title: Angiotensin II enhances glomerular expression of a nonmuscle myosin heavy chain, SMemb, with extracellular matrix accumulation.
abstract: OBJECTIVE
  We previously showed that the mesangial expression of nonmuscle-type myosin heavy chain, SMemb, was related to glomerular sclerosis. Although angiotensin II (AII) is known to promote the glomerular accumulation of extracellular matrix and sclerosis, the effect of AII on the mesangial expression of SMemb is unknown. Thus, we investigated the effect of AII on the mesangial expression of SMemb and synthesis of fibronectin.
  
  
  METHODS
  We continuously administered AII to Sprague-Dawley rats with subcutaneous osmotic minipumps for 14 days. Control animals received normal saline instead. The effects of oral administration of an AII type 1 (AT1) receptor antagonist, candesartan cilexetil, and a vasodilator, hydralazine, were also examined.
  
  
  RESULTS
  Semiquantitative immunohistochemical evaluation and Western blot analysis showed that AII significantly enhanced glomerular expression of SMemb (0.87 +/- 0.33 vs. 0.40 +/- 0.19 for immunohistochemical grading, p < 0.05; 2.55 +/- 0.88 vs. 1.16 +/- 0.75 for Western blot analysis, p < 0.05). Glomerular fibronectin was also increased in AII-administered rats (301.7 +/- 206.8 ng/5 microg protein vs. 95.8 +/- 81.3 ng/5 microg protein, p < 0.05). Candesartan cilexetil attenuated these effects. On the other hand, hydralazine did not change the glomerular expression of SMemb enhanced by AII administration.
  
  
  CONCLUSIONS
  All induced a phenotypic alteration in mesangial cells, enhanced the mesangial expression of SMemb and stimulated the fibronectin synthesis. These results suggest that the mesangial expression of SMemb is related to glomerular matrix accumulation and that AII mediates both mesangial processes via AT1 receptors.
authors.affiliation: Second Department of Internal Medicine, Faculty of Medicine, Gunma University, Maebashi, Japan.
authors.forename: Naobumi
authors.initials: N
authors.lastname: Mise
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kimura
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
authors.forename: Ryozo
authors.initials: R
authors.lastname: Nagai
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Okuda
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Ohba
authors.forename: Naoe
authors.initials: N
authors.lastname: Suzuki
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Miyashita
authors.forename: Atsuko
authors.initials: A
authors.lastname: Kamijo
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tojo
authors.forename: Atsuo
authors.initials: A
authors.lastname: Goto
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
mesh_terms: D000804:Angiotensin II / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001483:Base Sequence; D001794:Blood Pressure / Q000187:drug effects; D005109:Extracellular Matrix / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D015918:Infusion Pumps, Implantable; D007678:Kidney Glomerulus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism*; D024501:Nonmuscle Myosin Type IIB; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin / Q000378:metabolism
chemical_list: D005353:Fibronectins; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D024501:Nonmuscle Myosin Type IIB; C103815:nonmuscle myosin type IIB heavy chain; D018995:Myosin Heavy Chains