Volatile Sulfur Compounds Produced by the Anaerobic Bacteria Porphyromonas spp. Isolated from the Oral Cavities of Dogs.

Porphyromonas spp. are oral anaerobic Gram-negative bacteria that form black-pigmented colonies on blood agar and produce volatile sulfur compounds (VSCs), such as hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide ((CH3)2S), which cause halitosis and the destruction of periodontal tissues. P. gulae is considered the main pathogen involved in periodontal disease in dogs. However, the characteristics of the VSCs produced by P. gulae are unknown. In the present study, VSCs were measured in 26 isolates of P. gulae and some isolates of the other Porphyromonas spp. obtained from the oral cavities of dogs with periodontal disease using an in vitro assay with an Oral ChromaTM gas chromatograph. The results demonstrated that P. gulae was able to produce large amounts of H2S and CH3SH, and the dominant product was CH3SH (CH3SH/H2S was approximately 2.2). Other Porphyromonas spp. that were also obtained from the oral cavities of dogs with periodontal disease indicated similar levels of production of H2S and CH3SH to those of P. gulae. It is strongly suggested that the high levels of H2S and CH3SH produced by P. gulae and other Porphyromonas spp. contribute to halitosis and the destruction of periodontal tissues during the progression of periodontal disease in dogs.

Male pseudohermaphroditism in a complex malformed calf born with an acardius amorphus cotwin-a case report.

BACKGROUND: Male pseudohermaphroditism is a developmental anomaly wherein animals are genetically and gonadally male, but their internal and/or external genitalia resemble those of females. In cattle, pseudohermaphroditism is often accompanied by multiple severe malformations. To the best of our knowledge, this is the first report of male pseudohermaphroditism in a complex malformed calf born with an acardius amorphous cotwin. CASE PRESENTATION: This report describes the case of a three-day-old, male anurous Japanese Black calf born with an acardius amorphous cotwin, complete absence of the tail, agenesis of the anus, separate scrota, and umbilical hernia. Transthoracic echocardiography and computed tomography revealed serious malformations in the skeletal system and the circulatory, digestive, urinary, and genital organs. Necropsy revealed rectal atresia, immature testes, epididymis, and penis, but no male accessory gonads. Histological analyses revealed vaginal- and uterine-like tissues adjacent to or fused to the rectum. Fluorescence in situ hybridization detected X and Y chromosomes, and some cells presented two X-probe signals in the same nucleus. CONCLUSIONS: In contrast to the male genitalia, the female genitalia derived from the Müllerian ducts were difficult to detect by necropsy in the presented case. Many similar cases may be overlooked in clinical practice.

Perception biases for problematic behaviors in dogs due to owners' attributes.

The abnormal or undesirable behaviors of owned dogs are not always considered problematic; it depends on the perception bias of their owners. To demonstrate the perception bias in dog owners' attributes, 133 dog owners in Aomori (rural) and Tokyo (urban) were surveyed through questionnaires distributed via seven animal hospitals regarding the frequency of potentially problematic behaviors and their perceived difficulty with them. The interaction effects of the lived location (urban, rural), age (20s-50s, 60s or later), and sex (male, female) of the owners were evaluated through a hierarchical multiple regression model. The analyses of 115 responses demonstrated that the tendency of perception regarding the five major behaviors under consideration varied with these attributes. Our results indicated that owners living in Aomori undervalued destruction behaviors of their dogs both when family members were and were not at home, while they overvalued jumping on people. Senior owners tended to undervalue nuisance barking when family members were at home along with uncontrollable hyperactivity. Male owners also undervalued destructive behavior when family members were not home. The study concludes that perception bias due to dog owners' attributes should be taken into account in epidemiological surveys and during medical interviews by veterinarians or other behavioral specialists. Further exhaustive investigation and exploration of the cultural background of these perception differences should be conducted.

Dietary olive oil intake induces female-specific hepatic lipid accumulation without metabolic impairment in mice.

