{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T14:18:44Z","timestamp":1783520324771,"version":"3.55.0"},"reference-count":0,"publisher":"Bioscientifica","issue":"1","content-domain":{"domain":["journals.bioscientifica.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1997,10,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Parathyroid function was studied in 14 normal dogs 1 month before and after daily i.v. administration of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) (eight dogs), or about 50% parathyroidectomy (six dogs), to test the hypothesis that degradation of newly synthesized intact parathyroid hormone (I-PTH) is involved in parathyroid gland adjustment to a modified demand for I-PTH. Parathyroid function was studied through i.v. infusions of Na2EDTA and CaCl2 and measurement of ionized calcium (Ca2+), I-PTH and carboxyl-terminal PTH (C-PTH) at various time points. The C-PTH\/I-PTH ratio was used as an index for change in the relative proportion of circulating C-PTH vs I-PTH, 1 month prior to and following each intervention. This ratio was further validated by looking at the HPLC profile of I- and C-PTH in hypo- and hypercalcemia under experimental conditions. Basal Ca2+ was unaltered 1 month after surgery, and was maintained constant in the 1,25-(OH)2D3-treated group by gradually decreasing 1,25-(OH)2D3 doses over time from 0.25 to 0.13 microgram twice daily during the last week of the experimental protocol. In this same group, basal 1,25-(OH)2D3 was increased by 65% (P &amp;lt; 0.0001) and basal I-PTH was decreased by 40% (P &amp;lt; 0.05), while basal C-PTH and the C-PTH\/I-PTH ratio remained unchanged. Stimulated and non-suppressible I- and C-PTH followed the same pattern with, this time, an increase of stimulated and non-suppressible C-PTH\/I-PTH ratio of 60% (P &amp;lt; 0.05) and 85% (P &amp;lt; 0.05) respectively. There was no change in basal I-PTH, C-PTH, or C-PTH\/I-PTH ratio after surgery. However, stimulated I- and C-PTH were decreased by 45% (P &amp;lt; 0.005) and 65% (P &amp;lt; 0.005) respectively, with a 30% (P &amp;lt; 0.005) decrease of stimulated C-PTH\/I-PTH ratio. There was no change in non-suppressible I-PTH, while non-suppressible C-PTH decreased by 55% (P &amp;lt; 0.005), with a 55% (P &amp;lt; 0.05) decrease in non-suppressible C-PTH\/I-PTH ratio. The HPLC profiles of I- and C-PTH obtained in hypo- and hypercalcemia disclosed a similar distribution of the immuno-reactivity into peaks before and after i.v. administration of 1,25-(OH)2D3 as well as partial parathyroidectomy. This indicated that C-PTH\/I-PTH ratio changes were related to different circulating levels of I- and C-PTH rather than to a different composition of I- and C-PTH. These data indicate a shift in the circulating PTH profile toward more PTH carboxyl-terminal fragments after 1 month of i.v. 1,25-(OH)2D3, but toward more intact PTH 1 month after about 50% parathyroidectomy, possibly reflecting adjustments in PTH degradation induced by a modified demand for I-PTH. Although these changes are most likely modulated at the parathyroid gland level, we cannot formally eliminate participation of the hormone's peripheral metabolism.<\/jats:p>","DOI":"10.1677\/joe.0.1550133","type":"journal-article","created":{"date-parts":[[2004,12,2]],"date-time":"2004-12-02T18:42:13Z","timestamp":1102012933000},"page":"133-141","update-policy":"https:\/\/doi.org\/10.1530\/crossmarkpolicy-5","source":"Crossref","is-referenced-by-count":17,"title":["Adaptation of parathyroid function to intravenous 1,25-dihydroxyvitamin D3 or partial parathyroidectomy in normal dogs"],"prefix":"10.1530","volume":"155","author":[{"given":"M","family":"Cloutier","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Y","family":"Gagnon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M","family":"Gascon-Barre","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"JH","family":"Brossard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P","family":"D'Amour","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"416","container-title":["Journal of Endocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/joe.bioscientifica.com\/view\/journals\/joe\/155\/1\/133.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.bioscientifica.com\/joe\/article-pdf\/155\/1\/133\/106441\/133.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/journals.bioscientifica.com\/joe\/article-pdf\/155\/1\/133\/106441\/133.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T13:32:02Z","timestamp":1783517522000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.bioscientifica.com\/joe\/article\/155\/1\/133\/19126\/Adaptation-of-parathyroid-function-to-intravenous"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1997,10,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1997,10,1]]}},"URL":"https:\/\/doi.org\/10.1677\/joe.0.1550133","relation":{},"ISSN":["1479-6805","0022-0795"],"issn-type":[{"value":"1479-6805","type":"electronic"},{"value":"0022-0795","type":"print"}],"subject":[],"published":{"date-parts":[[1997,10,1]]}}}