Effects of shearing stress on aortic histamine synthesis

• Published in: Experimental and molecular pathology Vol. 20; no. 1; pp. 1 - 10
• Main Authors: Hollis, Theodore M., Ferrone, Ronald A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.02.1974
• Subjects: Animals; Aorta, Thoracic - anatomy & histology; Aorta, Thoracic - enzymology; Aorta, Thoracic - metabolism; Blood Flow Velocity; Carboxy-Lyases - metabolism; Endothelium - metabolism; Histamine - biosynthesis; Histidine; In Vitro Techniques; Male; Perfusion; Rabbits
• ISSN: 0014-4800; 1096-0945
• DOI: 10.1016/0014-4800(74)90038-0

The potential of elevated shearing stresses imposed on the endothelial surface of rabbit thoracic aorta to increase aortic histamine synthesis through activation of aortic histidine decarboxylase (HD) has been examined. Using a Tyrodes-glycerine solution (37°C, pH 7.4, 3.5 centipoise) as the perfusion solution, aortas were subjected to shearing stresses of 8 (control), 27, and 800 dynes/cm 2, respectively. Additional nontreated and incubated controls were also used. The aortic HD activity, expressed as histamine forming capacity (HFC), for the three treatment groups were (in dpm/mg protein) 302 ± 10, 1537 ± 26, and 969 ± 16, respectively. Histological examination of similarly treated segments revealed no endothelium present in the 800 dynes/cm 2 stressed group. These data indicate that aortic histamine synthesis increased approximately 5-fold in response to a 3 1 2 - fold increase in shear exposure and that over 50% of the increase in histamine synthesis occurred in the endothelial monolayer. These data have been discussed both in relation to the role of the endothelium in regulation of, and the effects of histamine on, vascular wall permeability.