Alterations in levels of vascular histamine in the DOCA-hypertensive rat

1. Histamine was detected in the abdominal aorta and the femoral arteries of normotensive and also DOCA-hypertensive rats. 2. Levels of total histamine (mast cell and non-mast cell histamine) were significantly reduced in both abdominal aorta and the femoral artery of the DOCA-hypertensive rats, relative to the normotensive controls. 3. It is suggested that the diminished level of vascular histamine may be related to the development and/or maintenance of the hypertensive state and is also related to the reduced magnitude of active reflex vasodilatation.