Olive oil is one of the most widely researched Mediterranean diet components in both experimental models and clinical studies. However, the relationship between dietary olive oil intake and liver function in a healthy state of the body remains unclear. Because men are at a greater risk of developing hepatic diseases than women, and because hepatic metabolism is regulated by sex hormones, we hypothesized that olive oil-induced changes in hepatic metabolism would differ by sex. To test our hypothesis, 12-week-old C57BL/6JJcl male and female mice were fed an olive oil diet for 4 weeks. Blood was collected and serum biochemical components were analyzed. Hepatic lipid accumulation was determined via histological analysis using Sudan III staining. Finally, transcript expression levels of hepatic metabolism-related genes were analyzed using quantitative polymerase chain reaction. We observed significant increased hepatic lipid droplet accumulation in olive oil-fed female mice. Serum biochemical and liver messenger RNA expression analyses revealed that the hepatic lipid accumulation was nonpathological and did not involve inflammation. Moreover, the expression of genes related to triacylglycerol and fatty acid synthesis (Dgat1, Dgat2, Agpat3, and Fasn) was significantly upregulated in the liver of olive oil-fed female mice compared with control female mice. Our study demonstrates female-specific hepatic lipid accumulation without liver impairment in a dietary olive oil-fed mouse model. These findings provide a deeper mechanistic understanding of sex-dependent hepatic lipid metabolism of dietary oils.

Effects of a Soluble Guanylate Cyclase Stimulator Riociguat on Contractility of Isolated Pulmonary Artery and Hemodynamics of U46619-Induced Pulmonary Hypertension in Dogs.

Soluble guanylate cyclase (sGC) stimulator riociguat is a relatively novel therapeutic agent for pulmonary hypertension (PH) in human medicine. Riociguat induces endothelium-independent pulmonary artery (PA) relaxation by directly activating the sGC-cyclic guanosine-3',5'-monophosphate (cGMP) pathway in muscle cells. Although riociguat may be effective in the treatment of dogs with refractory PH, basic studies on its clinical application in veterinary medicine are lacking. The present study aimed to explore the effects of riociguat on the contractility of an isolated canine PA and the hemodynamics of dogs with acute PH. In an isolated endothelium-denuded canine PA, the effects of riociguat on endothelin (ET)-1-induced contraction and cGMP levels were investigated using the Magnus method and ELISA, respectively. The effect of riociguat on the hemodynamics of the thromboxane A2 analog U46619-induced PH model dog was examined by invasive catheterization. Riociguat increased cGMP levels and reduced ET-1-induced contraction of the isolated PA. Riociguat inhibited the U46619-induced elevation of PA pressure and pulmonary vascular resistance and increased cardiac output, but it had no effect on basal systemic blood pressure. These results demonstrate for the first time that riociguat can inhibit the elevation of PA pressure through PA relaxation via an endothelium-independent increase in cGMP in dogs with PH.

Human Omentin-1 Administration Ameliorates Hypertensive Complications without Affecting Hypertension in Spontaneously Hypertensive Rats.

Hypertension is one of the major risk factors for cardiovascular diseases and is caused by various abnormalities including the contractility of blood vessels. Spontaneously hypertensive rats (SHR), whose systemic blood pressure increases with aging, are a frequently used animal model for investigating essential hypertension and related complications in humans due to the damage of several organs. Human omentin-1 is an adipocytokine consisting of 313 amino acids. Serum omentin-1 levels decreased in hypertensive patients compared with normotensive controls. Furthermore, omentin-1 knockout mice showed elevated blood pressure and impaired endothelial vasodilation. Taken together, we hypothesized that adipocytokine, human omentin-1 may improve the hypertension and its complications including heart and renal failure in the aged SHR (65-68-weeks-old). SHR were subcutaneously administered with human omentin-1 (18 µg/kg/day, 2 weeks). Human omentin-1 had no effect on body weight, heart rate, and systolic blood pressure in SHR. The measurement of isometric contraction revealed that human omentin-1 had no influence on the enhanced vasocontractile or impaired vasodilator responses in the isolated thoracic aorta from SHR. On the other hand, human omentin-1 tended to improve left ventricular diastolic failure and renal failure in SHR. In summary, human omentin-1 tended to improve hypertensive complications (heart and renal failure), while it had no influence on the severe hypertension in the aged SHR. The further study of human omentin-1 may lead to the development of therapeutic agents for hypertensive complications.

Molecular prevalence and zoonotic potential of trichomonads from oral cavities in household dogs.

This study investigated the molecular prevalence of oral trichomonads in household dogs. Of the 144 dogs, 21 (14.6%, 21/144) tested positive for oral trichomonads. The prevalence was significantly higher in dogs with severe gingivitis (gingival index 3: 30.0%, 8/26) than that in normal dogs (gingival index 0: 2.7%, 1/37). Therefore, an interaction between oral trichomonads and the development of periodontal disease is suggested. Of the 21 positive samples, 16 isolates were T. brixi, four isolates were T. tenax, and one was Tetratrichomonas sp. Considering T. tenax is recognized as a zoonotic agent, transmission between dogs and humans cannot be neglected.

