Vasculogenesis by Endothelial Progenitor Cells In Vitro

The present study investigated the arrangement and chemical coding of intramural nerve structures supplying the porcine stomach. Tissue samples comprising all layers of the wall of the ventricular fundus were collected from juvenile female pigs ( n  = 4), which were first deeply anaesthetized and then transcardially perfused with buffered paraformaldehyde. The cryostat sections were processed for double-labelling immunofluorescence to study the distribution of the intramural nerve structures (visualized with antibodies against protein gene-product 9.5) and their neurochemical characteristics using antibodies against vesicular acetylcholine transporter (VAChT), nitric oxide synthase (NOS), galanin (GAL), vasoactive intestinal-polypeptide (VIP), somatostatin (SOM) and substance P (SP). The study confirmed the presence of three distinct nerve plexuses within the wall of the porcine stomach including one myenteric plexus and two, outer and inner, submucous plexuses. The outer and inner submucous plexuses (OSP and ISP, respectively) were similar in respect to the chemical coding of neurons they contained. Most of the neurons expressed immunoreactivity to SP (ISP 58%; OSP 60%) or to VAChT (ISP 56%; OSP 56%), some of them stained for GAL (ISP 18%; OSP 15%) and solitary nerve cells were SOM-positive (in ISP only). No neurons in the submucous plexuses displayed immunoreactivity to VIP or NOS. In the myenteric plexus, some neurons stained for NOS (20%), VAChT (15%), GAL (10%), VIP (8%) or SP (8%) while no neurons immunoreactive for SOM were encountered. In both submucous and myenteric plexuses, many varicose nerve fibres expressed immunoreactivity to VAChT, GAL or SP, while VIP-, SOM- or NOS-positive nerve terminals were less numerous. The comparison of the present results with those obtained by other authors has revealed distinct inter-species differences regarding the arrangement and chemical coding of nerve structures supplying the mammalian stomach.