{"doi":"10.1111/micc.12808","title":"5‐HT<sub>7</sub> receptors mediate dilation of rat cremaster muscle arterioles in vivo","abstract":"Abstract Objective Serotonin (5‐HT) infusion in vivo causes hypotension and a fall in total peripheral resistance. However, the vascular segment and the receptors that mediate this response remain in question. We hypothesized that 5‐HT 7 receptors mediate arteriolar dilation to 5‐HT in skeletal muscle microcirculation. Methods Cremaster muscles of isoflurane‐anesthetized male Sprague‐Dawley rats were prepared for in vivo microscopy of third‐ and fourth‐order arterioles and superfused with physiological salt solution at 34°C. Quantitative real‐time PCR (RT‐PCR) was applied to pooled samples of first‐ to third‐order cremaster arterioles (2–4 rats/sample) to evaluate 5‐HT 7 receptor expression. Results Topical 5‐HT (1–10 nmols) or the 5‐HT 1/7 receptor agonist, 5‐carboxamidotryptamine (10–30 nM), dilated third‐ and fourth‐order arterioles, responses that were abolished by 1 μM SB269970, a selective 5‐HT 7 receptor antagonist. In contrast, dilation induced by the muscarinic agonist, methacholine (100 nmols) was not inhibited by SB269970. Serotonin (10 nmols) failed to dilate cremaster arterioles in 5‐HT 7 receptor knockout rats whereas arterioles in wild‐type litter mates dilated to 1 nmol 5‐HT, a response blocked by 1 μM SB269970. Quantitative RT‐PCR revealed that cremaster arterioles expressed mRNA for 5‐HT 7 receptors. Conclusions 5‐HT 7 receptors mediate dilation of small arterioles in skeletal muscle and likely contribute to 5‐HT‐induced hypotension, in vivo.","journal":"Microcirculation","year":2023,"id":374775,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9644,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1136729,"name":"Armond Daci","orcid":"0000-0003-1276-4561","position":1,"is_corresponding":false},{"id":795956,"name":"Janice Thompson","orcid":"0000-0002-1669-409X","position":2,"is_corresponding":false},{"id":417735,"name":"Gregory D. Fink","orcid":"0000-0003-4099-986X","position":3,"is_corresponding":false},{"id":321596,"name":"Stephanie W. Watts","orcid":"0000-0002-9653-6357","position":4,"is_corresponding":false},{"id":937834,"name":"William F. Jackson","orcid":"0000-0002-9657-0141","position":0,"is_corresponding":true}],"reference_count":35,"raw_metadata":null,"created_at":"2026-07-19T01:16:15.380731Z","pmid":"37204759","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}