Latest Volume/Issue

Volume And Issue List
Journal of Equine Science
- Vol.28(2017)
  - No.2 p.31-
  - No.1 p.1-
- Vol.27(2016)
- Vol.26(2015)
- Vol.25(2014)
- Vol.24(2013)
- Vol.23(2012)
- Vol.22(2011)
- Vol.21(2010)
- Vol.20(2009)
- Vol.19(2008)
- Vol.18(2007)
- Vol.17(2006)
- Vol.16(2005)
- Vol.15(2004)
- Vol.14(2003)
- Vol.13(2002)
- Vol.12(2001)
- Vol.11(2000)
- Vol.10(1999)
- Vol.9(1998)
- Vol.8(1997)
- Vol.7(1996)
- Vol.6(1995)
- Vol.5(1994)

Predecessor

Experimental Reports of Equine Health Laboratory

Bulletin of Equine Research Institute

Japanese Journal of Equine Science

Journal of Equine Science Vol. 28(2017) No. 2

Full Paper

Does the injection of platelet-rich plasma induce changes in the gene expression and morphology of intact Thoroughbred skeletal muscle?

Kentaro FUKUDA, Hirofumi MIYATA, Atsutoshi KUWANO, Taisuke KURODA, Norihisa TAMURA, Yasumitsu KOTOYORI, Yoshinori KASASHIMA

Released: July 06, 2017

p.31-39

Platelet-rich plasma (PRP) therapy is promising for treating skeletal muscle injuries in human athletes by promoting muscle regeneration. It might also be useful for treating muscle injuries in equine athletes. In the present study, muscle regeneration induced by injection of PRP into intact muscle of Thoroughbred was investigated. Autologous PRP and saline were injected twice into intact left and right gluteus medius muscles of seven clinically healthy Thoroughbreds. Muscle samples were collected from the injection sites by needle biopsy at 2 and 7 days after PRP injection. Immunohistochemical staining to identify the types of myosin heavy chains (MHCs) and satellite cells was performed to compare morphological changes among intact (pre-injection), saline-, and PRP-injected muscles. The expression of marker genes related to muscle regeneration (MHC-I, MHC-II, and embryonic MHC [MHC-e]), satellite cell activity (CK, Pax7, MyoD, and myogenin), and proinflammatory and promyogenic cytokines (IL-6, IGF-1, and HGF) was analyzed and compared between saline- and PRP-injected muscles. There were no obvious morphological differences among the three treatments. There were no significant differences in gene expression associated with satellite cell activity between saline and PRP injection at 7 days after injection. MHC genes showed significantly higher expression levels with PRP than with saline, including MHC-e at 2 days and MHC-I at 7 days after injection. It is suggested that injection of PRP into intact skeletal muscle does not induce specific morphological changes, but upregulate the expression of genes related to muscle regeneration.

Hypoxic training increases maximal oxygen consumption in Thoroughbred horses well-trained in normoxia

Hajime OHMURA, Kazutaka MUKAI, Yuji TAKAHASHI, Toshiyuki TAKAHASHI, James H. JONES

Released: July 06, 2017

p.41-45

Hypoxic training is effective for improving athletic performance in humans. It increases maximal oxygen consumption (V̇O₂max) more than normoxic training in untrained horses. However, the effects of hypoxic training on well-trained horses are unclear. We measured the effects of hypoxic training on V̇O₂max of 5 well-trained horses in which V̇O₂max had not increased over 3 consecutive weeks of supramaximal treadmill training in normoxia which was performed twice a week. The horses trained with hypoxia (15% inspired O₂) twice a week. Cardiorespiratory valuables were analyzed with analysis of variance between before and after 3 weeks of hypoxic training. Mass-specific V̇O₂max increased after 3 weeks of hypoxic training (178 ± 10 vs. 194 ± 12.3 ml O₂ (STPD)/(kg × min), P<0.05) even though all-out training in normoxia had not increased V̇O₂max. Absolute V̇O₂max also increased after hypoxic training (86.6 ± 6.2 vs. 93.6 ± 6.6 l O₂ (STPD)/min, P<0.05). Total running distance after hypoxic training increased 12% compared to that before hypoxic training; however, the difference was not significant. There were no significant differences between pre- and post-hypoxic training for end-run plasma lactate concentrations or packed cell volumes. Hypoxic training may increase V̇O₂max even though it is not increased by normoxic training in well-trained horses, at least for the durations of time evaluated in this study. Training while breathing hypoxic gas may have the potential to enhance normoxic performance of Thoroughbred horses.

Aborted fetal sizes of Thoroughbred horses in Hidaka, Japan, between 2005 and 2015

Harutaka MURASE, Masaki MIYAZAWA, Takehiro HARADA, Midori OZAWA, Fumio SATO, Tetsuro HADA

Released: July 06, 2017

p.47-53

The degree of fetal growth restriction has been unclear in equine reproduction. In this study, 2,195 fetuses from 2,137 abortions during 11 seasons were examined to determine the causes of abortion, and fetal size dimensions (crown rump length and body weight) were measured. In total, 900 cases (42.1%) of abortion were identified as caused by viral infection (215, 10.1%), bacterial infection (156, 7.3%), fungal infection (25, 1.2%), circulation failure (406, 19.0%), multiple causes (66, 3.1%), deformity (13, 0.6%), placental abnormality (12, 0.6%), and other causes (7, 0.3%). All viral infections originated from equine herpes virus. Of all abortions, 94.3% occurred between 181–360 days of pregnancy, and the gestational ages at abortion were different based on the causes. Fetal sizes in viral abortions were considerably larger than those due to other reasons. Compared with viral infection, the crown rump length size dimension of fetuses aborted from multiple and fungal infection was affected. In addition, bacterial infection, circulation failure, and unknown causes of abortions also contributed to growth restriction in terms of body weight. In conclusion, the present study showed details of equine abortion and the relationships between causes of abortion and fetal size. Most of the aborted fetuses showed restrictions in their growth. The manifestations of growth restriction were more related to weight than skeletal length.