Eukaryotic elongation factor 2 kinase inhibitor, A484954 induces diuretic effect via renal vasorelaxation in spontaneously hypertensive rats.

Eukaryotic elongation factor 2 (eEF2) kinase (eEF2K), alternatively known as calmodulin-dependent protein kinase III, inhibits protein translation via phosphorylating its sole substrate, eEF2. We previously demonstrated that expression and activity of eEF2K change in mesenteric artery from spontaneously hypertensive rats (SHR) with aging and that eEF2K is involved in pathogenesis of essential hypertension. In addition, we have recently revealed that acute intravenous injection with A484954, a selective eEF2K inhibitor, lowers blood pressure specifically in SHR partly via inducing vasorelaxation. In this study, we examined whether A484954 induces diuretic effect. After male SHR and normotensive Wistar Kyoto rats (WKY) were given a single intraperitoneal injection of A484954 (2.5 mg/kg, 0.5-9 h), urine was collected using metabolic cage. Contraction of isolated renal arteries form SHR was isometrically measured. While A484954 did not induce diuretic effect in WKY, it increased urine output, water intake, and urinary sodium excretion in SHR. A484954 (10 µM) induced vasorelaxation in isolated renal arteries, which was inhibited by a ß-adrenergic receptor antagonist, propranolol. It was confirmed that A484954 increased renal blood flow in SHR as measured by renal ultrasonography. In summary, it was for the first time revealed that A484954 induces diuretic effect in SHR at least partly via renal vasorelaxation through ß-adrenergic receptor.

Molecular Identification of Encephalitozoon hellem from Companion Birds Kept in Pet Shops, Japan.

To evaluate the role of companion birds as a reservoir of Encephalitozoon hellem infection in humans, the present study determined the prevalence and genotypes of E. hellem from 269 birds in 4 pet shops using polymerase chain reaction (PCR) assay. E. hellem was identified in 4.8% (13/269) of the birds and was detected in all pet shops. Every positive sample corresponded to zoonotic genotype 1A. Considering the low prevalence of E. hellem infection, it is likely that the risk of zoonotic transmission from companion birds kept in pet shops to humans is low in Japan.

Molecular prevalence of trichomonad species from pet shop puppies and kittens in Japan.

Pentatrichomonas hominis and Tritrichomonas foetus (cat genotype) have been commonly identified as intestinal trichomonads in both dogs and cats. Although P. hominis is considered as non-pathogenic protozoa in many kinds of mammals, it has the potential for zoonotic transmission. T. foetus has been recognized as the emerging causative agent of diarrhea in cats without the risk of zoonotic transmission. As pet shops are the major source of young companion animals, the present study discusses the molecular prevalence of P. hominis and T. foetus from 544 pet shop puppies and 409 kittens. The results suggest that the prevalence of P. hominis (puppies: 7.0%; kittens: 0.5%) and T. foetus (puppies: 0%; kittens: 2.4%) in pet shop young animals are low. In addition, the infections of P. hominis and T. foetus are not always associated with the clinical signs (soft or diarrhea feces).

Clinical efficacy of combination therapy of itraconazole and prednisolone for treating effusive feline infectious peritonitis.

A 3-month-old male Scottish Fold kitten with pleural fluid and low ratio of albumin to globulin (A/G ratio) was brought to our small animal hospital. Since RNA from the type I feline coronavirus (FCoV) were detected in drained pleural fluid, the cat was tentatively diagnosed with effusive feline infectious peritonitis (FIP). Following the administration of itraconazole and prednisolone, the A/G ratio increased, and the pleural fluid mostly disappeared. The fecal FCoV levels temporarily decreased. However, the cat showed neurological manifestations and was eventually euthanized due to status epilepticus after 38 days of treatment. In conclusion, itraconazole partly exerted a beneficial effect in a cat with FIP. However, further investigation of a possible role of itraconazole in FIP treatment is warranted.

Acute intracerebroventricular injection of chemerin-9 increases systemic blood pressure through activating sympathetic nerves via CMKLR1 in brain.

