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Short-Duration Hypothermia Induction in Rats using Models for Studies examining Clinical Relevance and Mechanisms
Published on: March 3, 2021
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Hypothermia Inhibits Dexmedetomidine-Induced Contractions in Isolated Rat Aortae
Soohee Lee1,2,3, Yeran Hwang4, Kyeong-Eon Park4
1Department of Anesthesiology and Pain Medicine, Gyeongsang National University Changwon Hospital, Changwon-si 51472, Gyeongsangnam-do, Republic of Korea.
International Journal of Molecular Sciences
|March 13, 2024
Summary
Hypothermia significantly reduces dexmedetomidine-induced aortic contraction by hindering calcium influx and partially attenuating protein kinase C (PKC) and Rho-kinase pathways. Recovery to normothermia reversed these effects.
Area of Science:
- Pharmacology
- Cardiovascular Physiology
- Cellular Signaling
Background:
- Dexmedetomidine is a common sedative in perioperative care.
- Hypothermia is a potential complication during surgery.
- The interaction between hypothermia and dexmedetomidine's effects on vascular tone is not fully understood.
Purpose of the Study:
- To investigate the impact of hypothermia on dexmedetomidine-induced aortic contraction.
- To elucidate the underlying mechanisms, including the roles of nitric oxide synthase, calcium influx, and intracellular signaling pathways.
Main Methods:
- Experiments were conducted on isolated rat aortas (endothelium-intact and -denuded).
- Vascular contractions were measured under varying temperatures (33 °C and 25 °C).
- Involvement of nitric oxide synthase, calcium, protein kinase C (PKC), and Rho-kinase was assessed.
Main Results:
- Hypothermia inhibited dexmedetomidine-induced contraction in endothelium-intact and -denuded aortas.
- Inhibition was primarily linked to impaired calcium influx, with partial attenuation of PKC and Rho-kinase activation.
- Reversal of hypothermia to normothermia restored vascular responsiveness.
Conclusions:
- Hypothermia significantly impairs dexmedetomidine-mediated vasoconstriction.
- The primary mechanism involves reduced calcium influx, with secondary contributions from PKC and Rho-kinase pathways.
- These findings have implications for managing patients receiving dexmedetomidine during hypothermic conditions.
