scholarly journals The isolation of purified neurosecretory granules from bovine pituitary posterior lobes. Comparison of granule protein constituents with those of neurophysin

1967 ◽  
Vol 104 (3) ◽  
pp. 1082-1088 ◽  
Author(s):  
CR Dean ◽  
DB Hope
1968 ◽  
Vol 106 (2) ◽  
pp. 565-573 ◽  
Author(s):  
C. R. Dean ◽  
D B Hope

1. An improved procedure for the isolation of neurosecretory granules from the posterior lobe of the bovine pituitary gland is described. 2. Of the total oxytocic and pressor activities present in the original tissue 80% was sedimentable. 3. The granules were separated from mitochondria by prolonged centrifugation in a sucrose density gradient. During a sedimentation period of 5hr. the granules moved progressively into denser regions of the gradient and the mitochondria remained at the top. 4. The biological activities of the granules were measured: the oxytocic activity was 11·56±1·63 and the pressor activity was 15·60±3·91 units/mg. of protein. 5. A protein was isolated from a lysate of granules prepared from 40 pituitary glands. Amino acid analysis showed that it consisted of a mixture of neurophysin-I and neurophysin-II in equal proportions. It accounted for 60% of the soluble granule protein and for 50% of the total granule protein. 6. The neurophysins present in the granules are associated with 19·1 units of oxytocic and 21·1 units of pressor activity/mg. of protein. 7. Starch-gel electrophoresis revealed the presence of both neurophysins in extracts of 15 pituitary glands studied individually. 8. We conclude that the polypeptide hormones, oxytocin and [8-arginine]-vasopressin, are normally closely associated with the two neurophysins within neurosecretory granules of the pituitary gland.


Author(s):  
Richard R. Shivers

The sinus gland is a neurohemal organ located in the crayfish eyestalk and represents a storage site for neurohormones prior to their release into the circulation. The sinus gland contains 3 classes of dense, membrane-limited granules: 1) granules measuring less than 1000 Å in diameter, 2) granules measuring 1100-1400 Å in diameter, and 3) granules measuring 1500-2000 Å in diameter. Class 3 granules are the most electron-dense of the granules found in the sinus gland, while class 2 granules are the most abundant. Generally, all granules appear to undergo similar changes during release.Release of neurosecretory granules may be initiated by a preliminary fragmentation of the “parent granule” into smaller, less dense vesicles which measure about 350 Å in diameter (V, Figs. 1-3). A decrease in density of the granules prior to their fragmentation has been observed and may reflect a change in the chemical nature of the granule contents.


2021 ◽  
Author(s):  
Yanhong Zhang ◽  
Changli Yue ◽  
Anna M. Krichevsky ◽  
Igor Garkavtsev

1976 ◽  
Vol 68 (2) ◽  
pp. 225-NP ◽  
Author(s):  
J. F. MORRIS

SUMMARY The distribution of neurosecretory granules in various anatomical compartments of neurosecretory axons of the neural lobe of the rat pituitary has been studied. Apart from the most anterior tip of the gland, where granules are largely restricted to undilated axons and a few 'swellings', the proportional compartmental storage of granules is essentially homogeneous for the rest of the gland: 13% of granules are found in undilated axons, 31% in axonal 'endings' (which contain microvesicles and abut the basement membrane) and 55% in axonal 'swellings' (which are devoid of significant numbers of microvesicles). These values indicate that the 'endings' contain a much greater proportion of the total number of granules stored in the neural lobe than would be predicted if the readily releasable pool of hormone were composed of all the granules in the 'endings'. Some further constraint on granule release either physiological or anatomical (e.g. the position of the granule in relation to the plasmalemma of the 'ending') must be operative.


2014 ◽  
Vol 5 ◽  
Author(s):  
Avinash Sheshachalam ◽  
Nutan Srivastava ◽  
Troy Mitchell ◽  
Paige Lacy ◽  
Gary Eitzen

2001 ◽  
Vol 125 (3) ◽  
pp. 397-399
Author(s):  
Andrea G. Kahn ◽  
Alejandra Avagnina ◽  
Jorge Nazar ◽  
Boris Elsner

Abstract Primitive neuroectodermal tumors occur most frequently in bone and soft tissue but have been reported in other locations. Primary lung primitive neuroectodermal tumors without pleural or chest wall involvement are extremely rare. We present a case with immunohistochemical and ultrastructural studies and follow-up of the patient. An 18-year-old man presented with hemoptysis. Chest radiographs revealed a right middle lobe mass, and bronchoscopy showed an endobronchial tumor. The lesion was resected by middle lobectomy. After 2 years, a local recurrence was treated by pneumonectomy. The patient died after surgery. Histologically, the tumor was composed of uniform cells with round nuclei and scanty cytoplasm arranged in cohesive lobules with occasional rosette formation. Immunohistochemically, the tumor was positive for vimentin, CD99, neuron-specific enolase, and neurofilaments. Ultrastructural study revealed neurosecretory granules and cytoplasmic processes. Our case shows the value of immunohistochemistry and electron microscopy in the diagnosis of primitive neuroectodermal tumors in unusual locations.


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