Changes of the expression of insulin-like growth factor 1 and its two receptors in the periphery of the developing lung are parallel to ultrastructural capillary changes during perinatal period

Abstract

AbstractInsulin-like growth factor type 1 (IGF-1) belongs to the peptide hormones which regulate cell proliferation and differentiation as well as angiogenesis.The aim of the present study was the quantitative evaluation of immuohistochemical (IH) expression of IGF-1 and its two receptors (IGF-1Rα and IGF-1Rβ) parallel to changes of capillary lumen/whole capillary area (L/W) ratio during the perinatal period.Tissue samples from lungs from 19-, and 21-day fetuses as well as 1-, 3-, 5-day old newborns were processed for frozen sections that were used for IH staining and then used for quantitative analysis of antigens expression. In parallel, tissue samples were processed for transmission electron microscopy and used for capillaries morphometry. Our results were statistically evaluated.We found that the expression of IGF-1 in the peripheral part of the developing lung has a peak at the moment of birth when changes of vascular structure were reflected by L/W ratio. This is followed by the peak expression of the IGF-1Rα, but not of the IGF-1Rβ.