PMID- 28661009
OWN - NLM
STAT- MEDLINE
DCOM- 20180406
LR  - 20181113
IS  - 1939-1676 (Electronic)
IS  - 0891-6640 (Print)
IS  - 0891-6640 (Linking)
VI  - 31
IP  - 5
DP  - 2017 Sep
TI  - The Effect of Geographic Location on Circannual Adrenocorticotropic Hormone 
      Plasma Concentrations in Horses in Australia.
PG  - 1533-1540
LID - 10.1111/jvim.14782 [doi]
AB  - BACKGROUND: Longitudinal evaluation of plasma endogenous ACTH concentration in 
      clinically normal horses has not been investigated in the Southern Hemisphere. 
      OBJECTIVES: To longitudinally determine monthly upper reference limits for plasma 
      ACTH in 2 disparate Australian geographic locations and to examine whether 
      location affected the circannual rhythm of endogenous ACTH in the 2 groups of 
      horses over a 12-month period. ANIMALS: Clinically normal horses <20 years of age 
      from 4 properties (institutional herd and client owned animals) in Perth (n = 40) 
      and Townsville (n = 41) were included in the study. METHODS: A prospective 
      longitudinal descriptive study to determine the upper reference limit and 
      confidence intervals for plasma ACTH in each geographic location using the ASVCP 
      reference interval (RI) guidelines, for individual months and monthly groupings 
      for 12 consecutive months. RESULTS: Plasma endogenous ACTH concentrations 
      demonstrated a circannual rhythm. The increase in endogenous ACTH was not 
      confined to the autumnal months but was associated with changes in photoperiod. 
      During the quiescent period, plasma ACTH concentrations were lower, </=43 pg/mL 
      (upper limit of the 90% confidence interval (CI)) in horses from Perth and </=67 
      pg/mL (upper limit of the 90% CI) in horses from Townsville, than at the 
      acrophase, </=94 pg/mL (upper limit of the 90% CI) in horses from Perth, </=101 pg/mL 
      (upper limit of the 90% CI) in horses from Townsville. CONCLUSIONS AND CLINICAL 
      IMPORTANCE: Circannual rhythms of endogenous ACTH concentrations vary between 
      geographic locations, this could be due to changes in photoperiod or other 
      unknown factors, and upper reference limits should be determined for specific 
      locations.
CI  - Copyright (c) 2017 The Authors. Journal of Veterinary Internal Medicine published 
      by Wiley Periodicals, Inc. on behalf of the American College of Veterinary 
      Internal Medicine.
FAU - Secombe, C J
AU  - Secombe CJ
AUID- ORCID: 0000-0003-2268-1452
AD  - College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch 
      University, Murdoch, WA, Australia.
FAU - Tan, R H H
AU  - Tan RHH
AD  - Discipline of Veterinary Clinical Sciences, College of Public Health, Medical and 
      Veterinary Sciences, James Cook University, Townsville, QLD, Australia.
FAU - Perara, D I
AU  - Perara DI
AD  - College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch 
      University, Murdoch, WA, Australia.
FAU - Byrne, D P
AU  - Byrne DP
AD  - College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch 
      University, Murdoch, WA, Australia.
FAU - Watts, S P
AU  - Watts SP
AD  - Discipline of Veterinary Clinical Sciences, College of Public Health, Medical and 
      Veterinary Sciences, James Cook University, Townsville, QLD, Australia.
FAU - Wearn, J G
AU  - Wearn JG
AD  - Discipline of Veterinary Clinical Sciences, College of Public Health, Medical and 
      Veterinary Sciences, James Cook University, Townsville, QLD, Australia.
LA  - eng
PT  - Journal Article
DEP - 20170629
PL  - United States
TA  - J Vet Intern Med
JT  - Journal of veterinary internal medicine
JID - 8708660
RN  - 9002-60-2 (Adrenocorticotropic Hormone)
SB  - IM
MH  - Adrenocorticotropic Hormone/*blood
MH  - Animals
MH  - Australia
MH  - Female
MH  - Horses/*blood/physiology
MH  - Longitudinal Studies
MH  - Male
MH  - Prospective Studies
MH  - Seasons
PMC - PMC5598888
OTO - NOTNLM
OT  - ACTH
OT  - Horse
OT  - Photoperiod
OT  - Reference limit
EDAT- 2017/07/01 06:00
MHDA- 2018/04/07 06:00
PMCR- 2017/09/01
CRDT- 2017/06/30 06:00
PHST- 2016/11/21 00:00 [received]
PHST- 2017/04/11 00:00 [revised]
PHST- 2017/05/17 00:00 [accepted]
PHST- 2017/07/01 06:00 [pubmed]
PHST- 2018/04/07 06:00 [medline]
PHST- 2017/06/30 06:00 [entrez]
PHST- 2017/09/01 00:00 [pmc-release]
AID - JVIM14782 [pii]
AID - 10.1111/jvim.14782 [doi]
PST - ppublish
SO  - J Vet Intern Med. 2017 Sep;31(5):1533-1540. doi: 10.1111/jvim.14782. Epub 2017 
      Jun 29.