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Updated: Oct 19, 2025
Detection and Quantification of Calcitonin Gene-Related Peptide CGRP in Human Plasma Using a Modified Enzyme-Linked Immunosorbent Assay
Published on: June 16, 2023
Calcitonin Gene Related Peptide, Adrenomedullin, and Adrenomedullin 2 Function in Uterine Artery During Human
Madhu Chauhan1, Ancizar Betancourt1, Meena Balakrishnan1
1Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030, USA.
Rationale:
Calcitonin gene-related peptide (CGRP) and its family members adrenomedullin (ADM) and adrenomedullin 2 (ADM2; also known as intermedin) support vascular adaptions in rat pregnancy.
Objective:
This study aimed to assess the relaxation response of uterine artery (UA) for CGRP, ADM, and ADM2 in nonpregnant and pregnant women and identify the involved mechanisms.
Findings:
(1) Segments of UA from nonpregnant women that were precontracted with U46619 (1μM) in vitro are insensitive to the hypotensive effects of CGRP, ADM, and ADM2; (2) CGRP, ADM, and ADM2 (0.1-100nM) dose dependently relax UA segments from pregnant women with efficacy for CGRP > ADM = ADM2; (3) the relaxation responses to CGRP, ADM, and ADM2 are differentially affected by the inhibitors of nitric oxide (NO) synthase (L-NAME), adenylyl cyclase (SQ22536), apamin, and charybdotoxin; (4) UA smooth muscle cells (UASMC) express mRNA for calcitonin receptor-like receptor (CRLR) and receptor activity modifying protein (RAMP)1 and RAMP2 but not RAMP3; (5) receptor heterodimer comprising CRLR/RAMP1 and CRLR/RAMP2 but not CRLR/RAMP3 is present in UA; (6) soluble fms-like tyrosine kinase (sFLT-1) and TNF-α treatment decrease the expression of RAMP1 mRNA (P < 0.05) in UASMC; and (7) sFLT-1 treatment impairs the association of CRLR with all 3 peptides while TNF-α inhibits the interaction of CGRP but not ADM or ADM2 with CRLR in UASMC (P < 0.05).
Conclusions:
Relaxation sensitivity of UA for CGRP, ADM, and ADM2 is increased during pregnancy via peptide-specific involvement of NO system and endothelium-derived hyperpolarizing factors; vascular disruptors such as sFLT-1 and TNFα adversely impact their receptor system in UASMC.
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