Distribution of 3H-nitrendipine in the isolated perfused rat heart as revealed by electron microscopic autoradiography

Muhammad Ashraf, Won Hark Park, Ingrid Grupp, Arnold Schwartz

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Subcellular distribution of 3H-nitrendipine was investigated in the isolated perfused rat heart by means of electron microscopic autoradiography. Mechanical measurements of cardiac contractile activity (dP/dt) were performed on the hearts used for autoradiography. There was a non-random pattern of silver grain distribution over the myocardial cells. The grain density, i.e. percentage of total grains/percentage of cell area, was determined for each cell component. A grain density higher than one was noted on the cell membrane, T-tubules and capillaries, indicating a significant incorporation of 3H-nitrendipine into the structures. Concentrations of unlabeled nitrendipine containing radiolabeled nitrendipine caused increased grain density and a decreased contractile activity (dP/dt) by 6% to 30%. It is therefore possible that the pharmacological action of nitrendipine is associated with the localization of 3H-nitrendipine on or in the cell membrane, T-tubules and capillaries.

Original languageEnglish (US)
Pages (from-to)265-272
Number of pages8
JournalJournal of molecular and cellular cardiology
Issue number3
StatePublished - Mar 1986
Externally publishedYes


  • Autoradiography
  • Calcium antagonist
  • H-nitrendipine
  • Membranes
  • Nitrendipine
  • T-tubules

ASJC Scopus subject areas

  • Molecular Biology
  • Cardiology and Cardiovascular Medicine


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