Enalapril alters the formation of the collagen matrix in spontaneously hypertensive rats.
OBJECTIVE
To assess the effect of the inhibition of the angiotensin-converting enzyme on the collagen matrix (CM) of the heart of newborn spontaneously hypertensive rats (SHR) during embryonic development.


METHODS
The study comprised the 2 following groups of SHR (n=5 each): treated group - rats conceived from SHR females treated with enalapril maleate (15 mg. kg-1.day-1) during gestation; and nontreated group - offspring of nontreated females. The newborns were euthanized within the first 24 hours after birth and their hearts were removed and processed for histological study. Three fields per animal were considered for computer-assisted digital analysis and determination of the volume densities (Vv) of the nuclei and CM. The images were segmented with the aid of Image Pro Plus  4.5.029 software (Media Cybernetics).


RESULTS
No difference was observed between the treated and nontreated groups in regard to body mass, cardiac mass, and the relation between cardiac and body mass. A significant reduction in the Vv[matrix] and a concomitant increase in the Vv[nuclei] were observed in the treated group as compared with those in the nontreated group.


CONCLUSIONS
The treatment with enalapril of hypertensive rats during pregnancy alters the collagen content and structure of the myocardium of newborns.
Bomfim
Alfredo de Souza
Ade S
Instituto de Biologia Roberto Alcântara Gomes, UERJ, Rio de Janeiro, RJ, Brazil. abomfim@unisys.bom.br
Mandarim-de-Lacerda
Carlos Alberto
CA
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D003094:Collagen / Q000187:drug effects* / Q000378:metabolism; D004656:Enalapril / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000187:drug effects*; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000196:embryology; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR
D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril; D003094:Collagen