Chiaki Nakamura; Iwao Sato; Yoko Ueda; Shinichi Kawata; Kenta Nagahori; Takuya Omotehara; Tomiko Yakura; Zhong-Lian Li & Masahiro Itoh

Neuropeptide calcitonin gene-related peptide (CGRP) is a neurotransmitter related to vasculogenesis during organ development. The vascular endothelial growth factor A (VEGF-A) is also required for vascular patterning during lung morphogenesis. CGRP is primarily found in organs and initially appears in pulmonary neuroendocrine cells during the early embryonic stage of lung development. However, the relationship between CGRP and VEGF-A during lung formation remains unclear. This study investigates CGRP and VEGF-A mRNA expressions in the embryonic, pseudoglandular, canalicular, saccular, and alveolar stages of lung development from embryonic day 12.5 (E12.5) to postnatal day 5 (P5) through quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. Further, we analyzed the expression of CGRP via immunohistochemistry. The VEGF-A mRNA was mainly scattered across the whole lung body from E12.5. CGRP was found to be expressed in a few epithelial cells of the canalicular and the respiratory bronchiole of the lung from E12.5 to P5. An antisense probe for CGRP mRNA was strongly detected in the lung from E14.5 to E17.5. Endogenous CGRP may regulate the development of the embryonic alveoli from E14.5 to E17.5 in a temporal manner.

KEY WORDS: Neurotransmitter; Calcitonin gene-related peptide; Vasculogenesis, Embryonic, postnatal; In situ hybridization.

NAKAMURA, C.; SATO, I.; UEDA, Y.; KAWATA, S.; NAGAHORI, K.; OMOTEHARA, T.; YAKURA, T.; LI, Z. L. & ITOH, M. Distribution of calcitonin gene-related peptide and vascular endothelial growth factor in the mouse lung at the embryonic and postnatal stages. Int. J. Morphol., 41(1):45-50, 2023.