ニワトリの不整脈に関する心電図学的研究 : ロードアイランドレッド種の実験的ビタミンB_1欠乏における心電図の変化  [in Japanese] Electrocardiographic Study of Arrhythmias in Chickens : Electrocardiographic Changes Induced by Vitamin B_1 Deficiency in Rhode Island Red Chickens  [in Japanese]

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Author(s)

    • 向井 真 MUKAI Shin
    • 東京農工大学農学部獣医学科家畜病理学教室 Department of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
    • 町田 登 MACHIDA Noboru
    • 東京農工大学農学部獣医学科家畜病理学教室 Department of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
    • 西村 昌晃 [他] NISHIMURA Masaaki
    • 東京農工大学農学部獣医学科家畜病理学教室 Department of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
    • 中村 孝 NAKAMURA Takashi
    • 東京農工大学農学部獣医学科家畜病理学教室 Department of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
    • 桐生 啓治 KIRYU Keiji
    • 東京農工大学農学部獣医学科家畜病理学教室 Department of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology

Abstract

我々はこれまでにニワトリにおいて,心房性および心室性期外収縮を中心とする自然発生性不整脈に関して,ロードアイランドレッド種(RIR)が他の鶏種に比べて有意に高い発生率を示すことを見いだした。一方,各種動物においてビタミンB<SUB>1</SUB>(VB<SUB>1</SUB>)欠乏の際には不整脈の発生が見られることが知られている。また,RIRは他の鶏種と比べてVB<SUB>1</SUB>欠乏に対する感受性が高いとされていることから,RIRにおける不整脈の好発性がRIRのVB<SUB>1</SUB>欠乏に対する高感受性に関わっているか否かを検討する目的で,孵化後30日のRIRと白色レグホン種(WL)の雛20羽ずつにVB<SUB>1</SUB>欠乏飼料を,対照群としてそれぞれ10羽にVB<SUB>1</SUB>含有配合飼料を与え,その際に発生する不整脈について17日間にわたって詳細な心電図学的検索を行った。実験期間中,RIR,WLともに対照群の心拍数は約450/分でほぼ一定しており,不整脈および心電図波形の異常は全く認められなかった。一方,VB<SUB>1</SUB>欠乏群の心拍数は漸次低下する傾向を示した。そして,RIR8羽およびWL4羽に4種類の不整脈が見出され[洞性徐脈(RIR:2羽;WL:3羽),洞房ブロック(1;0),洞停止(3;0),洞性不整脈(2;1)],さらにRJR,WLそれぞれ6羽に心電図波形の異常が認められた[T波の変形(5;3),S-Tの上昇あるいは下降(1;3)]。これらの不整脈および心電図波形の異常の発生率についてVB<SUB>1</SUB>欠乏群は対照群よりも有意に高かったが(p<0.001),VB<SUB>1</SUB>欠乏群のRIRとWLの間に有意な差は認められなかった。<BR>以上の結果から,RIRにおける不整脈の好発性には,RIRのVB<SUB>1</SUB>欠乏に対する高感受性が直接関わっていた可能性は低いものと考えられた。

The Rhode Island Red (RIR) shows a significantly higher incidence of spontaneously occurring arrhythmia due to atrial and ventricular premature depolarization compared with other breeds of chickens as evidenced by our previous study. It has been reported that arrhythmia develops from vitamin B<SUB>1</SUB> (thiamine) deficiency in various animals and that RIR is more susceptible to thiamine deficiency than other breeds of chickens. This study was therefore carried out to investigate the relationship between the higher incidence of arrhythmia in RIR and the higher susceptibility of RIR to thiamine deficiency. Thirty young RIR and 30 young White Leghorns (WL), aged 30 days after hatching, were used for experiments in the study. For both the RIR and the WL, one group consisting of 20 chicks was raised on thiamine-deficient rations as a special diet and another consisting of 10 chicks as normal controls was raised on a conventional diet containing sufficient thiamine; thus the chicks were divided into 4 groups for this experiment. Electrocardiographic examinations were performed during the observation period of 17 day to investigate the occurrence of arrhythmia. In contrast with the findings that the control RIR and WL exhibited stable heart rates of approximately 450/min and neither arrhythmia nor alternated ECG amplitude, electrocardiographic abnormalities were noted in both the groups of VB<SUB>1</SUB>-deficient RIR and WL. Moreover, the heart rate tended to decrease gradually during the course of the study in both VB<SUB>1</SUB>-deficient groups. Five types of arrhythmia were observed in RIR (8 cases) and WL (4 cases) as follows : sinus bradycardia (RIR : 2 ; WL : 3), sinoatrial exit block (1 ; 0), sinus arrest (3 ; 0), sinus arrhythmia (2 ; 1) . In addition, ECGs showing alternated amplitudes were observed in RIR (6 cases) and WL (6 cases) as follows : T wave abnormality (5 ; 3), elevation and depression of S-T segments (1 ; 3) . The VB<SUB>1</SUB>-deficient groups showed significantly higher percentages of occurrence of arrhythmia and alternated EGG amplitude (p<0.001) . There was no significant difference in the percentage of occurrence or arrhythmia and/or alternated ECG amplitude between the two VB<SUB>1</SUB>-deficient groups.<BR>In conclusion, it seems unlikey that the higher incidence of arrhythmia in RIR found in our previous study is directly related to their higher sensitivity to VB<SUB>1</SUB> deficiency.

Journal

  • Advances in Animal Cardiology

    Advances in Animal Cardiology 29(1), 1-7, 1996-06

    Japanese Society of Veterinary Cardiology

References:  15

Codes

  • NII Article ID (NAID)
    10008286904
  • NII NACSIS-CAT ID (NCID)
    AN10192925
  • Text Lang
    JPN
  • Article Type
    ART
  • ISSN
    09106537
  • NDL Article ID
    3995997
  • NDL Source Classification
    ZR22(科学技術--農林水産--畜産)
  • NDL Call No.
    Z18-1508
  • Data Source
    CJP  NDL  J-STAGE  JASI 
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