Association between exercise-induced pulmonary hemorrhage and inflammatory airway disease in polo ponies

Katia Moreira da SILVA, Juliana Nabuco Pereira OTAKA, Carlos Alexandre Paula GONÇALVES, Estevão Grossi Aguiar SILVA, Nayro Xavier de ALENCAR, Daniel Augusto Barroso LESSA

Released: July 06, 2017

p.55-59

The respiratory system is essential for health and high athletic performance in horses. Respiratory diseases have been recognized as having a major impact on training equine animals and are commonly cited as the second most common cause of wasted training time. Inflammatory airway disease (IAD) is an important cause of poor performance in young racehorses. Exercise-induced pulmonary hemorrhage (EIPH) is considered a major issue for the equine industry because of its high prevalence and association with reduced athletic performance. In Brazil, polo is a growing equestrian sport, but studies on it are still scarce. The aim of this study was to evaluate the occurrence of EIPH, the association between EIPH and IAD, and EIPH influence on the tracheal cytological profile of polo ponies. Thirty-seven horses regularly used for polo were included in this study. Endoscopic examination was performed every 30 to 90 min after practice, and tracheal lavage was performed after 18 to 24 hr. Sixteen animals (43.2%) presented a score of 0 for mucus in endoscopy; twelve animals (32.4%) presented a score for 1 and nine animals (24.3%) presented score 2 of mucus. IAD was characterized by tracheal cytology in 12 animals (32.4%). The occurrence of EIPH in this study was 29.7% (11/37). No significant difference was found in the cell types in tracheal cytology when EIPH-positive and EIPH-negative horses were compared. Polo ponies are affected by IAD and EIPH in relevant proportions, but there was no association between EIPH and tracheal cytological profile.

Note

Evaluating the potential roles of the Gray and Extension loci in the coat coloration of Thoroughbred racing horses

Takahiro SAKAMOTO, Jeffrey A. FAWCETT, Hideki INNAN

Released: July 06, 2017

p.61-65

Horses have substantial variation in coat color, and the genetic loci responsible for the coat color variations have been well investigated. It has been believed that some color variations should follow a single-locus Mendelian law. Examples include the Gray locus that causes the gray phenotype and the Extension locus that specifies the chestnut phenotype. We reevaluated the roles of the Gray and Extension loci by using a large number of mating records of Thoroughbred racing horses. We showed that the data indeed fits the Mendelian law extremely well for the two loci. Furthermore, we demonstrated that the Extension and Agouti loci might have an additional role in determining the degree of melanin that should distinguish bay, dark bay, and brown.

1 - 5 / 5 Articles.

Top of this Page

System Maintenance

J-STAGE will be temporary out of service due to system maintenance on Aug. 26, 1:00 - 6:00 UTC.

Details

Announcement From J-STAGE

July 31, 2017
Due to the end of the Yahoo!JAPAN OpenID service, My J-STAGE will end the support of　the following sign-in services with OpenID on August 26, 2017:
　-Sign-in with Yahoo!JAPAN ID
　-Sign-in with livedoor ID
　* After that, please sign-in with My J-STAGE ID.

July 03, 2017
There had been a service stop from Jul 2‚ 2017‚ 8:06 to Jul 2‚ 2017‚ 19:12(JST) (Jul 1‚ 2017‚ 23:06 to Jul 2‚ 2017‚ 10:12(UTC)) .
The service has been back to normal.We apologize for any inconvenience this may cause you.

May 18, 2016
We have released “J-STAGE BETA site”.

May 01, 2015
Please note the "spoofing mail" that pretends to be J-STAGE.

Back Issues

Volume And Issue List
Journal of Equine Science

Predecessor

Journal of Equine Science Vol. 28(2017) No. 2

Full Paper

Does the injection of platelet-rich plasma induce changes in the gene expression and morphology of intact Thoroughbred skeletal muscle?

Hypoxic training increases maximal oxygen consumption in Thoroughbred horses well-trained in normoxia

Aborted fetal sizes of Thoroughbred horses in Hidaka, Japan, between 2005 and 2015

Association between exercise-induced pulmonary hemorrhage and inflammatory airway disease in polo ponies

Note

Evaluating the potential roles of the Gray and Extension loci in the coat coloration of Thoroughbred racing horses

System Maintenance

Announcement From J-STAGE

Journal Tools

Share this Title

Volume And Issue List Journal of Equine Science

Predecessor

Journal of Equine Science Vol. 28(2017) No. 2

Full Paper

Does the injection of platelet-rich plasma induce changes in the gene expression and morphology of intact Thoroughbred skeletal muscle?

Hypoxic training increases maximal oxygen consumption in Thoroughbred horses well-trained in normoxia

Aborted fetal sizes of Thoroughbred horses in Hidaka, Japan, between 2005 and 2015

Association between exercise-induced pulmonary hemorrhage and inflammatory airway disease in polo ponies

Note

Evaluating the potential roles of the Gray and Extension loci in the coat coloration of Thoroughbred racing horses

System Maintenance

Announcement From J-STAGE

Journal Tools

Share this Title

Volume And Issue List
Journal of Equine Science