Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tannic acid methods have been applied to capture the exocytosis of peptide-containing granules from peptidergic neurons. The captured exocytoses have been quantitated to assess the proportion and amount of peptide released at different parts of the neuronal membrane. Examination of hypothalamic synaptic boutons shows that only about one-half of the peptidergic vesicles is exocytosed into the synaptic cleft and also that exocytosis also occurs from undilated peptidergic axons. Study of the magnocellular neurosecretory system reveals that all parts of their extensive terminal arborization appear to be equally capable to exocytose peptide. Only about one-half of their peptide is released from their nerve endings, which about the capillaries. The remainder is released much deeper in the lobules of secretory tissue where its principal target(s) could be the pituicytes and/or neurosecretory axons. Dendrites of magnocellular neurons are also capable of releasing peptide by exocytosis and dendrites could release sufficient oxytocin and vasopressin to account for the peptide known to be released into the hypothalamus. We conclude that peptidergic neurons release substantial amounts of peptides from all of their processes and that this must be taken into account when considering what functions those peptides might serve.
Anat Rec 1991 Dec
PMID:Widespread release of peptides in the central nervous system: quantitation of tannic acid-captured exocytoses. 179 74

Tannic acid was used to demonstrate continuity of intracellular channels with extracellular space in white adipose tissue of adult rats, brown adipose tissue of suckling rats, and liver of diabetic rats. Electron-opaque material resulting from treatment of glutaraldehyde-fixed tissue with tannic acid was found in extracellular space, invaginations of cell surfaces, vesicles, and intracellular channels. Electron-opaque material was present in channels that surrounded lipid droplets in both white and brown adipocytes and in hepatocytes. The small distance between the lumen of marked channels and lipid droplets in adipocytes indicates that a monolayered structure, perhaps a leaflet of membrane lining the channel. Similar findings were obtained in brown adipose tissue using lanthanum instead of tannic acid to mark intracellular channels continuous with extracellular space. Since endoplasmic reticulum is the primary site of triacylglycerol synthesis in adipocytes, marked channels near lipid droplets may be elements of endoplasmic reticulum. Some of the channels marked with tannic acid in hepatocytes contained lipoprotein particles, whereas others were located, in relation to mitochondria and lipid droplets, in the same sites as endoplasmic reticulum in untreated tissue. This indicates that some of the channels marked with tannic acid in hepatocytes are endoplasmic reticulum. Presence of electron-opaque material in intracellular channels and vesicles, but not in cytoplasm, of treated tissue indicates the channels and vesicles were open to extracellular space during treatment with tannic acid or lanthanum and, furthermore, that their membranes were continuous with plasma membrane.
Anat Rec 1982 Jun
PMID:Continuity of intracellular channels with extracellular space in adipose tissue and liver: demonstrated with tannic acid and lanthanum. 628 84