Document Detail

Selective effects of alpha-methyldopa on myocardial cell components independent of cell size in normotensive and genetically hypertensive rats.
MedLine Citation:
PMID:  6759393     Owner:  NLM     Status:  MEDLINE    
Alpha methyldopa has been shown to modify left ventricular mass and normalize mitochondria/myofibrils volume ratio in spontaneously hypertensive rats (SHR) when administered during the stage of developing cardiac hypertrophy (Tomanek et al., Cardiovas Res 23: 173, 1979). To evaluate the long-term effects of this antihypertensive agent, the drug was administered to SHR and normotensive (WKY) rats between the ages of 1 and 12 months. In another group of SHR and WKY, treatment was delayed until the age of 12 months and the animals were then treated for 3 months. Treatment with alpha-methyldopa had similar effects on systolic blood pressures in both SHR groups; group means (+/- SEM) were 151 +/- 1 in the long-term treatment group and 157 +/- 5 in the delayed treatment group compared to 178 +/- 4 and 176 +/- 3 for their respective controls. While left ventricular weight and cell size were significantly lower after early long-term treatment (compared to nontreated SHR), delayed treatment had no significant effect on these indices of left ventricular mass. Despite the effectiveness of early long-term treatment in modifying left ventricular mass, the relative volumes of mitochondria and myofibrils, as well as other cellular components (sarcoplasm), were not altered. In contrast, delayed treatment caused a significant increase (approximately twofold) in relative sarcoplasmic volume and a decrease in relative myofibrillar volume in both SHR and WKY. These findings indicate that shifts in the relative volumes of intracellular components after alpha-methyldopa are independent of cell size and blood pressure. Furthermore, the data suggest that the effects of alpha-methyldopa on the myocardial cell are dependent on or influenced by factors associated with the development or stabilization of hypertrophy and/or age.
R J Tomanek
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Hypertension     Volume:  4     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:    1982 Jul-Aug
Date Detail:
Created Date:  1983-03-17     Completed Date:  1983-03-17     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  499-506     Citation Subset:  IM    
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MeSH Terms
Blood Pressure / drug effects
Captopril / pharmacology
Cell Compartmentation / drug effects
Hydralazine / pharmacology
Hypertension / drug therapy,  pathology*
Methyldopa / pharmacology*
Mitochondria, Heart / drug effects
Myocardium / pathology*,  ultrastructure
Myofibrils / drug effects
Rats, Inbred Strains
Grant Support
Reg. No./Substance:
555-30-6/Methyldopa; 62571-86-2/Captopril; 86-54-4/Hydralazine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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