Title 重輓馬における妊娠異常の新規診断法確立ならびに新生子代謝異常の評価に関する研究( 要約版(Digest) ) Author(s) 木村, 優希 Report No.(Doctoral Degree) 博士(獣医学) 甲第517号 Issue Date 2018-09-21 Type 博士論文 Version none URL http://hdl.handle.net/20.500.12099/77278 ※この資料の著作権は、各資料の著者・学協会・出版社等に帰属します。
Ꮫ ㄽ ᩥ せ ⣙ Ặ ྡ ᮌ ᮧ ඃ ᕼ 㢟 ┠ 㔜㍛㤿࠾ࡅࡿዷፎ␗ᖖࡢ᪂つデ᩿ἲ☜❧࡞ࡽࡧ᪂⏕Ꮚ௦ㅰ␗ᖖࡢ ホ౯㛵ࡍࡿ◊✲ ࣐࢘ࡣ11 ࣧ᭶ࡢ㛗࠸ዷፎᮇ㛫ࢆ⤒࡚ศፔ⮳ࡿື≀࡛࠶ࡿࡀ㸪᪩ᮇ⬇Ṛ⁛㸪ᖏ㌿㸪 ୖ⾜ᛶ⫾┙⅖㸦Ascending Placentitis㸸AP㸧࡞ࡼࡾ㸪ศፔࡲ࡛ዷፎࢆ⥔ᣢ࡛ࡁ࡞࠸ࡇ ࡀከ࠸ࠋࡋࡋ㸪࣐࢘ࡣᏘ⠇⦾Ṫື≀࡛࠶ࡿࡓࡵ㸪ዷፎ႙ኻࡀ㉳ࡇࡗࡓሙྜ㸪ḟࡢ⦾Ṫࢩ ࣮ࢬࣥࡲ࡛㓄ࡍࡿࡇࡣྍ⬟࡛࠶ࡿࠋࡉࡽ㸪ศፔࡲ࡛ዷፎࢆ⥔ᣢࡋࡓሙྜ࡛ࡶ㸪㞴 ⏘ࡼࡿᏊ㤿ࡢṚஸࡸᙅࡼࡾ㸪ṇᖖᏊ㤿ࢆ⏕⏘࡛ࡁ࡞࠸ሙྜࡶ࠶ࡾ㸪ࡇࢀࡽࡀ࣐࢘ࡢ ⦾Ṫ࠾࠸࡚ࡁ࡞ၥ㢟࡞ࡗ࡚࠸ࡿࠋࡇࡢࡓࡵ㸪࣐࢘ࡢዷፎᡂ❧ࡽศፔ⮳ࡿࡲ࡛ࡢ ⏕⌮࠾ࡼࡧែ㛵ࡍࡿ⌮ゎࡀᚲせ࡛࠶ࡿࠋ㍍✀㤿ࡘ࠸࡚ࡢ◊✲ࡣẚ㍑ⓗ㐍ࡵࡽࢀ࡚࠸ ࡿ୍᪉࡛㸪ᾏ㐨༑ᆅ᪉࡛⏕⏘ࡀ┒ࢇ࡞㔜㍛㤿ࡘ࠸࡚ࡢ◊✲ࡣᑡ࡞࠸ࠋࡑࡇ࡛ᮏ◊✲ ࡛ࡣ࣐࢘ࡢዷፎᡂ❧ࡽศፔࡅ࡚㸪㔜㍛㤿ࢆ୰ᚰ㸪ዷፎ୰࠾ࡼࡧ᪂⏕Ꮚࡢ␗ᖖ᳨ฟ ἲ☜❧ࡢࡓࡵࡢᇶ♏࠾ࡼࡧ⮫ᗋ⋇་Ꮫⓗ࡞▱ぢࢆᚓࡿࡇࢆ┠ⓗࡋࡓࠋ ➨1 ❶࡛ࡣ㸪ࢡࢳࣅࣥࡢཷᐜయ㸦ActR㸧-ϨA/B㸪ϩA/B ⺮ⓑࡢⓎ⌧ࢆ㸪ዷፎࡋࡓࢧࣛ ࣈࣞࢵࢻࡢᏊᐑ⫾┙⤌⧊㸪Ꮚᐑෆ⭷ᮼ㸪㯤యࡘ࠸࡚㸪ච⤌⧊Ꮫⓗᡭἲࢆ⏝࠸࡚ㄪᰝ ࡋࡓࠋࡑࡢ⤖ᯝ㸪ActR ࡢ 4 ᆺ࡚ࡀ࣐࢘ࡢᏊᐑෆ⭷ୖ⓶㸪Ꮚᐑ⭢㸪ᰤ㣴⭷㸪Ꮚᐑᖹ➽㸪 Ꮚᐑෆ⭷ᮼ㸪㯤య࠾࠸࡚Ⓨ⌧ࡋ࡚࠸ࡿࡇࡀุ᫂ࡋࡓࠋࢡࢳࣅࣥࡣActR