Plasma pattern of immunoreactive ACTH in normal man and in patients with Nelson's syndrome

1981 ◽  
Vol 96 (1) ◽  
pp. 15-23 ◽  
Author(s):  
M. Thorén ◽  
M. Ajne ◽  
K. Hall

Abstract. A radioimmunoassay for ACTH determinations in human plasma was developed using an N-terminal antiserum. Plasma ACTH levels at 6 a.m. in 39 patients with normal pituitary-adrenal function were below 4 pmol/l in two individuals. The remaining had a mean of 32.7 ± 4 pmol/l (n = 37). Gel filtration on Sephadex G-50 medium and G-75 revealed that a high molecular weight immunoreactive ACTH was found in plasma from both normal individuals and patients with Nelson's syndrome. The stimulation of ACTH secretion with metyrapone (750 mg perorally) significantly increased the mean plasma levels of 1–39 ACTH after 3 h (from 0.9 to 6.6 pmol/l) in 10 healthy individuals. The level of the high molecular weight form remained constant. In one patient with Nelson's syndrome hydrocortisone iv (100 mg/h for 3 h) suppressed the total ACTH levels from 360 to 83 pmol/l following corticoid withdrawal on the previous evening, but did not affect the high molecular weight form of ACTH. The difference between the amounts of immunoreactive ACTH found in plasma from normal individuals and from patients with Nelson's syndrome was attributed to 1–39 ACTH.

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 713-722
Author(s):  
W.M. Kuhtreiber ◽  
F. Serras ◽  
J.A.M. van den Biggelaar

We have injected horseradish peroxidase (HRP) and fluorescein-isothiocyanate dextran (FD) into cells and into the blastocoelic cavity of Patella vulgata embryos, before and during the interval between 5th and 6th cleavage, in which the mesodermal stem cell is determined by means of interactions between the central 3D macromere and the contacting animal micromeres. Intracellular injections of HRP at different stages showed that, whereas before this contact phase no spreading of label was observed, a clear intercellular transfer of HRP was found after the contact was established. Control experiments showed that it was HRP in its intact, high molecular weight form that was transferred in the living embryo. Injections of HRP into the blastocoelic cavity gave essentially the same results. In these cases, the HRP was taken up by the cells from contact stage onwards. When FD was injected into the blastocoelic cavity, no uptake was observed, not even after prolonged presence of FD in it. However, when HRP and FD were mixed, both were taken up, starting at contact stage. Differences in labelling pattern of HRP, as compared with FD, and a shift of the FD fluorescence after uptake, suggest that receptor-mediated endocytosis is involved. The possible morphogenetic significance of the transfer mechanism is discussed.


1977 ◽  
Author(s):  
K. A. Rickard ◽  
T. Exner ◽  
H. Kronenberg

Gel filtration of human plasma cryoprecipitate on Sepharose 2B indicated the molecular weight of factor VIII coagulant activity (VIIIc) to be significantly greater than that found in antihaemophilic concentrate. Polyethylene glycol at 3% concentration precipitated approximately half of the VIIIc from cryoprecipitate. This activity eluted as high molecular weight material on gel filtration. The addition of more polyethylene glycol to a concentration of 8% precipitated most of the remaining VIIIc from cryoprecipitate. This activity appeared to be of significantly lower molecular weight, approximately corresponding in elution volume to that observed for antihaemophilic concentrate. The possibility that an antibody to VIIIc generated in a patient treated with cryoprecipitate might be directed against the higher molecular weight form of factor VIII was investigated. However, no significant differences between the higher and lower molecular weight forms of factor VIII either in stability or in reactivity with human antibody to factor VIII were found.


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