Maturation of hypothalamic neurosecretion in rat, with special reference to the neurosecretory material passing into the hypophysial portal system

1965 ◽  
Vol 27 (2) ◽  
pp. 166-183 ◽  
Author(s):  
U. K. Rinne ◽  
E. Kivalo
1960 ◽  
Vol XXXIV (I) ◽  
pp. 8-18 ◽  
Author(s):  
E. Kivalo ◽  
U. K. Rinne

ABSTRACT Acute stress, chronic stress plus hydration, cortisone treatment, cortisone treatment plus dehydration were used as methods of investigation and the relation between the neurosecretory activity of the hypothalamic supraoptic nucleus and paraventricular nucleus and the neurosecretory material around the hypophysial portal vessels of the median eminence on the one hand and the corticotrophin release on the other hand, has been studied in the rat. Whereas stress stimulates both the activity of the above mentioned cells of the hypothalamus and the ACTH release, stress plus hydration causes a depression of these hypothalamic cells but nevertheless causes a marked ACTH release. Cortisone inhibits the activity of the cells in the supraoptic nucleus and the paraventricular nucleus as well as the ACTH release whereas cortisone plus dehydration causes stimulation but inhibits the ACTH release. In some stress and cortisone treatment groups the variations of the neurosecretory material around the hypophysial portal vessels and of the ACTH release were found to show a correlation. It is concluded that the activity of the cells of the supraoptic nucleus and the paraventricular nucleus and the ACTH release do not seem to have any definite connection, whereas some observations indicate that the neurosecretory material in the region of the median eminence around the hypophysial portal vessels may have some significance in ACTH release.


1959 ◽  
Vol 18 (1) ◽  
pp. 118-NP ◽  
Author(s):  
A. HOWE ◽  
P. A. JEWELL

SUMMARY The effects of dehydration, brought about by water deprivation over a period of 10 days, upon the stainable neurosecretory material (NSM) of the hypothalamo-hypophysial system were compared in two species of rodents originating from different climatic habitats, namely the laboratory rat (Rattus norvegicus) and the desert rat (Meriones meriones). While the neural lobe of the laboratory rat was virtually completely depleted of NSM by this procedure, that of the desert rat showed no detectable histological changes. No striking changes were found in the hypothalamus of either species following this period of water deprivation, although there was some indication of disappearance of NSM from the hypothalamus in the desert rat. The results are briefly discussed in relation to the theory of hypothalamic neurosecretion.


1959 ◽  
Vol s3-100 (51) ◽  
pp. 463-482
Author(s):  
M. ALLANSON ◽  
C. L. FOSTER ◽  
G. MENZIES

Evidence is presented which suggests that in this animal the pars tuberalis may have some function in addition to acting as a bed for the hypophysial portal system, since its cells appear rich in RNA. The granules of the cells of the pars intermedia are shown to be PAS-positive, but this reaction, unlike that of the basiphil cells of the pars distalis proper and the zona tuberalis, is readily prevented by pretreatment of sections with proteolytic enzymes. A study of the basiphil cells of the pars distalis proper and of the zona tuberalis, based on cytological characteristics, size, and shape, provides some evidence for the existence of two, and possibly three, kinds of basiphil cell. The lipid inclusions of the adenohypophysial cells and their relationship to the Golgi elements are described, together with some brief preliminary observations upon the electron microscopic characteristics of acidophil and basiphil cells.


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