ABSTRACT
BACKGROUND: Calcitonin gene-related peptide (CGRP) and substance P (SP) play counter-regulatory roles in coronary flow. This study is to assess whether effects of CGRP and SP are gender-specific. METHODS: Langendorff-perfused hearts were used to compare coronary flow rates among 119 wild-type, alpha-CGRP and SP receptor knockout mice under various perfusion pressures (20, 30, 40, 50 mmHg). RESULTS: For mouse heart coronary flow rate, deletion of alpha-CGRP gene resulted in significant reduction for both genders at all pressures; female CGRP knockout showed 15.3% reduction (P < .01); male CGRP knockout showed 13.8% reduction (P < .01); no significant difference between male and female CGRP knockout; female SP receptor knockout showed 13.9% increase (P < .01); female SP receptor knockout had a greater percentage decrease than male (P < .01). CONCLUSIONS: CGRP plays similar roles as a vasodilator in males and females. SP seems to act as a vasoconstrictor in females.