Chemerin is an adipocytokine involved in inflammation and lipid metabolism via G protein-coupled receptor, chemokine-like receptor (CMKLR)1. Since the important nuclei regulating pressure (BP) exist in the brain, we examined the effects of acute intracerebroventricular (i.c.v.) injection of chemerin-9 on systemic BP and explored underlying mechanisms. We examined the effects of acute i.c.v. injection of chemerin-9 (10 nmol/head) on systemic BP by a carotid cannulation method in the control or CMKLR1 small interfering (si) RNA-treated Wistar rats (0.04 nmol, 3 days, i.c.v.). We examined protein expression of CMKLR1 around brain ventricles by Western blotting. We examined the effects of acute i.c.v. injection of chemerin-9 on serum adrenaline by a high performance liquid chromatography. In the control siRNA-treated rats, chemerin-9 significantly increased mean BP, which reached a peak at 2 to 4 min after injection. On the other hand, in the CMKLR1 siRNA-treated rats, chemerin-9 did not affect the mean BP. Protein expression of CMKLR1 specifically in subfornical organ (SFO) and paraventricular nucleus (PVN) from the CMKLR1 siRNA-treated rats decreased compared with the control siRNA-treated rats. In the control siRNA-treated rats, chemerin-9 increased serum adrenaline level. On the other hand, in the CMKLR1 siRNA-treated rats, chemerin-9 did not affect the serum adrenaline level. Further, pretreatment with prazosin, an α-adrenaline receptor blocker, significantly prevented the pressor responses induced by chemerin-9. In summary, we for the first time demonstrated that chemerin-9 stimulates the sympathetic nerves via CMKLR1 perhaps expressed in SFO and PVN, which leads to an increase in systemic BP.

A case of canine hypoadrenocorticism needing blood transfusion for severe acute anemia due to gastrointestinal hemorrhage.

A 3-year-old male Rottweiler presented with the chief complaint of recurrent vomiting, diarrhea, hypothermia, and lethargy. Hypovolemic shock was noted with abnormal electrolytes (Na/K ratio, 27.9) and anemia (hematocrit, 17.3%). Since the hematocrit was 49.2% four days earlier when the primary veterinarian examined the dog, acute anemia was diagnosed. Melena was observed on the next day. The general condition and hydration improved with treatment, and an adrenocorticotropic hormone stimulation test identified hypoadrenocorticism. However, the hematocrit decreased further to 9%, necessitating blood transfusion. The cause of severe acute anemia was thought to be gastrointestinal hemorrhage. It should be noted that hypoadrenocorticism can lead to potentially fatal anemia with gastrointestinal tract bleeding, and blood transfusion may be required.

Molecular prevalence of trichomonad species from pet shop puppies and kittens in Japan / Molecular prevalência de espécies trichomonas em filhotes de cães e gatos de pet shop no Japão

Abstract Pentatrichomonas hominis and Tritrichomonas foetus (cat genotype) have been commonly identified as intestinal trichomonads in both dogs and cats. Although P. hominis is considered as non-pathogenic protozoa in many kinds of mammals, it has the potential for zoonotic transmission. T. foetus has been recognized as the emerging causative agent of diarrhea in cats without the risk of zoonotic transmission. As pet shops are the major source of young companion animals, the present study discusses the molecular prevalence of P. hominis and T. foetus from 544 pet shop puppies and 409 kittens. The results suggest that the prevalence of P. hominis (puppies: 7.0%; kittens: 0.5%) and T. foetus (puppies: 0%; kittens: 2.4%) in pet shop young animals are low. In addition, the infections of P. hominis and T. foetus are not always associated with the clinical signs (soft or diarrhea feces).

Resumo Pentatrichomonas hominis e Tritrichomonas foetus (genótipo de gato) têm sido comumente identificados como trichomonas intestinais em cães e gatos. Apesar de P. hominis ser considerado como protozoário não patogênico em muitos tipos de mamíferos, tem potencial para transmissão zoonótica. Enquanto o T. fetus foi reconhecido como o agente causador emergente de diarreia em gatos sem o risco de transmissão zoonótica. Devido às lojas de animais serem as principais fontes de filhotes de animais domésticos, o presente estudo discute a prevalência molecular e/ou o potencial zoonótico de P. hominis e T. foetus em 544 filhotes de cachorro e 409 gatos de "pet shop". Os resultados sugerem que a prevalência de P. hominis (cães: 7,0%; gatos: 0,5%) e T. foetus (cães: 0%; gatos: 2,4%) em animais jovens de "pet shop" é baixa. Além disso, as infecções de P. hominis e T. foetus nem sempre estão associadas aos sinais clínicos (fezes moles ou diarreia).

