CATECHOLAMINES IN TISSUES OF THE HUMAN FETUS

[摘要] Various tissues of the early human fetus were studied, in terms of their catecholamine content, as a means of evaluating the level of maturation of the sympathetic nervous system and chromaffin tissue.Epinephrine was found in significant amounts in the adrenal medulla but not in para-aortic chromaffin tissue. Its presence in the medulla was recorded by fluorescent analysis, bioassay and quantitative paper chromatography. Although the reasons for the differences between these findings and those reported previously by others remains unclarified, the following conclusions may be made: 1) the total catecholamine content of fetal adrenal glands is extremely low, reflecting the scanty occurrence of adrenal chromaffin tissue, 2) norepinephrine is the predominant amine in chromaffin tissue in fetal life, present in greater absolute and relative amounts in extramedullary rather than medullary chromaffin tissue, 3) epinephrine is present in the adrenal gland from a very early stage of fetal life, and 4) the physiologic importance of either epinephrine or norepinephrine in the chromaffin tissue of the fetus awaits elucidation.In organs, the content of catecholamines roughly parallels that of adult members of other species, indicating the presence of a potentially functioning adrenergic nerve supply at an early stage of development.In cerebral tissue, the content of catecholamines appears to be much lower than adult tissue in the early fetus. Dopamine is not present in brains of fetuses, at least during the first trimester of pregnancy, suggesting a dissociation of function between dopamine and norepinephrine in the central nervous system.

[学科分类] 儿科学