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Cells expressing angiotensin II receptors in fibrous tissue of rat heart.
Cardiovasc Res. 1996 Apr; 31(4):518-25.CR

Abstract

OBJECTIVE

Following left coronary artery ligation, markedly increased angiotensin II (AngII) receptor binding appears at the site of myocardial infarction (MI). This is also true for the fibrosed visceral pericardium in rats following pericardiotomy (with or without MI). Cells expressing AngII receptors at these sites remain unknown. In the present study, we sought to identify cells expressing AngII receptors at these sites of fibrosis in the rat heart during both early and late stages of wound healing.

METHODS

MI was created by left coronary artery ligation. Sham operation included thoracotomy, pericardiotomy and placement of silk ligature around the left coronary artery without MI. Hearts were collected at postoperative week 1 and 4. In serial sections: autoradiography (125I[Sar1,Ile8]AngII) was used to determine cells expressing AngII receptors; hematoxylin-eosin and alpha smooth muscle actin were used for identification of cell morphology and phenotype, respectively; and picrosirius red for identification of fibrillar collagen.

RESULTS

(1) at week 1, necrotic tissue at the site of MI was surrounded by granulation tissue that included macrophages, alpha smooth muscle actin fibroblast-like cells, or myofibroblasts, fibrillar collagen, and new vessels; (2) at week 4, scar tissue had formed and remaining cells were primarily myofibroblasts; (3) pericardial fibrosis was evident at weeks 1 and 4 and contained myofibroblasts, not macrophages or new vessels; (4) at week 1 and 4 myofibroblasts were the predominant cell expressing high-density AngII receptors at the site of MI, while fibroblasts, macrophages and vessels demonstrated low-density AngII receptor binding; and (5) at weeks 1 and 4, myofibroblasts express high-density AngII receptor binding in pericardial fibrosis.

CONCLUSION

In a rat model of tissue repair involving either MI or pericardial fibrosis, increased AngII receptor expression is primarily associated with myofibroblasts. This suggests AngII may play a role in mediating the fibrogenic response provided by this wound healing cell at sites of tissue injury in the rat heart.

Authors+Show Affiliations

Department of Internal Medicine, University of Missouri Health Sciences Center, Columbia 65212, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8689643

Citation

Sun, Y, and K T. Weber. "Cells Expressing Angiotensin II Receptors in Fibrous Tissue of Rat Heart." Cardiovascular Research, vol. 31, no. 4, 1996, pp. 518-25.
Sun Y, Weber KT. Cells expressing angiotensin II receptors in fibrous tissue of rat heart. Cardiovasc Res. 1996;31(4):518-25.
Sun, Y., & Weber, K. T. (1996). Cells expressing angiotensin II receptors in fibrous tissue of rat heart. Cardiovascular Research, 31(4), 518-25.
Sun Y, Weber KT. Cells Expressing Angiotensin II Receptors in Fibrous Tissue of Rat Heart. Cardiovasc Res. 1996;31(4):518-25. PubMed PMID: 8689643.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Cells expressing angiotensin II receptors in fibrous tissue of rat heart. AU - Sun,Y, AU - Weber,K T, PY - 1996/4/1/pubmed PY - 1996/4/1/medline PY - 1996/4/1/entrez SP - 518 EP - 25 JF - Cardiovascular research JO - Cardiovasc Res VL - 31 IS - 4 N2 - OBJECTIVE: Following left coronary artery ligation, markedly increased angiotensin II (AngII) receptor binding appears at the site of myocardial infarction (MI). This is also true for the fibrosed visceral pericardium in rats following pericardiotomy (with or without MI). Cells expressing AngII receptors at these sites remain unknown. In the present study, we sought to identify cells expressing AngII receptors at these sites of fibrosis in the rat heart during both early and late stages of wound healing. METHODS: MI was created by left coronary artery ligation. Sham operation included thoracotomy, pericardiotomy and placement of silk ligature around the left coronary artery without MI. Hearts were collected at postoperative week 1 and 4. In serial sections: autoradiography (125I[Sar1,Ile8]AngII) was used to determine cells expressing AngII receptors; hematoxylin-eosin and alpha smooth muscle actin were used for identification of cell morphology and phenotype, respectively; and picrosirius red for identification of fibrillar collagen. RESULTS: (1) at week 1, necrotic tissue at the site of MI was surrounded by granulation tissue that included macrophages, alpha smooth muscle actin fibroblast-like cells, or myofibroblasts, fibrillar collagen, and new vessels; (2) at week 4, scar tissue had formed and remaining cells were primarily myofibroblasts; (3) pericardial fibrosis was evident at weeks 1 and 4 and contained myofibroblasts, not macrophages or new vessels; (4) at week 1 and 4 myofibroblasts were the predominant cell expressing high-density AngII receptors at the site of MI, while fibroblasts, macrophages and vessels demonstrated low-density AngII receptor binding; and (5) at weeks 1 and 4, myofibroblasts express high-density AngII receptor binding in pericardial fibrosis. CONCLUSION: In a rat model of tissue repair involving either MI or pericardial fibrosis, increased AngII receptor expression is primarily associated with myofibroblasts. This suggests AngII may play a role in mediating the fibrogenic response provided by this wound healing cell at sites of tissue injury in the rat heart. SN - 0008-6363 UR - https://www.unboundmedicine.com/medline/citation/8689643/Cells_expressing_angiotensin_II_receptors_in_fibrous_tissue_of_rat_heart_ L2 - https://medlineplus.gov/heartattack.html DB - PRIME DP - Unbound Medicine ER -