Ontogeny of substance P in the digestive tract, spinal cord and hypothalamus of the human fetus.
The time of appearance and tissue concentrations of substance P-like immunoreactivity (SP-LI) were studied in 53 human fetuses aged 8-21 weeks. Detectable amounts were present at 8 weeks of gestation in available fragments of spinal cord and intestine. Thereafter, the tissue concentrations were highest in spinal cord, intermediate in hypothalamus and lowest in digestive tract. Except for a significant increase in the intestinal wall, the concentrations did not vary from the 8-14 to the 15-21 week period. At chromatography, SP-LI in extracts of spinal cord and intestine was essentially eluted in the volume of the synthetic undecapeptide. Using the indirect immunofluorescence technique, the localization of SP-LI positive structures in the digestive tract was studied in 5 fetuses aged 12-18 weeks. Scarce cell bodies were observed in the myenteric plexus. Nerve fibers were recognized in the muscular layer, in the myenteric plexus and in connective tissue of pancreas. The present results demonstrate the early appearance of SP-LI positive structures both in central nervous system and in the enteric nervous system in the human fetus. In the age range tested, SP-LI concentrations were noticeably higher in spinal cord and hypothalamus than in the digestive tract.
D004064:Digestive System / Q000032:analysis* / Q000196:embryology; D005314:Embryonic and Fetal Development; D005333:Fetus / Q000032:analysis* / Q000502:physiology; D006801:Humans; D007031:Hypothalamus / Q000032:analysis* / Q000196:embryology; D010455:Peptides / Q000032:analysis; D013116:Spinal Cord / Q000032:analysis* / Q000196:embryology; D013373:Substance P / Q000032:analysis*
D010455:Peptides; D013373:Substance P