Endocrine cells

Voltage-gated Ca2+ channels are Ca2+-selective pores in the plasma membrane of electrically excitable cells, such as neurons, muscle cells, (neuro) endocrine cells, and sensory cells. They open in response to membrane depolarization (e.g., an action potential) and permit the influx of Ca2+ along its electrochemical gradient into the cytoplasm. 

The hormone peptide YY (PYY) is a 36 amino acid peptide, which is closely related to neuropeptide Y and pancreatic polypeptide. PYY is predominantly synthesised and released by intestinal endocrine cells, and can also coexist with glucagon in pancreatic acini and enteroglucagon in endocrine cells of the lower bowel. It acts on the same receptors as neuropeptide Y. The endogenous long C-terminal PYY fragment PYY3 36 is a biologically active and subtype-selective metabolite. 

The vesicular monoamine transporters (VMATs) were identified in a screen for genes that confer resistance to the parkinsonian neurotoxin MPP+ [2]. The resistance apparently results from sequestration of the toxin inside vesicles, away from its primary site of action in mitochondria. In addition to recognizing MPP+, the transporter s mediate the uptake of dopamine, ser otonin, epinephrine, and norepinephrine by neurons and endocrine cells. Structurally, the VMATs show no relationship to plasma membrane monoamine transporters. 

Delta receptors are relatively selective for two related penta-peptides, methionine enkephalin and leucine enkephalin (met- and leu-enkephalin), which were isolated from porcine brain (Hughes 1975). Both met- and leu-enkephalin inhibit electrically induced contractions of guinea pig ileum, an effect that mimics those effects seen with opioid drugs, and is naloxone reversible. The enkephalins are processed posttranslational ly from proenkephalin, and secreted from central and peripheral neurons and endocrine cells in the adrenal medulla. 

Secretin Endocrine cells in mucosa of duodenum Acid in duodenum Inhibits gastric emptying and gastric secretion stimulates secretion of bicarbonate from pancreas stimulates secretion of bicarbonate-rich bile from liver... 

Gastric inhibitory Endocrine cells in mucosa Lipids, acid, and Inhibits gastric emptying and gastric... 

It has been known for some time that the enteric nervous system does not simply regulate smooth muscle contraction, but is intimately involved in the control of transport processes in enterocytes. Nerve fibres in the mucosa terminate subjacent to the basement membrane of epithelial and entero-endocrine cells, on which muscarinic acetylcholine receptors (mAChRs)... 

Cav1.2 Otic Cardiac and smooth muscle, endocrine cells, CNS, neuron cell bodies... 

Pow, D.V., and Morris, J.F. (1991) Membrane routing during exocytosis and endocytosis in neuroendocrine neurons and endocrine cells Use of colloidal gold particles and immunocytochemical discrimination of membrane compartments. Cell Tissue Res. 264, 299-316. 

Behr JP, Demeneix B, Loeffler JP, Perez-Mutul J. Efficient gene transfer into mammalian primary endocrine cells with lipopolyamine-coated DNA. Proc Natl Acad Sci USA 1989 86(18) 6982-6986. 

Figure 4.2 Substructure of the wall in the gastrointestinal tract. (Not to scale). Epithelial cells of the villi possess micro villi which extend into the lumen (Not shown). The epithelium consists of absorptive enterocytes, endocrine cells that secrete peptide and goblet cells that secrete mucus.

This process is important for proliferating cells, in which cholesterol is reqnired for formation of new membranes, and for some endocrine cells (in the testis, ovary and adrenal cortex) for the synthesis of steroid hormones. 

Membrane-located enzymes in the sER catalyze lipid synthesis. Phospholipid synthesis (see p. 170) is located in the sER, for example, and several steps in cholesterol biosynthesis (see p. 172) also take place there. In endocrine cells that form steroid hormones, a large proportion of the reaction steps involved also take place in the sER (see p. 376). 

Ellis LC, Berliner DL. 1967. The effects of ionizing radiations on endocrine cells. Radiation Res 32 520-537. 

In endocrine signaling the hormone is synthesized in specific signaling, or endocrine, cells and exported via exocytosis into the extracellular medium (e.g. blood or lymphatic fluid in animals). The hormone is then distributed throughout the entire body via the circulatory system so that remote regions of an organism can be reached. 

IDDM is a disease in which /3 cells of islets are selectively destroyed. How does a nonspecific effector molecule (nitric oxide) mediate the selective destruction of the /3 cell We propose that the specificity of cytokine interactions with the /8 cell, and the intrinsic sensitivity of the /3 cell to oxidative damage relative to other endocrine cells may impart this selective destruction. In rats the effects of lL-1 appear to be specific to the /3 cell. lL-1 induces iNOS expression and the overproduction of nitric oxide by /3 cells, but does not induce expression of iNOS or nitric oxide formation in other islet endocrine or nonendocrine cells of the... 

L Cayl. 1-Cavl 3 Cardiac, skeletal, smooth muscle, neurons (Cav1.4 is found in retina), endocrine cells, bone Long, large, high threshold Verapamil, DHPs, Cd2+, [Pg.259]

In close proximity to the parietal cells are gut endocrine cells called enterochromaffin-like (ECL) cells. ECL cells also have receptors for gastrin and acetylcholine, which stimulate histamine release. Histamine binds to the H2 receptor on the parietal cell, resulting in activation of adenylyl cyclase, which increases intracellular cyclic adenosine... 

---