Angiotensin II triggers EGFR tyrosine kinase-dependent Ca2+ influx in afferent arterioles

Research output: Contribution to journalArticle

31 Scopus citations

Abstract

We previously reported that inhibition of epidermal growth factor receptor tyrosine kinase activity attenuates renal arteriolar contractile responses to angiotensin II. We performed the present experiments to determine if epidermal growth factor receptor tyrosine kinase activity contributes to the afferent arteriolar intracellular [Ca2+] response to angiotensin II. Afferent arterioles were dissected from rat kidney and intracellular [Ca2+] was monitored with the use of fura-2. In normal Ringer's bath containing 1.5 mmol/L Ca2+, basal intracellular [Ca2+] averaged 95±7 nmol/L and 100 nmol/L angiotensin II caused a rapid rise (peak Δ=75±10 nmol/L) that waned to a plateau averaging 24±5 nmol/L above baseline. Pretreatment with 100 nmol/L AG1478 (epidermal growth factor receptor tyrosine kinase inhibitor) reduced both the peak and the plateau stages of the angiotensin II response (peak Δ=42±7 nmol/L; plateau Δ=8±4 nmol/L). A structurally unrelated epidermal growth factor receptor tyrosine kinase inhibitor also suppressed the peak response to angiotensin II, whereas tyrosine phosphatase inhibition enhanced the plateau phase of the response. In the presence of 100 nmol/L extracellular Ca2+, the angiotensin II response was characterized by a peak of diminished magnitude (Δ=49±10 nmol/L; P<0.05 versus the response in normal Ringer's bath) with no plateau, and this response was unaffected by AG1478. Moreover, angiotensin II stimulation of divalent cation influx (Mn2+ quench of fura-2 fluorescence) was decreased significantly by AG1478. We conclude that epidermal growth factor receptor tyrosine kinase activity contributes to the afferent arteriolar intracellular [Ca2+] response to angiotensin II and that this process involves promotion of Ca2+ influx.

Original languageEnglish (US)
Pages (from-to)700-706
Number of pages7
JournalHypertension
Volume40
Issue number5
DOIs
StatePublished - Nov 1 2002

Keywords

  • Angiotensin
  • Calcium
  • Epidermal growth factor
  • Muscle, smooth vascular
  • Protein kinases
  • Renal circulation

ASJC Scopus subject areas

  • Internal Medicine

Fingerprint Dive into the research topics of 'Angiotensin II triggers EGFR tyrosine kinase-dependent Ca<sup>2+</sup> influx in afferent arterioles'. Together they form a unique fingerprint.

  • Cite this