Interleukin 1-beta (IL-1beta) enhances contractile responses in endothelium-denuded aorta from hypertensive, but not normotensive, rats.
BACKGROUND
The chronic effects of interleukin 1-beta (IL-beta) on vascular reactivity include augmentation of contraction and relaxation. Few studies have assessed the acute effects of IL-1beta in vessels from hypertensive and normotensive rats. We hypothesized that IL-1beta would enhance constriction in aorta from stroke prone spontaneously hypertensive rats (SHRSP).


METHODS
Endothelium denuded aortic rings from 12 week-old SHRSP and Wistar Kyoto (WKY) rats were mounted in a myograph and incubated with IL-1beta (20 ng/ml) for 1 h before construction of a phenylephrine dose response curve. Indomethacin (1 microM) and PP-2 (1 microM) were utilized to inhibit cyclooxygenase (COX) and Src-kinase respectively.


RESULTS
In aorta from SHRSP, IL-1beta caused a significant increase in the force generated over the hour incubation; inhibition of COX or Src-kinase prevented this. The maximum phenylephrine-induced contraction was greater in aorta from SHRSP incubated with IL-1beta than control. COX or Src-kinase inhibition prevented this. IL-1beta had no effect on the vessels from WKY rats.


CONCLUSIONS
These novel data suggest that IL-1beta has rapid effects on vascular smooth muscle from hypertensive rats to produce constriction and to enhance phenylephrine-induced constriction. The COX and Src-kinase pathways appear to be involved in this response.
Dorrance
Anne M
AM
Department of Physiology, Medical College of Georgia, Augusta, GA 30912-3000, USA. adorrance@mcg.edu
D000818:Animals; D001013:Aorta, Thoracic / Q000503:physiopathology*; D004195:Disease Models, Animal; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D007213:Indomethacin; D053583:Interleukin-1beta / Q000502:physiology*; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology; D009213:Myography; D010656:Phenylephrine / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects / Q000378:metabolism; D011743:Pyrimidines; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D019061:src-Family Kinases / Q000187:drug effects / Q000378:metabolism
C412373:AG 1879; D053583:Interleukin-1beta; D011743:Pyrimidines; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D011451:Prostaglandin-Endoperoxide Synthases; D019061:src-Family Kinases; D007213:Indomethacin