Calciotrophic hormones during experimental hypocalcaemia and hypercalcaemia in spontaneously diabetic rats
| Autor: | Johan Verhaeghe, Roger Bouillon, Z Zaman, R. Van Bree, Ivo Jans, E Van Herck |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Male
Glycosuria medicine.medical_specialty Calcitriol Endocrinology Diabetes and Metabolism medicine.medical_treatment Parathyroid hormone chemistry.chemical_compound Endocrinology Internal medicine Diabetes mellitus Vitamin D and neurology Animals Medicine Hypocalcaemia Rats Wistar Egtazic Acid Saline Hypocalcemia business.industry medicine.disease Rats EGTA Diabetes Mellitus Type 1 chemistry Parathyroid Hormone Hypercalcemia medicine.symptom business medicine.drug |
| Zdroj: | Journal of Endocrinology. 162:251-258 |
| ISSN: | 1479-6805 0022-0795 |
| DOI: | 10.1677/joe.0.1620251 |
| Popis: | 1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) concentrations have been found to be decreased in diabetic humans and rats. To investigate further the regulation of plasma Ca in diabetes, first we measured Ca(2+), P, Mg, parathyroid hormone(1-34) (PTH), and total and free 1,25(OH)(2)D(3) in male spontaneously diabetic rats 7 and 28 days after the onset of glycosuria. Secondly, we studied changes in the levels of PTH and 1,25(OH)(2)D(3) in response to hypocalcaemia induced by an i.v. infusion of EGTA (2.5%, wt/vol.) for 24 h, and changes in the levels of 1,25(OH)(2)D(3) in response to an i.v. infusion of rat PTH (10 microgram over 24 h) without or with concomitant EGTA infusion (producing hypercalcaemia or normo/hypocalcaemia respectively), in diabetic and control rats. Ca(2+), P, Mg and PTH concentrations remained within the control ranges after 7 and 28 days of glycosuria; 1,25(OH)(2)D(3) concentrations were decreased after 7, but not after 28, days of glycosuria. PTH concentrations showed a similar rise during EGTA-induced hypocalcaemia in control and diabetic rats compared with saline-infused rats, whereas 1,25(OH)(2)D(3) concentrations were unchanged in both groups. Total and free 1,25(OH)(2)D(3) levels were comparably (about 3-fold) increased during PTH, but not during combined PTH and EGTA infusion in control and diabetic rats. Total 1, 25(OH)(2)D(3) concentrations were lower in the diabetic groups infused with saline or PTH than in their respective controls, and there was a similar trend in the PTH+EGTA-infused group; free 1, 25(OH)(2)D(3) levels, however, were normal or increased in the diabetic groups, confirming our previous data. The novel finding of this study is that, despite severe insulin deficiency and altered 1, 25(OH)(2)D(3) levels, the in vivo response of PTH levels to hypocalcaemia and the in vivo response of 1,25(OH)(2)D(3) levels to PTH in diabetic rats are comparable with those found in nondiabetic rats. |
| Databáze: | OpenAIRE |
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