title: Muscarinic receptors and their mRNAs in type 2 Goto-Kakizaki diabetic rat prostate.
abstract: BACKGROUND
  As increasing evidence is pointing towards the relationship between diabetes and benign prostatic hyperplasia/lower urinary tract symptoms, we investigated the pharmacological properties and gene expressions of the muscarinic receptors in type 2 diabetes rat prostate.
  
  
  METHODS
  Twelve- and 70-week-old male Goto-Kakizaki (GK) rats and age-matched male Wistar rats were used in this study. The densities of muscarinic receptors (B(max) values) were determined by saturation studies with [(3)H]NMS ([N-methyl-(3)H] scopolamine methyl chloride) in the prostatic membrane particulates. The participation levels of M(1), M(2), and M(3) receptor protein and mRNA levels in the prostate were investigated by immunoblot analysis and real-time polymerase chain reaction (PCR), respectively.
  
  
  RESULTS
  The B(max) values in 12-week-old Wistar and GK, and in 70-week-old Wistar and GK rat prostates were 36.0 +/- 2.8, 49.4 +/- 11.4, 22.0 +/- 2.2, and 47.0 +/- 4.1 fmol/mg protein, respectively. However, there were no significant differences in the affinity constants between any groups. Immunoblot analysis showed the existence of significant amounts of M(1), M(2), and M(3) receptor subtypes in each rat prostate. According to real-time PCR studies the rank order of expression levels of muscarinic receptors mRNA subtypes in the prostate were M(3) > M(2) > M(1). In each receptor subtype in each group, diabetes induced up-regulation of mRNAs while the advanced age of the rats was related with down-regulation of mRNAs.
  
  
  CONCLUSIONS
  Our data indicated that type 2 diabetes induced up-regulation and age-related down-regulation of the expressions of muscarinic receptors and their mRNAs in the rat prostate.
authors.affiliation: Department of Pathophysiological and Therapeutic Science, Division of Molecular Pharmacology, Tottori University School of Medicine, Yonago, Japan. saitomo@med.tottori-u.ac.jp
authors.forename: Motoaki
authors.initials: M
authors.lastname: Saito
authors.forename: Emi
authors.initials: E
authors.lastname: Kazuyama
authors.forename: Shogo
authors.initials: S
authors.lastname: Shimizu
authors.forename: Fotios
authors.initials: F
authors.lastname: Dimitriadis
authors.forename: Yukako
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Eiji
authors.initials: E
authors.lastname: Masuda
authors.forename: Shizuo
authors.initials: S
authors.lastname: Yamada
authors.forename: Keisuke
authors.initials: K
authors.lastname: Satoh
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000235:genetics*; D015151:Immunoblotting; D007328:Insulin / Q000097:blood; D008297:Male; D019832:N-Methylscopolamine / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011467:Prostate / Q000503:physiopathology*; D011470:Prostatic Hyperplasia / Q000150:complications / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D043643:Receptor, Muscarinic M1 / Q000235:genetics / Q000378:metabolism; D043585:Receptor, Muscarinic M2 / Q000235:genetics / Q000378:metabolism; D043587:Receptor, Muscarinic M3 / Q000235:genetics / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000235:genetics* / Q000378:metabolism; D013739:Testosterone / Q000097:blood
chemical_list: D001786:Blood Glucose; D007328:Insulin; D012333:RNA, Messenger; D043643:Receptor, Muscarinic M1; D043585:Receptor, Muscarinic M2; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic; D013739:Testosterone; D019832:N-Methylscopolamine