ࡢϨᆺ࠾ࡼ ࡧϩᆺࡀඹᙺࡍࡿࡇ࡛స⏝ࢆⓎࡍࡿࡇࡽ㸪ࡇࢀࡽࡢ⤌⧊࠾ࡅࡿࢡࢳࣅࣥస⏝ Ⓨ⌧ࡀ᥎ᐹࡉࢀࡓࠋࢡࢳࣅࣥࡣࡢື≀࠾࠸࡚Ꮚᐑ⫾┙⤌⧊ࡢ╔ᗋ‽ഛ㸪⬇ࡸ⫾┙㸪 Ꮚᐑ⭢ࡢⓎ㐩㸪Ꮚᐑᖹ➽ࡢ⦰ᛶᢚไ㸪ᰤ㣴⭷⣽⬊ࡢᏊᐑෆ⭷ࡢ㝗ධಁ㐍㸪㯤యᶵ⬟ ᢚไാࡃࡀ㸪࣐࢘࠾࠸࡚ࡶྠᵝࡢస⏝ࡀⓎࡉࢀ࡚࠸ࡿ᥎ᐹࡉࢀࡓࠋ ➨2 ❶࡛ࡣ㸪ዷፎࡋࡓ㔜㍛㤿࠾ࡅࡿ⾑₢୰ࢡࢳࣅࣥ A ⃰ᗘࢆ㸪ዷፎ 7 ࣨ᭶㸦181̽210 ᪥㸧ࡽ12 ࣨ᭶㸦331̽360 ᪥㸧ࡅ࡚㸪ELISA ἲࡼࡾ ᐃࡋࡓࠋᚋ⏘ࢆ᥇ྲྀࡋ㸪3 㢌 ࡀ⌮ᏛⓗAP デ᩿ࡉࢀ㸪ࡑࢀ௨እࡢ⮫ᗋⓗᗣ࡛࠶ࡗࡓ 31 㢌ࢆṇᖖ⩌ࡋࡓࠋṇ ᖖ⩌ࡢ⾑୰ࢡࢳࣅࣥA ⃰ᗘࡣዷፎ 7 ࣨ᭶㸦ᖹᆒ್sᶆ‽೫ᕪ㸪67.24s8.50pg/ml㸧ࡽ 12 ࣨ᭶㸦193.07s1224.80pg/ml㸧ࡅ࡚ቑຍࡋࡓ㸦p < 0.05㸧ࠋAP ࡢ࠺ࡕ 2 㢌ࡀṇᖖ ⩌ࡼࡾ㧗್ࢆ♧ࡋࡓࡀ㸪ࡇࢀࡣ⫾┙࠾ࡅࡿᢠ⅖ᛂ࠾ࡼࡧዷፎ⥔ᣢᶵ⬟ࡢஹ㐍ࡼࡾ㸪 ࢡࢳࣅࣥA ⏘⏕ࡀቑຍࡋࡓ⤖ᯝ࡛࠶ࡿ᥎ᐹࡉࢀࡓࠋAP ࡢṧࡾࡢ 1 㢌ࡣṇᖖ⩌ࡼ ࡾࡶప್ࢆ♧ࡋࡓࡀ㸪ࢡࢳࣅࣥA ࡀ༑ศ⏘⏕࣭ศἪࡉࢀ࡞ࡗࡓ⤖ᯝ࡛࠶ࡿ᥎ᐹࡉ ࢀࡓࠋ௨ୖࡢࡇࡼࡾ㸪ዷፎࡋࡓ㔜㍛㤿ࡢ⾑୰ࢡࢳࣅࣥA ⃰ᗘࡣ㸪⫾┙ࡢᶵ⬟ࡸែ 㛵㐃ࡋ࡚ኚࡋ㸪AP ࠾࠸࡚ṇᖖዷፎ㤿␗࡞ࡿ᥎⛣ࢆ♧ࡍࡇࡀ᫂ࡽ࡞ࡗࡓࠋ ➨3 ❶࡛ࡣ㸪ዷፎࡋࡓ㔜㍛㤿࠾࠸࡚⤒┤⭠㉸㡢Ἴ᳨ᰝࡼࡾ㸪Ꮚᐑ⫾┙⤖ྜཌ
㸦Combined Thickness of the Uterus and Placenta㸸CTUP㸧ࡢ ᐃ⏬ീࡢศᯒࢆᐇࡋࡓࠋ ᚋ⏘ࡢ⌮Ꮫⓗ᳨ᰝࡢ⤖ᯝAP デ᩿ࡉࢀࡓ 3 㢌ࢆ⫾┙⅖⩌ࡋࡓࠋࡑࢀ௨እࡢὶ⏘㸪᪩
⏘㸪እぢୖ᫂ࡽ࡞ወ⫾ዷፎࡢィ7 㢌ࢆ␗ᖖ⏘⩌ࡋࡓࠋ⮫ᗋⓗᗣ࡛㸪AP ࡛࡞࠸ࡇ
