Biomaterial Database

Potassium currents in ventricular myocytes from genetically diabetic rats. 1997

K Tsuchida, and H Watajima

Research Center, Taisho Pharmaceutical Company, Ohmiya, Saitama, Japan.

Our previous study demonstrated the longer duration of action potential in ventricular myocytes from genetically diabetic WBN/Kob rats without change in calcium channel density compared with age-matched controls [Tsuchida, K., H. Watajima, and S. Otamo. Am. J. Physiol. 267 (Heart Circ. Physiol. 36): H2280-H2289, 1994]. In the present study we examined the alteration of potassium currents, especially transient outward current, in ventricular myocytes of genetically diabetic WBN/Kob rats. WBN/Kob rats gradually develop hyperglycemia with aging and show some similarity to non-insulin-dependent diabetes mellitus models, which differ from the insulin-dependent streptozotocin-treated rat model. The density of the intracellular calcium ion-independent transient outward current (I(to)) from 17- to 19-mo diabetic rat myocytes was significantly smaller than that from age-matched control rat myocytes. In addition, the density of I(to) from 17- to 19-mo rat myocytes was significantly less than that from 2-mo rat myocytes, suggesting that aging-induced alteration of I(to) was accelerated by the diabetic state. The steady-state inactivation curves of I(to), the recovery from I(to) inactivation, and the other outward currents were not significantly altered between diabetic myocytes and age-matched control myocytes. In conclusion, the prolonged duration of action potential from genetically diabetic rat myocytes is mainly due to the depressed I(to).

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D011922	Rats, Mutant Strains	Rats bearing mutant genes which are phenotypically expressed in the animals.	Mutant Strains Rat,Mutant Strains Rats,Rat, Mutant Strains,Strains Rat, Mutant,Strains Rats, Mutant
D001786	Blood Glucose	Glucose in blood.	Blood Sugar,Glucose, Blood,Sugar, Blood
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D003922	Diabetes Mellitus, Type 1	A subtype of DIABETES MELLITUS that is characterized by INSULIN deficiency. It is manifested by the sudden onset of severe HYPERGLYCEMIA, rapid progression to DIABETIC KETOACIDOSIS, and DEATH unless treated with insulin. The disease may occur at any age, but is most common in childhood or adolescence.	Diabetes Mellitus, Brittle,Diabetes Mellitus, Insulin-Dependent,Diabetes Mellitus, Juvenile-Onset,Diabetes Mellitus, Ketosis-Prone,Diabetes Mellitus, Sudden-Onset,Diabetes, Autoimmune,IDDM,Autoimmune Diabetes,Diabetes Mellitus, Insulin-Dependent, 1,Diabetes Mellitus, Type I,Insulin-Dependent Diabetes Mellitus 1,Juvenile-Onset Diabetes,Type 1 Diabetes,Type 1 Diabetes Mellitus,Brittle Diabetes Mellitus,Diabetes Mellitus, Insulin Dependent,Diabetes Mellitus, Juvenile Onset,Diabetes Mellitus, Ketosis Prone,Diabetes Mellitus, Sudden Onset,Diabetes, Juvenile-Onset,Diabetes, Type 1,Insulin Dependent Diabetes Mellitus 1,Insulin-Dependent Diabetes Mellitus,Juvenile Onset Diabetes,Juvenile-Onset Diabetes Mellitus,Ketosis-Prone Diabetes Mellitus,Sudden-Onset Diabetes Mellitus
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D006352	Heart Ventricles	The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.	Cardiac Ventricle,Cardiac Ventricles,Heart Ventricle,Left Ventricle,Right Ventricle,Left Ventricles,Right Ventricles,Ventricle, Cardiac,Ventricle, Heart,Ventricle, Left,Ventricle, Right,Ventricles, Cardiac,Ventricles, Heart,Ventricles, Left,Ventricles, Right
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia