Angiotensin II receptor blockade in Syrian hamster (T0-2) cardiomyopathy does not affect microscopic cardiac material properties: implications for mechanisms of tissue remodeling.
This study delineates the role of angiotensin II type I (AT1) receptor in the remodeling of Syrian cardiomyopathic hamsters. Twelve cardiomyopathic (T0-2) hamsters received L-158,809 treatment and libitum in their drinking water (27 micrograms/ml) and 9 cardiomyopathic and 9 normal FL-B hamsters received tap water from 1 to 4 months of age. Although pharmacologically effective with regard to complete suppression of the blood pressure response to angiotensin II infusion, L-158,809 did not diminish the progression or severity of cardiomyopathy. Heart weight/100 g body weight and left ventricular wall thickness adjusted for body weight of both L-158,809 and cardiomyopathic control hamsters did not differ and exceeded those of F1-B controls (p < 0.05). Myocardial material properties (e.g., stiffness and density) of cardiomyopathic hamsters treated with L-158,809 were not affected. Thus, the progression of fibrosis, calcification, and necrosis in T0-2 cardiomyopathic hamsters was not sensitive to AT1 receptor blockade.
Lanza
G M
GM
Jewish Hospital, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Scott
M J
MJ
Davison
G
G
Hall
C S
CS
Christy
D H
DH
Miller
J G
JG
Wickline
S A
SA
D000804:Angiotensin II / Q000494:pharmacology; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D006224:Cricetinae; D004452:Echocardiography; D006321:Heart / Q000187:drug effects*; D007093:Imidazoles / Q000627:therapeutic use*; D008297:Male; D008647:Mesocricetus; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D009929:Organ Size; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000502:physiology; D013777:Tetrazoles / Q000627:therapeutic use*
D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D007093:Imidazoles; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D013777:Tetrazoles; D000804:Angiotensin II; C070967:L 158809; D003094:Collagen