Molecular Prevalence of Cryptosporidium spp. in Breeding Kennel Dogs.

Cryptosporidium is a common intestinal protozoan that can lead to diarrhea in humans and dogs. The predominant species of infection are C. hominis and C. parvum in humans, and C. canis in dogs. However, C. canis can infect immunocompromised humans. Considering the close contact with humans, dogs have the potential to be reservoirs for human cryptosporidiosis. Breeding kennels are the major supply source of puppies for pet shops. The present study is to determine the molecular prevalence and characteristics of Cryptosporidium spp. found in breeding kennel dogs. A total of 314 fecal samples were collected from young and adult dogs kept in 5 breeding kennels. A polymerase chain reaction targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. To determine the species, the DNA sequences were compared to GenBank data. Overall, 21.0% of the fecal samples were positive for Cryptosporidium spp. infection. Cryptosporidium spp. was detected in all 5 facilities. A sequencing analysis demonstrated that all isolates shared 99-100% similarity with C. canis. The results suggest that Cryptosporidium spp. infection is present at a high-level in breeding kennel dogs. However, because dominant species in this survey was C. canis, the importance of breeding kennel dogs as reservoirs for Cryptosporidium spp. transmission to humans is likely to be low in Japan.

Eukaryotic elongation factor 2 (eEF2) kinase/eEF2 plays protective roles against glucose deprivation-induced cell death in H9c2 cardiomyoblasts.

During the development of cardiac hypertrophy, glucose deprivation (GD) associated with coronary microvascular rarefaction is caused, leading to cardiomyocyte death. Phosphorylation (inactivation) of eukaryotic elongation factor 2 (eEF2) by eEF2 kinase (eEF2K) inhibits protein translation, a highly energy consuming process, which plays protective roles against nutrient deprivation-induced cell death. We previously showed that eEF2 phosphorylation was increased in isolated heart from several cardiac hypertrophy models. In this study, we investigated whether eEF2K/eEF2 mediates the inhibition of cardiomyocyte death under GD condition. In H9c2 rat cardiomyoblasts cultured with serum-free medium, GD significantly augmented eEF2 phosphorylation and signals related to autophagy [increase of microtubule-associated protein 1 light chain 3 (LC3)-II to LC3-I ratio] and apoptosis (cleavage of caspase-3) as determined by Western blotting. GD induced cell death, which was augmented by eEF2K gene knockdown using a small interfering RNA. eEF2K gene knockdown significantly augmented GD-induced cleavage of caspase-3 and apoptotic nuclear condensation as determined by 4', 6-diamidino-2-phenylindole staining. In contrast, eEF2K gene knockdown significantly inhibited GD-induced increase of LC3-II to LC3-I ratio and autophagosome formation as determined by an immunofluorescence staining. An inhibitor of autophagy, 3-methyladenine or bafilomycin A1 significantly augmented GD-induced cleavage of caspase-3. Further, eEF2K gene knockdown significantly inhibited GD-induced phosphorylation of adenosine monophosphate-activated protein kinase (AMPK)α and its downstream substrate, unc-51 like autophagy activating kinase (ULK)1. An inhibitor of AMPK, dorsomorphin significantly inhibited GD-induced increase of LC3-II to LC3-I ratio. In conclusion, we for the first time revealed that eEF2K/eEF2 axis under GD condition mediates the inhibition of apoptotic H9c2 cell death at least in part via promotion of autophagy through AMPKα/ULK1 signaling pathway.

Molecular Prevalence of Cryptosporidium spp. among Companion Birds Kept in Pet Shops in Japan.

