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Allergic sensitization increases contractile responses to 5-HT in guinea pig aorta
P Campos-Bedolla1, R De-La-Cruz-Negrete, M H Vargas
1Unidad de Investigación Médica en Enfermedades Neurológicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México. camposbedollap@hotmail.com.
Physiological Research
|December 20, 2019
Summary
Allergic sensitization in guinea pigs enhances 5-hydroxytryptamine (5-HT) induced aortic contractions, suggesting asthma impacts cardiovascular function. However, this effect is not linked to changes in 5-HT2A receptor expression.
Area of Science:
- Cardiovascular Physiology
- Pulmonary Medicine
- Pharmacology
Background:
- Asthma is linked to adverse cardiovascular outcomes, but underlying mechanisms remain unclear.
- 5-Hydroxytryptamine (5-HT) plays a role in both asthma pathophysiology and cardiovascular regulation.
- Investigating the interplay between allergic sensitization and vascular responses to 5-HT is crucial for understanding asthma's systemic effects.
Purpose of the Study:
- To determine if allergic sensitization alters 5-hydroxytryptamine (5-HT)-induced contractile responses in guinea pig thoracic aorta rings.
- To examine the effect of sensitization on 5-HT2A receptor expression in the thoracic aorta.
- To elucidate the role of 5-HT2A receptors in the altered vascular contractility observed in a guinea pig asthma model.
Main Methods:
- Guinea pigs were subjected to an allergic sensitization protocol.
- Thoracic aorta rings were isolated and subjected to contractile response assays with 5-HT.
- Quantitative PCR (qPCR) and Western blot analysis were used to assess 5-HT2A receptor mRNA and protein expression.
Main Results:
- Allergic sensitization significantly increased 5-HT-induced contractions in aorta rings by approximately 27% compared to non-sensitized controls (p<0.05).
- Preincubation with ketanserin, a 5-HT2A receptor antagonist, reduced 5-HT-induced contractions in both sensitized and non-sensitized animals, indicating 5-HT2A receptor involvement.
- No significant differences in 5-HT2A receptor mRNA or protein expression were found between sensitized and non-sensitized guinea pigs.
Conclusions:
- Allergic sensitization in this guinea pig model extends beyond the airways, influencing arterial contractile responses to 5-HT.
- The enhanced 5-HT-induced aortic contractility in sensitized animals is not attributable to alterations in 5-HT2A receptor expression.
- These findings highlight a potential non-airway mechanism linking asthma to cardiovascular dysfunction.
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