susceptibility of human apo A-II transgenic (Tg) rabbits to cholesterol diet-induced atherosclerosis with non-Tg littermate rabbits.

Life span of common marmoset (Callithrix jacchus) at CLEA Japan breeding colony.

The life span and survival parameters of the common marmoset (Callithrix jacchus) in a breeding colony at CLEA Japan, Inc. were investigated. The average life span of male marmosets was 148.

Endothelial lipase mediates HDL levels in normal and hyperlipidemic rabbits.

Aim: Existing evidence suggests that endothelial lipase (EL) plays an important role in high-densitylipoprotein (HDL) metabolism. Because rabbits are a useful animal model for the study of human lipid metabolism and atherosclerosis, we characterized rabbit EL (rEL) expression and investigated its relationship with plasma HDL levels in normal and hyperlipidemic rabbits.

Methods: We cloned the rEL cDNA and analyzed the EL tissue expression using Northern blotting, real-time RT-PCR, Western blotting, and in situ hybridization.

Bone mineral analysis through dual energy X-ray absorptiometry in laboratory animals.

To determine how to eliminate species difference in animal bone experiment, bone mineral content (BMC) was measured using dual energy X-ray absorptiometry (DXA) on the femurs of laboratory mice (Mus musculus) and rats (Rattus norvegicus), and common marmosets (Callithrix jacchus). Measures were taken on femurs in situ, detached from the body, skinned and defleshed, or dried completely. When the BMC of the bone measured in the intact limb attached to the trunk was set at 100%, the actual BMC of the dry bone was 58.

Human C-reactive protein does not promote atherosclerosis in transgenic rabbits.

Background: Although there is a statistically significant association between modestly raised baseline plasma C-reactive protein (CRP) values and future cardiovascular events, the debate is still unsettled in regard to whether CRP plays a causal role in the pathogenesis of atherosclerosis.

Methods And Results: We generated 2 lines of transgenic (Tg) rabbits expressing human CRP (hCRP). The plasma levels of hCRP in hCRP-Tg-1 and hCRP-Tg-2 rabbits were 0.

Expression of human apoAII in transgenic rabbits leads to dyslipidemia: a new model for combined hyperlipidemia.

Objective: Apolipoprotein AII (apoAII) is the second major apolipoprotein in high-density lipoprotein (HDL). However, the physiological functions of apoAII in lipoprotein metabolism have not been fully elucidated.

Methods And Results: We generated human apoAII transgenic (Tg) rabbits, a species that normally does not have an endogenous apoAII gene.

Aging change of mandibular condyle in female F344/N rat.

To ascertain whether laboratory rats represent an adequate animal model for aging oral cavity research, this study focused on the morphology of the mandibular condyle. Aging changes of cartilaginous conformation and shape of the mandibular condyles were analyzed in female F344/N rats. In the condylar cartilage, articular, proliferative cell and hypertrophic cell layers were observed in 1-month-old (M) rat, whereas flattened cell layer was notable at 2M.

Body and major organ weights of A/J-Chr 11(SM) consomic mice.

The body and major organ weights of A/J-Chr 11(SM) consomic mice were compared to those of the progenitor strains, A/J and SM/J. The weights of the body and organs, except for those of the brain and uterus, were significantly greater in A/J mice than in SM/J mice. However, those of consomic mice were highly variable.