Application of RT-PCR to Regional Mapping of B1- and B2-Adrenergic Receptor mRNAs in Rat Heart

Details

• Personal Author:
  Bourgeois F ; Hardouin S ; Moalic JM ; Oubenaissa A ; Swynghedauw B ; Toraason M
• Description:
  Chronotropic and inotropic activities of the heart are stimulated through B1- and B2- adrenergic receptors (AR). Regional distribution of B-ARs and corresponding mRNAs in the heart are not well defined despite the potential for molecular phenotypic redistribution to be a factor in pathological conditions. Investigating regional distribution of specific mRNAs in the rat have been hampered by the paucity of tissue and the low abundance in heart of B-ARs. Reverse transcription in combination with the polymerase chain reaction (RT-PCR) was used to measure the number of B1- and B2-AR Mrna molecules in the four chambers of rat heart. The right atria was microdissected into four sections with the SA node limited to subsection RA/1. RT-PCR resulted in single amplification products of expected sizes. cRNAs specific for B1- and B2-ARs but with restriction sites produced by punctual mutations were used as internal standards. The mean number of B1-AR mRNA molecules per ng of total RNA ranged from 663 +/- 75 to 918 +/- 90 in the ventricular and atrial regions. There was significantly more B1-AR mRNA in right atria than left atria or ventricles. Right atrial subsections RA/1 and RA/2 contained significantly more B1-AR mRNA than subsections RA/3 and RA/4. The number of B2/AR mRNA molecules ranged from 375 +/- 67 to 481 +/- 104 in the regions examined. The number of B2-AR mRNA molecules did not differ significantly among the chambers or subsections. The sums of B1- and B2-AR mRNAs among the individual chambers and atrial subsections were equivalent, but the B1/B2-AR mRNA ratios ranged from 1.45 +/- 0.08 to 2.49 +/- 0.22 and varied significantly. The highest ratio occurred in the right atria and the lowest in left ventricle. Within the right atria, subsection RA/1 exhibited the highest ratio which was significantly greater than subsection RA/3, but not subsections RA/2 or RA/4. Comparison of the above variables between adult (3 mo) and senescent (24 mo) rats revealed significant phenotypic remodeling of B-AR mRNA distribution throughout the myocardium. These changes could contribute to increased rhythm disturbances observed in senescent heart. [Description provided by NIOSH]
• Subjects:
  Animals Cardiovascular System Genetics Laboratories Occupational Health Safety
• Keywords:
  Animal-studies Cardiovascular-system Genes Heart Heart-rate Laboratory-animals
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DBBS - Division of Biomedical and Behavioral Sciences
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  30
• Issue:
  1
• NIOSHTIC Number:
  nn:20030651
• Citation:
  Toxicologist 1996 Mar; 30(1)(Pt 2):270
• Federal Fiscal Year:
  1996
• Peer Reviewed:
  False
• Part Number:
  2
• Source Full Name:
  The Toxicologist. Society of Toxicology 35th Annual Meeting, March 10-14,1996, Anaheim, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:daf5b093303f6ab515934d2f0a692573702b2a6a0bfd0507a922009ad91ddce97078488bc5e26b8a91c6e9e2b412d91263228f0c7fed81d6035cd74bb31a5b6c
• Download URL:
  https://stacks.cdc.gov/view/cdc/191192/cdc_191192_DS1.pdf
• File Type:
  [PDF - 134.54 KB ]