Endogenous Opioid Peptides Suppress Cytokine-Mediated Upregulation of HIV-1 Expression in the Chronically Infected Promonocyte Clone U1

1995 ◽  
pp. 65-72 ◽  
Author(s):  
Chun C. Chao ◽  
Genya Gekker ◽  
Wen S. Sheng ◽  
Shuxian Hu ◽  
Philip S. Portoghese ◽  
...  
Keyword(s):  
Opioid Peptides ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid ◽  
Hiv 1

scholarly journals Identification of a novel Na+- and Cl−-coupled transport system for endogenous opioid peptides in retinal pigment epithelium and induction of the transport system by HIV-1 Tat

2003 ◽  
Vol 375 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Huankai HU ◽  
Seiji MIYAUCHI ◽  
Christy C. BRIDGES ◽  
Sylvia B. SMITH ◽  
Vadivel GANAPATHY
Keyword(s):  
Transport System ◽  
Opioid Peptides ◽  
Mammalian Cells ◽  
Retinal Pigment ◽  
Coupled Transport ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid ◽  
Rpe Cells ◽  
High Affinity ◽  
Hiv 1

The endogenous opioid peptides enkephalins, dynorphins and endorphins consist of five or more amino acids. These peptides participate in a multitude of biological functions in mammalian cells by interacting with different subtypes of opiate receptors located on the plasma membrane and in the nucleus. Here we report on the identification of a new peptide transport system in the human retinal pigment epithelial (RPE) cells that transports a variety of endogenous opioid peptides with high affinity. We identified this novel, hitherto unrecognized, transport system when we were analysing the differential effects of Tat, the transacting factor encoded by HIV-1, on various transport processes in RPE cells. This transport system is markedly induced by Tat. This opioid transport system is energized by transmembrane Na+ and Cl− gradients and is distinct from any of the previously identified transport systems for opioid peptides in mammalian cells. Free amino acids, dipeptides, tripeptides and non-peptide opiate receptor antagonists are excluded by this newly identified transport system. The affinities of endogenous opioid peptides for this system are in the range of 0.4–40 μM. The identification of the high-affinity Na+- and Cl−-coupled transport system in mammalian cells that is specific for endogenous opioid peptides and is induced by HIV-1 Tat is of significance not only to the biology of opioid peptides but also to the pathology of HIV-1 infection in humans.

Do Endogenous Opioid Peptides Cause Hepatic Encephalopathy?

1987 ◽  
Vol 72 (s16) ◽  
pp. 90P-91P
Author(s):  
J.R. Thornton ◽  
M.S. Losowsky
Keyword(s):  
Hepatic Encephalopathy ◽  
Opioid Peptides ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid

Met5-enkephalin protects isolated adult rabbit cardiomyocytes via δ-opioid receptors

1999 ◽  
Vol 277 (6) ◽  
pp. H2442-H2450 ◽  
Author(s):  
Yasushi Takasaki ◽  
Roger A. Wolff ◽  
Grace L. Chien ◽  
Donna M. van Winkle
Keyword(s):  
Cell Death ◽  
Opioid Receptors ◽  
Ischemic Preconditioning ◽  
Opioid Peptides ◽  
Trypan Blue ◽  
Adult Rabbit ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid ◽  
Simulated Ischemia ◽  
Hypoxic Incubation

In rats and rabbits, endogenous opioid peptides participate in ischemic preconditioning. However, it is not known which endogenous opioid(s) can trigger cardioprotection. We examined preconditioning-induced and opioid-induced limitation of cell death in isolated, calcium-tolerant, adult rabbit cardiomyocytes. Cells were subjected to simulated ischemia by pelleting and normothermic hypoxic incubation. Preconditioning was elicited with 15 min of simulated ischemia followed by 15 min of resuspension and reoxygenation. All cells underwent 180 min of simulated ischemia. Cell death was assessed by trypan blue permeability. Morphine protected cells, as did preconditioning; naloxone blocked the preconditioning-induced protection. Exogenous Met5-enkephalin (ME) induced protection, but exogenous β-endorphin did not. ME-induced protection was blocked by the δ-selective antagonist naltrindole. Additionally, two other proenkephalin products, Leu5-enkephalin and Met5-enkephalin-Arg-Phe, provided protection equipotent to ME. These data suggest that one or more proenkephalin products interact with δ-opioid receptors to endogenously trigger opioid-mediated protection.

Involvement of endogenous opioid peptides in the antinociception induced by the novel dermorphin tetrapeptide analog amidino-TAPA

2007 ◽  
Vol 560 (2-3) ◽  
pp. 150-159 ◽  
Author(s):  
Hirokazu Mizoguchi ◽  
Chizuko Watanabe ◽  
Hiroyuki Watanabe ◽  
Kaori Moriyama ◽  
Bunsei Sato ◽  
...  
Keyword(s):  
Opioid Peptides ◽  
The Novel ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid
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