| Autor: |
Connolly, Cynthia C., Aglione, Lisa N., Smith, Marta S., Lacy, D. Brooks, Moore, Mary Courtney |
| Předmět: |
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| Zdroj: |
American Journal of Physiology: Endocrinology & Metabolism; Sep2004, Vol. 287, pE480-E488, 9p, 2 Charts, 20 Graphs |
| Abstrakt: |
The impact of pregnancy on the counterregulatory response to insulin-induced hypoglycemia was examined in six nonpregnant (NP) and six pregnant (P; 3rd trimester) conscious dogs by tracer and arteriovenous difference techniques. After basal sampling, insulin was infused intraportally at 30 pmol·kg-1·min-1 for 180 min. Insulin rose from 70 ± 15 to 1,586 ± 221 pmol/1 and 27 ± 4 to 1,247 ± 61 pmol/1 in the 3rd h in NP and P, respectively. Arterial glucose fell from 5.9 ± 0.2 to 2.3 ± 0.2 mmol/l in P. Glucose was infused in NP to equate the rate of fall of glucose and the steady-state concentrations in the groups (5.9 ± 0.2 to 2.3 ± 0.1 mmol/l in NP). Glucagon was 32 ± 6, 69 ± 11, and 48 ± 10 ng/l (basal and 1st and 3rd h) in NP, but the response was attenuated in P (34 ± 5, 46 ± 6, 41 ± 9 ng/l). Cortisol and epinephrine rose similarly in both groups, but norepinephrine rose more in NP (Δ3.01 ± 0.46 and Δ1.31 ± 0.13 nmol/l, P < 0.05). Net hepatic glucose output (NHGO; µmol·kg-1·min-1) increased from 10.6 ± 1.8 to 21.2 ± 3.3 in NP (3rd h) but did not increase in P (15.1 ± 1.5 to 15.3 ± 2.8 µmol·kg-1·min-1, P < 0.05 between groups). The glycogenolytic contribution to NHGO in NP increased from 5.8 ± 0.7 to 10.4 ± 2.5 µmol·kg-1·min-1 by 90 min but steadily declined in P. The increase in glycerol levels and the gluconeogenic contribution to NHGO were 50% less in P than in NP, but ketogenesis did not differ. The glucagon and norepinephrine responses to insulin-induced hypoglycemia are blunted in late pregnancy in the dog, impacting on the magnitude of the metabolic responses to the fall in glucose. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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