Cryptosporidium is the most common protozoan that can infect a wide range of animals, including mammals and birds. Avian Cryptosporidium spp. can cause enteric and respiratory diseases which can be fatal in birds and some species are zoonotic. Companion birds have the potential as reservoir due to their close contact with humans. Pet shops are the major source of companion birds. However, few reports are available regarding Cryptosporidium spp. infection among companion birds kept in pet shops. The present study reports the prevalence and molecular characteristics of Cryptosporidium spp. among companion birds kept in pet shops in Japan. A total of 265 fresh fecal samples were obtained from birds kept in 4 pet shops; these birds belonged to 41 species in 3 bird orders. A nested polymerase chain reaction (PCR) assay targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. A total of 24 samples (9.1%) were positive, and Cryptosporidium spp. were detected from all pet shops. The prevalence of Cryptosporidium spp. in each of the bird orders was 6.5% (10/153) in Psittaciformes, 14.4% (13/90) in Passeriformes, and 4.5% (1/22) in Galliformes. Based on sequence analysis, 13 (54.2%) isolates were classified to C. galli, 8 (33.3%) were avian genotype III, and the remaining 3 (12.5%) were C. baileyi. No infection with zoonotic C. meleagridis and no coinfection with multiple Cryptosporidium spp. and/or genotypes were observed. The zoonotic potential of Cryptosporidium spp. infecting companion birds kept in pet shops in Japan is likely to be low.

Visceral adipose tissue-derived serine protease inhibitor prevents the development of monocrotaline-induced pulmonary arterial hypertension in rats.

Visceral adipose tissue-derived serine protease inhibitor (vaspin), a recently identified adipocytokine, inhibits inflammation, migration, and apoptosis of vascular cells. We have recently demonstrated that chronic administration of vaspin to spontaneously hypertensive rats partly prevents systemic hypertension through inhibiting inflammation and remodeling of vascular wall. Pulmonary arterial (PA) hypertension (PAH) is caused by PA remodeling, contractile dysfunction, and inflammatory responses. We tested the hypothesis that vaspin could prevent development of PAH in animal model. PAH was induced by a single intraperitoneal injection of monocrotaline (MCT; 60 mg/kg), and vaspin (1 µg/kg/day) was treated for 14 days from the day of MCT injection. PA pressure and contractile reactivity of isolated intrapulmonary artery (IPA) were measured. Using isolated lung tissues, IPA wall thickness and fibrosis, matrix metalloproteinase (MMP) activity, and reactive oxygen species (ROS) generation were examined. For in vitro study, after rat PA smooth muscle cells (PASMCs) were stimulated with interleukin (IL)-1ß (10 ng/ml, 48 h) in the presence of vaspin (5 ng/ml, 30 min), MMP activity and ROS generation were examined. Vaspin significantly attenuated MCT-induced rise in PA pressure, while it had no influence on impairment of relaxing function in IPA. Vaspin significantly prevented MCT-induced IPA fibrosis but not hypertrophy. Vaspin significantly inhibited MCT-induced ROS generation and MMP-2 activation in lung tissues. In addition, vaspin significantly inhibited IL-1ß-induced ROS generation and MMP-2 activation in PASMCs. In summary, we for the first time demonstrate that vaspin prevents MCT-induced PAH at least in part via inhibiting ROS/MMP-2/fibrosis pathway.

Coordination of changes in expression and phosphorylation of eukaryotic elongation factor 2 (eEF2) and eEF2 kinase in hypertrophied cardiomyocytes.

Eukaryotic elongation factor 2 (eEF2) kinase (eEF2K) is one of the Ca2+/calmodulin-dependent protein kinases. Activated eEF2K phosphorylates its specific substrate, eEF2, which results in inhibition of protein translation. We have recently shown that protein expression of eEF2K was specifically increased in hypertrophied left ventricles (LV) from spontaneously hypertensive rats (SHR). However, phosphorylation state of eEF2K and eEF2 in hypertrophied LV is not determined. In the present study, we examined expression and phosphorylation of eEF2K and eEF2 in LV from SHR as well as the pressure overload (transverse aortic constriction: TAC)- and isoproterenol (ISO)-induced cardiac hypertrophy model. In LV from TAC mice, eEF2K expression was increased as determined by Western blotting. In LV from TAC mice and SHR, eEF2K phosphorylation at Ser366 (inactive site) was decreased. Consistently, eEF2 phosphorylation at Thr56 was increased. In LV from ISO rats, while eEF2K phosphorylation was decreased, eEF2K expression and eEF2 phosphorylation were not different as determined by Western blotting. In the results obtained from immunohistochemistry, however, total eEF2K and phosphorylated eEF2 (at Thr56) localized to cardiomyocytes were increased in LV cardiomyocytes from ISO rats. Accordingly, the increased expression and the decreased phosphorylation of eEF2K and the increased phosphorylation of eEF2 in hypertrophied LV were common to all models in this study. The present results thus suggest that cardiac hypertrophy may be regulated at least partly via eEF2K-eEF2 signaling pathway.