Characterization of Plasma Beta-Endorphin - Like Immunoreactivity in Primates and Humans.

Beta-endorphin ((beta)-END) is a potent opiate-like peptide which has been implicated in analgesic phenomena which may be useful in the development of innovative nursing interventions. In this dissertation methods to measure all forms of (beta)-END-like peptides in human plasma were reported. The methods were further validated by the characterization of (beta)-END-like immunoreactivity in the rhesus monkey (Macaca mulatta). The relationship between changes in plasma (beta)-END-like immunoreactivity and self-reported pain perception and anxiety was explored by studying women during pregnancy and labor. Plasma (beta)-END-like immunoreactivity increased steadily and significantly (Tau B = 0.4, N = 23, p = 0.008) throughout pregnancy. There was a slight but nonsignificant increase during labor which was not correlated with changes in self-reported pain perception or anxiety. Within twenty-four hours postpartum, plasma (beta)-END-like immunoreactivity had returned to control levels. Characterization of the (beta)-END-like immunoreactivity in plasma from pregnant women at term by molecular sieving chromatography indicated that the majority of the material was (beta)-END-sized which is in contrast to that observed in the nonpregnant control plasma in which the major species was (beta)-lipotropin-sized. The (beta)-END-like material contained in human placenta, was also primarily (beta)-END-sized with a portion of it being the non opiate N-acetylated form. Plasma (beta)-END-like immunoreactivity during pregnancy is not associated with altered pain perception or anxiety, but rather, may be more reflective of major endocrine alterations associated with pregnancy.PhDNursingUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/159712/1/8402252.pd