5.68̽11.27mm㸧ࡽ 12 ࣨ᭶㸦୰ኸ್ 13.31mm, range 7.44̽16.31mm㸧ࡅ࡚ቑຍࡋ㸦p < 0.05㸧㸪ࡑࡢ್ࡣ㍍✀㤿࠾ࡅࡿ㐣ཤࡢሗ࿌ࡼࡾࡶ㧗್ࢆ♧ࡋࡓࠋࡇࢀࡣ㔜㍛㤿ࡢ⫾┙ࡀ ࡁ࠸ࡓࡵ࡛࠶ࡿ᥎ᐹࡉࢀࡓࠋṇᖖ⩌ࡢୖ25%ࡢಶయࡀྵࡲࢀࡿ➨ 3 ᅄศ㸦ዷፎ 7 ࣨ ᭶7.54mm㸪ዷፎ 12 ࣨ᭶ 15.19mm㸧ࡼࡾࡁ࠸ CTUP ࢆ♧ࡋࡓಶయࡣ⫾┙⅖⩌ 100%㸦3/3 㢌㸧㸪␗ᖖ⩌86%㸦6/7 㢌㸧࡛࠶ࡾ㸪⫾┙⅖࠾ࡼࡧ␗ᖖ⏘࠾࠸࡚ࡣ CTUP ࡀቑຍࡍࡿࡇ ࡀ᥎ᐹࡉࢀࡓࠋ⫾┙㞳ᵝᡤぢࡢⓎ⏕ࡣ㸪ṇᖖ⩌20%㸦5/25 㢌㸧࡛࠶ࡗࡓࡢᑐࡋ㸪⫾┙ ⅖⩌࡛ࡣ67%㸦2/3 㢌㸧㸪␗ᖖ⏘⩌࡛ࡣ 29%㸦2/7 㢌㸧࡛࠶ࡾ㸪⫾┙⅖ࡢ㛵ࡀ᥎ᐹࡉࢀ ࡓࠋᏊᐑ⫾┙⤌⧊ࡢพฝࡣ⩌୍⯡☜ㄆࡉࢀ㸪㔜㍛㤿ࡢ୍⯡ⓗ࡞ᡤぢ࡛࠶ࡿ⪃࠼ࡽ ࢀࡓࠋᏊᐑ⫾┙⤌⧊ࡢ2 ᒙ㸦Ꮚᐑ⫾┙ࡀ㆑ูྍ⬟࡞≧ែ㸧ࡣṇᖖ⩌ 32%㸦8/25 㢌㸧㸪 ⫾┙⅖⩌33%㸦1/3 㢌㸧㸪␗ᖖ⏘⩌ 43%㸦3/7 㢌㸧࠾࠸࡚☜ㄆࡉࢀ㸪ṇᖖ⩌ࡢ 1 㢌ࢆ㝖࠸ ࡚ዷፎ10 ࣨ᭶௨㝆☜ㄆࡉࢀࡓࡇࡽ㸪⫾┙Ⓨ㐩ࢆᫎࡋ࡚࠸ࡿ⪃࠼ࡽࢀࡓࠋ ➨4 ❶࡛ࡣ㞴⏘ࡀ㔜㍛㤿᪂⏕Ꮚࡢ⾑ᾮ㓟ሷᇶᖹ⾮࠾ࡼࡧ⾑Ύங㓟⃰ᗘ࠼ࡿᙳ㡪ࡘ ࠸࡚ㄪᰝࡋࡓࠋ㔜㍛㤿ࡢᏊ35 㢌ࡢ㢕㟼⬦ࡼࡾ㸪ฟ⏕┤ᚋ㸪ฟ⏕ᚋ 1 㛫㸪12 㛫㸪1 ᪥ ᥇⾑ࡋࡓࠋศፔ➨2 ᮇࡀ 30 ศᮍ‶ࡘ 1㹼2 ேࡼࡿ㍍ᗘ≌ᘬࢆᐇࡋࡓ 22 㢌ࢆṇᖖ⏘⩌㸪 ศፔ➨2 ᮇࡀ 30 ศ௨ୖࡘ 3 ே௨ୖ࠶ࡿ࠸ࡣຓ⏘ჾ⏝ࡼࡿᙉᗘ≌ᘬࢆᐇࡋࡓ 13 㢌 ࢆ㞴⏘⩌ࡋࡓࠋฟ⏕┤ᚋ㞴⏘⩌࠾࠸࡚ṇᖖ⏘⩌ࡼࡾࡶ᭷ពప࠸pH㸦p < 0.01㸧㸪㔜 Ⅳ㓟࢜ࣥ⃰ᗘ㸦p < 0.01㸧㸪⥲㓟Ⅳ⣲㸦p < 0.05㸧㸪࣮࣋ࢫ࢚ࢡࢭࢫ㸦p < 0.01㸧࠾ࡼࡧ ᭷ព㧗࠸ࢽ࢜ࣥࢠࣕࢵࣉ㸦p < 0.05㸧㸪⾑Ύ୰ங㓟⃰ᗘࡀ♧ࡉࢀ㸦p < 0.01㸧㸪ங㓟ᛶ௦ ㅰᛶࢩࢻ࣮ࢩࢫࡀ☜ㄆࡉࢀࡓࠋ90mmHg ௨ୖࡢ㓟Ⅳ⣲ศᅽࡣ㸪㞴⏘⩌࡛ࡣ 3 㢌☜ ㄆࡉࢀࡓࡀ㸪ṇᖖ⩌࡛ࡣ☜ㄆࡉࢀࡎ㸪㞴⏘⩌࠾ࡅࡿ㧗Ⅳ㓟࢞ࢫ⾑ࡢࣜࢫࢡࡀ♧၀ࡉࢀ ࡓࠋ㞴⏘୰ࡢ⫾Ꮚᅽ㏕ࡸ⫾┙㞳ࡼࡾ㸪⫾Ꮚ⫾┙⤌⧊ࡀప㑏ὶ࠾ࡼࡧప㓟⣲≧ែ㝗ࡗ ࡚࠸ࡓ᥎ᐹࡉࢀࡓࠋ ௨ୖࡢࡇࡽ㸪ዷፎ⥔ᣢ㔜せ࡞ࢡࢳࣅࣥࡣዷፎ㤿ࡢᏊᐑ⫾┙⤌⧊࠾ࡼࡧ㯤యཷ ᐜయ⺮ⓑࡀⓎ⌧ࡋ㸪స⏝ࢆⓎࡋ࡚࠾ࡾ㸪⾑୰ࢡࢳࣅࣥA ⃰ᗘࡢ ᐃࡣ㔜㍛㤿ࡢୖ⾜ᛶ ⫾┙⅖᳨ฟ᭷⏝࡛࠶ࡿ⪃࠼ࡽࢀࡓࠋࡲࡓ㸪㔜㍛㤿ࡢᏊᐑ⫾┙ཌࡣ㍍✀㤿ࡼࡾࡶࡁࡃ㸪 ࡇࡢ ᐃࡣ㔜㍛㤿ࡢAP ࠾ࡼࡧ␗ᖖ⏘᳨ฟ᭷⏝࡛࠶ࡿ᥎ᐹࡉࢀ㸪㞴⏘ࡣᏊ㤿ங㓟ᛶ ௦ㅰᛶࢩࢻ࣮ࢩࢫࢆⓎ⏕ࡉࡏࡿࡇࡀุ᫂ࡋࡓࠋ
Ꮫ ㄽ ᩥ せ ⣙
Ặ ྡ KIMURA, Yuki
㢟 ┠ Studies on Diagnosis for Abnormal Pregnancy and Evaluation for Neonatal Metabolic Disorders in Heavy Draft Horses
㸦㔜㍛㤿࠾ࡅࡿዷፎ␗ᖖࡢ᪂つデ᩿ἲ☜❧࡞ࡽࡧ᪂⏕Ꮚ௦ㅰ␗ᖖ ࡢホ౯ἲ㛵ࡍࡿ◊✲㸧
In horse reproduction, pregnancy loss occurs in 20% of pregnancy, and the main cause is ascending placentitis (AP). If dams can labor, dystocia and neonatal death and weakness can occur. Therefore, studies about horse pregnancy and parturition from view of physiology and pathology are necessary. In light horse breeds, studies about them are progressed, however studies in heavy draft horses, most of which are bred in Tokachi, Hokkaido, are little. Hence this study aimed to obtain basic and clinical veterinary knowledge for pregnancy and newborn abnormality.
The first study aimed to localize activin receptors (ActRs) I A/B and II A/B using immunohistochemistry in the uteroplacental tissues, endometrial cup (EC), and corpora lutea (CL) in pregnant thoroughbred mares. All four isoforms of ActR expressed in the endometrial epithelium, uterine glands, trophoblasts, myometrium, EC, and CL. Both of ActR - I and II are necessary for expression of activin effects, hence, it was suggested that activin play roles on these tissues. In other animals, activin roles, such as regulation of trophoblast implantation, invasion, and development, development of uterine glands and placenta, myometrial tocolysis, and inhabitation of CL effects, are known, and same effects in horses were speculated.
