Intracellular Ca2+ contributes to K+-induced increase in renal kallikrein secretion
| Autor: | Masataka Majima, Michiko Ogino, Tomoe Fujita, Futaba Daigo, Tomoko Yamaguchi |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Intracellular Fluid
Male medicine.medical_specialty Kidney Cortex Thapsigargin medicine.medical_treatment Immunology Tissue kallikrein Diuresis urologic and male genital diseases Polyethylene Glycols Rats Sprague-Dawley Thiazides Excretion chemistry.chemical_compound Internal medicine medicine Animals Immunology and Allergy Secretion Pharmacology Kidney Chemistry Rats medicine.anatomical_structure Endocrinology Potassium Calcium Kallikreins Trichlormethiazide Diuretic medicine.drug |
| Zdroj: | International Immunopharmacology. 6:1487-1495 |
| ISSN: | 1567-5769 |
| Popis: | We have reported that natriuretic effects of K(+) are involved in enhancement of renal kallikrein-kinin system. The study was aimed to examine 1) comparison of augmentative effects of K(+) on urinary KK excretion with non-specific washout effects by trichlormethiazide (thiazide), polyethyleneglycol 200 (PEG) and rapid physiological saline infusion, 2) contribution of Ca(2+) on the K(+)-induced increase in renal kallikrein secretion. Renal kallikrein activities were measured as fluorescence activities of methylcoumarinylamide-labeled synthetic substrate of tissue kallikrein (TK). Increases in urinary TK excretion were simultaneously observed with diuresis caused by thiazide, PEG, and rapid saline infusion. K(+) infusion increased urinary TK excretion with a diuretic response same as the control. K(+), but not thiazide, showed an early increase in renal TK secretion dose dependently in the kidney slices. Increases in renal TK secretion persisted during treatment with K(+). Neither voltage-dependent Ca(2+)-channel blockers such as verapamil and nifedipine nor simultaneous treatment of EDTA affected on the K(+)-induced increase in renal TK secretion. While, EDTA decreased the K(+)-induced increases in renal TK secretion with time. Caffeine also had an early effect on the increase in renal TK secretion. K(+)-induced increases in renal TK secretion was demonstrated even after treatment with ryanodine or depletion of caffeine-sensitive intracellular Ca(2+) by thapsigargin. It was indicated that the increase in renal TK secretion by K(+) depends on the intracellular Ca(2+) and the caffeine-sensitive release of intracellular Ca(2+) may not be involved in this response. Mechanisms for the K(+)-induced increase in renal TK secretion needs to be further elucidated. |
| Databáze: | OpenAIRE |
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