Key Points
- This research aims to evaluate the role of mesenteric arcade arteries in regulating vascular resistance in conscious rats.
- Determined intravascular pressure at the base of mesenteric arcades using catheters in conscious, unrestrained rats.
- Conducted acute pharmacological experiments with serotonin, noradrenaline, and angiotensin-II.
- Measured changes in the pressure ratios (Pmes/Psys) under different conditions.
- Under anaesthesia, Pmes/Psys was 86% initially but fell to 69% after recovery as systemic pressure increased.
- Serotonin injection caused Pmes/Psys to drop dramatically from 67% to 27%, while noradrenaline had no effect on this ratio despite a 30% rise in Psys.
- Angiotensin-II increased Psys by 38% and transiently raised Pmes/Psys to 86%, showing varying contributions of the arcade vessels.
Structured PICO
PPopulationConscious, unrestrained, resting rats
IInterventionIntravascular pressure measurement at the base of mesenteric arcades and acute pharmacological injections (serotonin, noradrenaline, angiotensin-II)
OOutcomeIntravascular pressure at the base of mesenteric arcades (P_mes) relative to systemic pressure (P_sys)surrogate
In conscious rats, mesenteric arcade arteries contribute substantially to the control of peripheral vascular resistance, with variable responses to different vasoactive agents.