In second study, plasma activin A was measured in pregnant heavy draft horses by ELISA from 7 to 12 months of pregnancy. Placentas after parturition was pathologically examined, and 3 mares were diagnosed as AP. Thirty-one mares, which were without placentitis and clinically healthy, were in the normal group. Activin A concentration in the normal group was increased as pregnancy progressed from 7 months (median 67.5pg/ml, range 54.4-76.1) to 12 months (median 177.2pg/ml, range 106.3-318.1) of pregnancy (p < 0.05). Activin A concentration in two of AP mares were higher than the normal group, and increased activin A production due to the acceleration of placental anti-inflammatory reaction and pregnancy maintenance mechanism were considered as the reason. Activin A concentration of the one of AP mares was lower than the normal group, and decreased production and secretion was considered as the reason. Based on these results, it was inferred that blood activin A concentration in pregnant heavy draft horses changes with placental function and pathology, and it is different from the normal pattern in AP mares.
In the third study, the combined thickness of the uterus and placenta (CTUP) and ultrasonographic images of uteroplacental tissues were investigated in 35 pregnant heavy draft horses from 7 to 12 months of pregnancy. The mares were divided into three groups: those pathologically diagnosed as placentitis (placentitis group, n=3); those who had abortion, premature birth, or fetal malformation (abnormal group, n=7); and those who had no abnormal findings and clinically healthy (normal group, n=25). In the normal group, CTUP increased as pregnancy
progressed from 7 months (median, 7.08 mm; range, 5.68–11.27) to 12 months of pregnancy (13.31 mm; 7.44–16.31 mm) (p < 0.05) and was higher than those reported previously in light horse breeds; large placentas of heavy draft horses may explain this high CTUP values. Values of CTUP greater than the 75th percentile of the normal group from 7 months (7.54 mm) to 12 months of pregnancy (15.19 mm) were detected in 100% of the placentitis group (3/3) and in 86% of the abnormal group (6/7), and it was suggested that CTUP increased in placentitis and abnormal parturition in heavy draft horses. Ultrasonographic images of placental separation were obtained in 67% of the placentitis group (2/3), 29% of the abnormal group (2/7), and 20% of the normal group (5/25), and relation with placentitis was considered. Ultrasonographic images showing uteroplacental roughness were observed even in the normal group, and this should be common in heavy draft horse. Uteroplacental distinguishability, i.e. clear border line could be seen between these tissues, occurred in 32% of the normal group (1/3), 67% of the placentitis group (6/7), and 43% of the abnormal group (3/7), and this should reflect placental development because this image observed after 10 months of pregnancy exclude one of these mares. These findings suggest that increased CTUP and placental separation would reflect placentitis and abnormal pregnancies and may help to detect them in heavy draft horses.
In the last study, the effects of dystocia on blood acid-base balance and serum lactate concentration in heavy draft newborn foals were investigated. Venous blood samples were collected from 35 foals at 0 hr (within 5 minutes), 1 hr, 12 hr, and 1 day after birth. Normal birth was defined as labor < 30 min without strong fetal traction (n = 22), and dystocia was defined as prolonged labor > 30 min with strong fetal traction (n = 13). The dystocia group, showed lower pH (p < 0.01), bicarbonate (p < 0.01), total carbon dioxide (p < 0.05), and base excess (p < 0.01), and higher anion gap (p < 0.05) and lactate (p < 0.01) at 0 hr. Remarkably high pCO2 values (> 90 mmHg) were observed in three foals in the dystocia group but in none of the foals in the normal birth group at 0 hr. These results suggest that dystocia results in lactic acidosis and may be related to respiratory distress. Fetal compression and placental separation may have resulted in decreased feto-placental perfusion and hypoxia.
Based on these results, following thigs were clarified by this study. First, activin receptors were expressed in the utero placental tissues and CL in horses, and activin, which is important hormone for maintenance of pregnancy, would express actions on these tissues. Second, measuring blood activin concentration in pregnant heavy draft horses can be useful method to detect AP. Third, CTUP values in heavy draft horses were higher than that in light horse breeds, and ultrasonographical examination for measuring CTUP and detecting placental separation would be useful to detect AP and abnormal pregnancy in heavy draft horses. Finally, dystocia caused lactic acidosis in neonatal foals. However, the number of horses used in this study was few, so further investigation with more horses and clinical cases are necessary for the development of reproduction in heavy draft horses.
