ATP-sensitive potassium channels regulate stimulated ANF secretion in isolated rat heart
| Autor: | Alex J. Baertschi, T. Xu, Jin-Hua Jiao, Richard A. Pence |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
medicine.medical_specialty Potassium Channels Physiology Tolbutamide In Vitro Techniques chemistry.chemical_compound Adenosine Triphosphate Atrial natriuretic peptide Physical Stimulation Physiology (medical) Internal medicine Pressure otorhinolaryngologic diseases medicine Diazoxide Animals Rats Wistar Hypoxia Dose-Response Relationship Drug Myocardium Potassium channel blocker Hypoxia (medical) musculoskeletal system Potassium channel Rats Dose–response relationship Endocrinology chemistry Pinacidil cardiovascular system Atrial Function Left medicine.symptom Cardiology and Cardiovascular Medicine Atrial Natriuretic Factor hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 271:H2339-H2345 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.1996.271.6.h2339 |
| Popis: | Perfused hearts (n = 127) were exposed to acute hypoxia (10% O2 for 12 or 20 min) or left atrial stretch (increase in atrial pressure) in the presence or absence of 100 mumol/l ATP-sensitive potassium channel blocker (tolbutamide) or openers (pinacidil and diazoxide). Hypoxia alone elicited a prolonged atrial natriuretic factor (ANF) release, peaking at 74% over baseline (P < 0.01); with tolbutamide, ANF secretion peaked at 132% over baseline (P < 0.01). Pinacidil and diazoxide abolished the ANF response to hypoxia (P < 0.01). Atrial stretch alone (1 mmHg) transiently (2 min) increased ANF by 56% (P < 0.05); with tolbutamide, ANF increased transiently by 124% and showed a prolonged increase of 52% (P < 0.05). With tolbutamide, graded stretch (0.5-2.3 mmHg) induced a bell-shaped transient (2-min) increase of ANF release [-3% at 0.5 mmHg, 124% (P < 0.05) at 1.0 mmHg, 80% (P < 0.05) at 1.48 mmHg, and 14% at 2.22 mmHg] and a saturating prolonged ANF response. Tolbutamide increased the ANF response nonsignificantly at lower doses (30 mumol/l) and had no effect at 1 mumol/l. Pinacidil abolished the stretch-induced ANF release. These results suggest that ATP-sensitive potassium channels are extremely potent modulators of stimulated ANF secretion. |
| Databáze: | OpenAIRE |
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