Calcium Channel Alterations in Genetic Hypertension

• Published in: Hypertension (Dallas, Tex. 1979) Vol. 14; no. 4; pp. 453 - 456
• Main Authors: Hermsmeyer, Kent, Rusch, Nancy J
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Heart Association, Inc 01.10.1989; Hagerstown, MD Lippincott
• Subjects: Animals; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Calcium - physiology; Calcium Channels - physiology; Cardiology. Vascular system; Cells, Cultured; Egtazic Acid - pharmacology; Experimental diseases; Hypertension - genetics; Hypertension - physiopathology; In Vitro Techniques; Medical sciences; Muscle, Smooth, Vascular - physiopathology; Rats; Rats, Inbred SHR - physiology; Rats, Inbred Strains - physiology; Rats, Inbred WKY; Hypertension; Cell culture; Calcium; Rat; Rodentia; Ion transport; Cardiovascular disease; Smooth muscle; Ionic channel; Hereditary; Vertebrata; Mammalia; Membrane transport; Animal; Blood vessel; Cell
• DOI: 10.1161/01.hyp.14.4.453
• ISSN: 0194-911X

We proposed earlier that voltage-dependent calcium (Ca) current is altered in single azygos venous cells from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). In this study, the effects of different intracellular concentrations of ethylene glycol-bis- N,N,Nʼ,NʼVtetraacetic acid (EGTA) on Ca currents were investigated. Vascular muscle cells from SHR and WKY rats were equilibrated with pipette solution containing 0.1 mM or 10 mM EGTA. Increasing the EGTA concentration from 0.1 to 10 mM in SHR vascular cells significantly enhanced the peak amplitude of the longer lasting (L) current from 87 ±12 pA to 152 ±8 pA, while the transient (T) current amplitude was not significantly different (52 ±7 pA and 36±7 pA, respectively). In WKY rat vascular muscle cells, the amplitudes of the T and L currents were not significantly different with the same comparison of intracellular EGTA concentrations. These observations suggest that relatively low intracellular Ca concentrations can more strongly modulate Ca current through the L channel in SHR than WKY rat vascular muscle cells.