Consequences of Growth Hormone Deficiency on Cardiac Structure, Function, and β-Adrenergic Pathway: Studies in Mutant Dwarf Rats1

Autor:	Antonio Cittadini, Hinrik Strömer, Dorothy E. Vatner, Jessica D. Grossman, Sarah E. Katz, Ross Clark, James P. Morgan, Pamela S. Douglas
Rok vydání:	1997
Předmět:	medicine.medical_specialty Adrenergic receptor Dwarfism Propranolol Biology medicine.disease Growth hormone deficiency Contractility Endocrinology Internal medicine medicine Myocyte Triphosphatase Receptor medicine.drug
Zdroj:	Endocrinology. 138:5161-5169
ISSN:	1945-7170 0013-7227
DOI:	10.1210/endo.138.12.5591
Popis:	To evaluate GH’s role in cardiac physiology and its interrelationship with the β-adrenergic system, we studied GH-deficient dwarf (dw/dw) and control rats in 4 groups of 20 each: dwarf group receiving placebo, dwarf-GH group receiving 2 mg/kg GH, dwarf-GH-propranolol group receiving 2 mg/kg GH and 750 mg/liter propranolol, and a control group of Lewis rats receiving placebo. Dwarf rats showed reduced left ventricular weight and myocyte cross-sectional area, and impaired cardiac performance in vitro. Left ventricular pressure-volume curves showed a shift upward and leftward, indicating reduced distensibility. These abnormalities reversed after GH treatment regardless of concomitant propranolol administration. Although isoproterenolol responsiveness was reduced in dwarf rats, there were no differences in β-adrenergic receptor density, affinity, Na+,K+-adenosine triphosphatase activity, or adenylyl cyclase activity. In summary, myocyte size, cardiac structure, myocardial contractility, and distensibility are...
Databáze:	OpenAIRE
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