ISSN:
1432-0878
Keywords:
Rat hypothalamic magnocellular system
;
Immunochemistry
;
ACTH-β-Endorphin
;
Pro-opiocortin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Antisera raised against ACTH (1–39), β-endorphin and the 16K proopiocortin were used, in association with the immunoperoxidase reaction, to localize positively-staining cell bodies and nerve fibres in the hypothalamus of the rat. Antigens, cross-reactive against anti-ACTH (1–39) serum were detected in a fibre system in the rostro-dorsal hypothalamus situated between the optic chiasm and the third ventricle while immunoreactive 16K-like material was present in fibres localized in the caudal hypothalamus, dorso-lateral to the arcuate nucleus. This latter system was also associated with the appearance of ACTH (1–39) and ACTH (17–39) immunoreactivity. Cells of the arcuate nucleus stained positively for ACTH (1–39), 16K antigen and β-endorphin, and on examining adjacent thin sections it was observed that cells that contained 16K antigen-like material, also gave a positive immunoreaction with ACTH (1–39) and β-endorphin antisera. In the magnocellular system, cells of the supraoptic (SON) and paraventricular (PVN) nuclei also gave a positive immunoreaction with anti-ACTH (1–39), 16K antigen and β-endorphin serum. As in the case of the arcuate nucleus, common cells stained for these three antigens. On the basis of the precursor theory for the synthesis of ACTH, 16K antigen and β-endorphin, it was not unexpected to find these three fragments of pro-opiocortin localized together in cells of the arcuate nucleus. That ACTH (1–39), 16K antigen and β-endorphin-like materials are present in the magnocellular neurosecretory system would suggest that cells of the SON and PVN are not only involved in the synthesis of neurophysin and the neurohypophysial hormones, but also of some products of the pro-opiocortin molecule. Whether the biochemical nature of the ACTH and β-endorphin in cells of the SON and PVN is identical to that of anterior pituitary origin remains to be established, as does the biosynthetic relationship between neurophysin and oxytocin/ vasopressin and these fragments of pro-opiocortin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00239330
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