Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.

Ten beluga whales, Delphinapterus leucas, were captured in the Churchill River, Manitoba, held for up to five days, and then released. Blood samples were obtained immediately after capture and at 6-7 h intervals thereafter to monitor changes in circulating levels of thyroid hormones (TH). In six of...

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Main Authors: St Aubin, D J, Geraci, J R
Format: Text
Language:English
Published: 1992
Subjects:
Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1263494
http://www.ncbi.nlm.nih.gov/pubmed/1586888
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record_format openpolar
spelling ftpubmed:oai:pubmedcentral.nih.gov:1263494 2023-05-15T15:41:46+02:00 Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin. St Aubin, D J Geraci, J R 1992-01 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1263494 http://www.ncbi.nlm.nih.gov/pubmed/1586888 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1263494 http://www.ncbi.nlm.nih.gov/pubmed/1586888 Research Article Text 1992 ftpubmed 2013-08-30T16:11:25Z Ten beluga whales, Delphinapterus leucas, were captured in the Churchill River, Manitoba, held for up to five days, and then released. Blood samples were obtained immediately after capture and at 6-7 h intervals thereafter to monitor changes in circulating levels of thyroid hormones (TH). In six of the whales, total and free thyroxine (T4) and triiodothyronine (T3) declined steadily, whereas reverse-T3 (rT3) showed a transient increase during the first 24-36 h, followed by a decrease to below initial values. The changes in TH may have been due to glucocorticoid-mediated reduction in endogenous thyroid stimulating hormone (TSH), and inhibition of 5'-monodeiodinase in peripheral tissue. Two whales were given 10 IU of bovine TSH immediately after capture, and again one and two days later, resulting in successive increases in all TH, which remained elevated for at least 24 h after the last injection. Thereafter, circulating levels declined as in the untreated whales. Two whales receiving a single TSH injection on the fourth day responded with an increase in plasma TH comparable to that observed following the first TSH injection in the other two animals. Average (+/- SD) circulating level of rT3 at capture was 6.3 +/- 3.1 nmol/L, which is higher than reported for any other mammal and was significantly correlated with the naturally elevated levels of T4 that occur in belugas occupying estuaries during the summer. Text Beluga Beluga* Churchill Churchill River Delphinapterus leucas PubMed Central (PMC)
institution Open Polar
collection PubMed Central (PMC)
op_collection_id ftpubmed
language English
topic Research Article
spellingShingle Research Article
St Aubin, D J
Geraci, J R
Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.
topic_facet Research Article
description Ten beluga whales, Delphinapterus leucas, were captured in the Churchill River, Manitoba, held for up to five days, and then released. Blood samples were obtained immediately after capture and at 6-7 h intervals thereafter to monitor changes in circulating levels of thyroid hormones (TH). In six of the whales, total and free thyroxine (T4) and triiodothyronine (T3) declined steadily, whereas reverse-T3 (rT3) showed a transient increase during the first 24-36 h, followed by a decrease to below initial values. The changes in TH may have been due to glucocorticoid-mediated reduction in endogenous thyroid stimulating hormone (TSH), and inhibition of 5'-monodeiodinase in peripheral tissue. Two whales were given 10 IU of bovine TSH immediately after capture, and again one and two days later, resulting in successive increases in all TH, which remained elevated for at least 24 h after the last injection. Thereafter, circulating levels declined as in the untreated whales. Two whales receiving a single TSH injection on the fourth day responded with an increase in plasma TH comparable to that observed following the first TSH injection in the other two animals. Average (+/- SD) circulating level of rT3 at capture was 6.3 +/- 3.1 nmol/L, which is higher than reported for any other mammal and was significantly correlated with the naturally elevated levels of T4 that occur in belugas occupying estuaries during the summer.
format Text
author St Aubin, D J
Geraci, J R
author_facet St Aubin, D J
Geraci, J R
author_sort St Aubin, D J
title Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.
title_short Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.
title_full Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.
title_fullStr Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.
title_full_unstemmed Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.
title_sort thyroid hormone balance in beluga whales, delphinapterus leucas: dynamics after capture and influence of thyrotropin.
publishDate 1992
url http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1263494
http://www.ncbi.nlm.nih.gov/pubmed/1586888
genre Beluga
Beluga*
Churchill
Churchill River
Delphinapterus leucas
genre_facet Beluga
Beluga*
Churchill
Churchill River
Delphinapterus leucas
op_relation http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1263494
http://www.ncbi.nlm.nih.gov/pubmed/1586888
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