Immunochemical Studies on the Storage and Axonal Transport of Neurophysins in the Hypothalamo‐neurohypophyseal System

Livett, Bruce G.

doi:10.1111/j.1749-6632.1975.tb34180.x

Cited by 12 publications

(1 citation statement)

References 66 publications

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“…It is reasonable to assume that neurosecretions into the CSF may affect the activity of other supraependymal neurons (receptor-type) and tanycytes lining the ventricle (Bruni et al, 1977;Ribas, 1977;Scott et al, 1977). In this regard, tanycytes have demonstrated a capacity to take up neurochemical substances from the CSF, transport them to their basal process, and release them into the perivascular space of HPS (Knigge and Scott, 1970;Kobayashi et al, 1972;Joseph et al, 1973;Scott et al, 1974;Livett, 1975;Paull et al, 1977Paull et al, , 1978. In the present study, tanycytes of estradiol-treated animals possess greater numbers of microvilli over their luminal surfaces than do the normally cycling and ovariectomized groups.…”

Section: Fig 4 Supraependymal Cells and Their Processes Numerous Smentioning

confidence: 99%

The median eminence in normal, ovariectomized, and ovariectomized‐estradiol‐treated hamsters: An ultrastructural study

Merchant

Dollar

1981

Am. J. Anat.

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In an effort to define more clearly the effect various plasma concentrations of estrogen have on the morphology and function of tanycytes, the present investigation examined the median eminence (ME) of normally cycling, ovariectomized, and ovariectomized-estradiol-treated hamsters. In normally-cycling animals, when endogenous estrogen was at its highest level (day 4 or proestrus), numerous microappendages arose from the luminal surfaces of tanycytes located in the ventrolateral region of the ME. Large blebs (1.0-5.0-micrometers diameter), miniblebs (1.0-micrometer diameter), and microvilli dominated the surfaces of these cells. Large blebs appeared to have been formed by the coalescence of several miniblebs and were composed of cytoplasmic ground substance devoid of organelles. The peduncular shape of many of these blebs suggested their involvement in an apocrinelike secretion by the tanycyte. When endogenous estrogen levels were low (day 1 of the estrous cycle), the tanycytes of normally cycling hamsters possessed slightly fewer microappendages. Following ovariectomy, large blebs were nearly absent from the luminal surfaces of tanycytes, and the number of miniblebs and microvilli were also greatly reduced. Subcutaneous injections of 17-beta estradiol benzoate restored the large blebs to the tanycyte surface. The number and variety of tanycytic microappendages in these animals resembled those in normally cycling hamsters on day 4 of the estrous cycle. The present study demonstrates that tanycytes of the hamster ME are sensitive to estrogen and vary in their morphology in relation to the animal's reproductive status. These changes in tanycyte morphology can be correlated directly to functions of absorption (microvilli) and secretion (blebs). The sensitivity of tanycytes to estrogen suggests that these cells may also play a role in the hypophyseal-ovarian feedback mechanism.

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Section: Fig 4 Supraependymal Cells and Their Processes Numerous Smentioning

confidence: 99%

The median eminence in normal, ovariectomized, and ovariectomized‐estradiol‐treated hamsters: An ultrastructural study

Merchant

Dollar

1981

Am. J. Anat.

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Neurophysine – molekulare und zelluläre Aspekte

Acher

1979

Angewandte Chemie

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Neurophysine sind lineare, cysteinreiche Proteine aus 93-95 Aminosaureresten, die wie die Neurohypophysenhormone Oxytocin und Vasopressin im Hypothalamus entstehen und von dort zum Hypophysen-Hinterlappen gelangen. Meistens enthalt eine Spezies zwei (oder drei) Neurophysine, die sich nur geringfugig in Kettenlange und/oder Sequenz unterscheiden. Viele Beobachtungen sprechen dafiir, daR sowohl Oxytocin und eines der Neurophysine als auch Vasopressin und das andere Neurophysin einen gemeinsamen Vorlaufer haben, dessen lange Kette in Neurophysin und Hormon gespalten wird. An Ratten mit erblichem Diabetes insipidus lieR sich zeigen, daR ein einziges Gen die Biosynthese des Vasopressins und eines der Neurophysine kontrolliert. Angew. Chem. 91, 905-919 (1979) 0 Verlag Chemie. CnibH, D-6940 Weinheim, 1979 0044-8249f 79/1111-0905 $02.50/0 Abb. 4. Papierelektrophoretische Identifizierung von Oxytocin und Arginin-Vasopressin im kathodischen Material, das durch Elektrodialyse des Uherstands nach Spaltung des ,,aktiven" Komplexes rnit 0.5proz. Trichloressigsaure erhalten wird. Oben: Elektrophoresestreifen, mit Bromphenolblau entwickelt. darunter Nummern der Fraktionen. Unten: Aktivitatstest; .... Oxytocin-Aktivitat, ----Vasopressin-Aktivitat. I= Wanderungsstrecke in Richtung Kathode (nach [20]). Angew. Chem. 91. 90s-919 (1979)

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Neurophysins: Molecular and Cellular Aspects

Acher

1979

Angew. Chem. Int. Ed. Engl.

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Neurophysins are linear cystine‐rich proteins containing 93–95 amino acid residues which like the neurohypophysial hormones oxytocin and vasopressin are formed in the hypothalamus and travel from there to the hypophysial posterior lobe. A species usually contains two (or three) neurophysins which differ only slightly in chain length and/or sequence. Many observatios suggest that both oxytocin and one of the neurophysins as well as vasopressin and the other neurophysin have a common precursor whose long chain is split into neurophysin and hormone. It can be shown on rats having considerable diabetes insipidus that a single gene controls the biosynthesis of the vasopressin and one of the neurophysins.

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Immunochemical Studies on the Storage and Axonal Transport of Neurophysins in the Hypothalamo‐neurohypophyseal System

Cited by 12 publications

References 66 publications

The median eminence in normal, ovariectomized, and ovariectomized‐estradiol‐treated hamsters: An ultrastructural study

The median eminence in normal, ovariectomized, and ovariectomized‐estradiol‐treated hamsters: An ultrastructural study

Neurophysine – molekulare und zelluläre Aspekte

Neurophysins: Molecular and Cellular Aspects

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