Corticoliberin-immunoreactive cell bodies localised in two distinct areas of the sheep hypothalamus.
The localisation of corticoliberin producing neurones in the sheep hypothalamus was attempted with an antiserum directed against synthetic ovine CRF by the indirect immunofluorescence procedure. Synthetic ovine corticoliberin-immunoreactive fibres were detected, in order of decreasing importance, in the external median eminence, in the caudal neural lobe around capillaries, at the boundary of the neural and intermediate lobe, around the anterior commissure, in the paraventricular nuclei and in the posterior hypothalamus and midbrain, suggesting that synthetic ovine corticoliberin-related substances act not only on anterior pituitary tissue, but also on the intermediate lobe, on central neurones and on peripheral target organs. Two groups of cell bodies reacted to the anti-synthetic ovine corticoliberin antiserum. The first group was located in the paraventricular nuclei and consisted of 15-20 microns diameter cell bodies with a granular cytoplasm. The second group was located mainly in the dorsolateral caudal hypothalamus, and the cell bodies were smaller (10-15 microns) and had a smooth cytoplasm. No cell bodies were detected in the basal hypothalamus). Synthetic ovine corticoliberin-immunoreactive structures did not contain immunoreactive neurophysin. The synthetic ovine corticoliberin-immunoreaction in the paraventricular neurones was abolished by preincubating the antiserum with synthetic ovine corticoliberin but not with sauvagine or several other peptides. The immunoreaction in the posterior hypothalamic groups was abolished by preincubating the synthetic ovine corticoliberin antiserum with both synthetic ovine corticoliberin and sauvagine, but not with other peptides. The results suggest that the immunoreaction was specific for synthetic ovine corticoliberin in the paraventricular but not posterior hypothalamic region. The relative contribution of both areas to synthetic ovine corticoliberin-like peptides containing nerve terminals of the median eminence remains to be established.
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007031:Hypothalamus / Q000378:metabolism*; D007034:Hypothalamus, Posterior / Q000378:metabolism; D008326:Mammillary Bodies / Q000378:metabolism; D008473:Median Eminence / Q000378:metabolism; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009481:Neurophysins / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism; D010904:Pituitary Gland, Posterior / Q000378:metabolism; D012756:Sheep
D009481:Neurophysins; D003346:Corticotropin-Releasing Hormone