Sympathetic control of intracellular pH in guinea pig ventricular myocytes

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Title Sympathetic control of intracellular pH in guinea pig ventricular myocytes
Publication Type dissertation
School or College School of Medicine
Department Physiology
Author Skolnick, Rita Lynette
Date 1994-12
Description Catecholamines affect intracellular pH (pHi) by changing the activities of the ion transporters involved in pHi regulation, but the results are confusing and the mechanisms are not clear. This study examined the effects of catecholamines on pHi regulatory systems. In addition, the intracellular mechanisms involved in the catecholamine responses were investigated. Intracellular pHi was measured in adult guinea pig ventricular myocytes with the fluorescent proton indicator, SNARF-1. In the absence of C02/HC0¯3, the ?1-adrenergic agonist, phenylephrine, caused an increase in steady state pHi and enhanced the rate of pHi recovery from acid loading (dpHi/dt). The phorbol ester, PMA and the DAG analog, DiC8 1,2 had a similar effect. PMA effects on pHi were abolished by staurosporine, a protein kinase C (PKC) inhibitor, and the amiloride derivative, EIPA. PMA effects on steady state pHi were not affected by changes in intracellular Ca2+. These results suggest that the ?1-agonist stimulates Na+/H+ exchange and that the effect is mediated by a Ca2+ independent form of PKC. In the absence of C02/HC0¯3, the ?1-agonist, isoproterenol (ISO), caused a fall in steady state pHi that was sensitive to EIPA and Na+o but not Ca2+. The ISO-induced acidosis was slightly decreased by the cAMP-dependent protein kinase inhibitor, HA-1004. ISO caused an attenuation of dpHi/dt; however agents that increase cAMP (forskolin and milrinone) have an opposite effect. ?1-adrenergic stimulation appears to modulate Na+/H+ exchange. ISO-induced inhibition of Na+/H+ exchange is not caused by an increase in Ca2+i. In addition, techniques that increase cAMP or inhibit cAMP-dependent protein kinase activity do not mimic the ISO effect; therefore Na+/H+ exchange inhibition is not mediated through a cAMP-dependent pathway.
Type Text
Publisher University of Utah
Subject Cell physiology; Catecholamines
Subject MESH Cell Physiology; Catecholamines
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "Sympathetic control of intracellular pH in guinea pig ventricular myocytes Spencer S. Eccles Health Sciences Library.
Rights Management © Rita Lynette Skolnick.
Format application/pdf
Format Medium application/pdf
Format Extent 1,347,766 bytes
Identifier undthes,4253
Source Original: University of Utah Spencer S. Eccles Health Sciences Library (no longer available)
Master File Extent 1,347,798 bytes
ARK ark:/87278/s6mp551d
Setname ir_etd
ID 190663
Reference URL https://collections.lib.utah.edu/ark:/87278/s6mp551d
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