Abstract
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 language | English (US) |
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Pages (from-to) | 265-272 |
Number of pages | 8 |
Journal | Journal of molecular and cellular cardiology |
Volume | 18 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1986 |
Externally published | Yes |
Keywords
- Autoradiography
- Calcium antagonist
- H-nitrendipine
- Membranes
- Nitrendipine
- T-tubules
ASJC Scopus subject areas
- Molecular Biology
- Cardiology and Cardiovascular Medicine