Pentaerythrityl tetranitrate attenuates structural changes in conduit arteries evoked by long‐term NO‐synthase inhibition

The aim of the study was to determine whether the pentaerythrityl tetranitrate (PETN), a tolerance devoid exogenous NO donor could prevent morphological changes in the cardiovascular system evoked by long‐term NO‐synthase inhibition. Three groups of 10‐week‐old Wistar rats were used: (1) controls, (2) treated by L‐NG‐nitroarginine methyl ester (L‐NAME) in water (50 mg kg−1), and (3) treated by L‐NAME (50 mg kg−1 in water)+PETN (2×50 mg kg−1, using gavage). Blood pressure (BP) was measured by the tail plethysmographic method. After sacrificing the animals were perfused (120 mmHg) by glutaraldehyde fixative and processed according to standard electron microscopy procedure. Wall thickness (WT), cross sectional area (CSA), inner diameter (ID) of thoracic aorta (TA), carotid (CA) and septal branch of the left descending coronary artery (RS) were measured in light microscopy. After 6 weeks, the BP was increased to 172±1.7 mmHg (P