Interaction of a bovine thymic peptide extract with vasoactive intestinal peptide (VIP) receptors

1986 ◽  
Vol 6 (6) ◽  
pp. 579-584
Author(s):  
J. M. Guerrero ◽  
R. Goberna ◽  
P. Molinero ◽  
J. Jimenez ◽  
J. R. Calvo
Keyword(s):  
Adenylate Cyclase ◽  
Plasma Membranes ◽  
Mononuclear Cells ◽  
Weight Basis ◽  
Lymphoid Cells ◽  
Vip Receptors ◽  
Liver Plasma Membranes ◽  
Blood Mononuclear Cells ◽  
Rat Liver Plasma Membranes ◽  
Thymic Peptide

Bovine t hymic peptide extract (1–100 μg/ml) is shown to completely inhibit the binding of [125I]VIP to rat blood mononuclear cells, lymphoid cells of spleen, and liver plasma membranes. In the three models, the bovine thymic peptide extract inhibits [125I]VIP binding with a potency that is 4000–7000 times lower than that of the native VIP, on a weight basis. In rat liver plasma membranes, the bovine thymic peptide extract stimulates adenylate cyclase with a maximal efficiency that is similar to that of VIP. At maximal doses, VIP and thymic peptide extract do not exert an additive effect on adenylate cyclase, suggesting that the activation of the enzyme by the bovine thymic peptide extract occurs through VIP receptors. Finally, no VIP-like immunoreactivity was detected in the thymic peptide extract using an antiserum raised against mammalian VIP. All these data suggest the presence in the bovine thymic peptide extract of a new substance which behaves as a VIP agonist in rat.

Interaction of thymic peptide thymosin α1 with vasoactive intestinal peptide (VIP) receptors

1986 ◽  
Vol 6 (8) ◽  
pp. 727-733 ◽  
Author(s):  
J. R. Calvo ◽  
R. Goberna ◽  
J. M. Guerrero
Keyword(s):  
Adenylate Cyclase ◽  
Vasoactive Intestinal Peptide ◽  
Plasma Membranes ◽  
Mononuclear Cells ◽  
Specific Binding ◽  
Thymosin Α1 ◽  
Vip Receptors ◽  
Liver Plasma Membranes ◽  
Blood Mononuclear Cells ◽  
Thymic Peptide

Thymic peptide thymosin α1 (10−9 to 3 × 1010−7 M) is shown to inhibit the specific binding of [125I]VIP to rat blood mononuclear cells and liver plasma membranes. Thymosin α1 was 160 and 6250 times less potent that VIP at inhibiting [125I]VIP binding to blood mononuclear cells and liver plasma membranes, respectively. Thymosin α1 (10−10 to 1010−7 M) was weak in stimulating adenylate cyclase activity. Its efficacy is about 25 % and 27 % that of native VIP in blood mononuclear cells and liver plasma membranes, respectively. Thymosin α1 may behave as a partial VIP agonist in rat.

scholarly journals Lysophosphatidylcholines can modulate the activity of the glucagon-stimulated adenylate cyclase from rat liver plasma membranes

1979 ◽  
Vol 178 (1) ◽  
pp. 217-221 ◽  
Author(s):  
M D Houslay ◽  
R W Palmer
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Hormone Receptors ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes ◽  
Increased Sensitivity

1. Synthetic lysophosphatidylcholines inhibit the glucagon-stimulated adenylate cyclase activity of rat liver plasma membranes at concentrations two to five times lower than those needed to inhibit the fluoride-stimulated activity. 2. Specific 125I-labelled glucagon binding to hormone receptors is inhibited at concentrations similar to those inhibiting the fluoride-stimulated activity. 3. At concentrations of lysophosphatidylcholines immediately below those causing inhibition, an activation of adenylate cyclase activity or hormone binding was observed. 4 These effects are essentially reversible. 5. We conclude that the increased sensitivity of glucagon-stimulated adenylate cyclase to inhibition may be due to the lysophosphatidylcholines interfering with the physical coupling between the hormone receptor and catalytic unit of adenylate cyclase. 6. We suggest that, in vivo, it is possible that lysophosphatidylcholines may modulate the activity of adenylate cyclase only when it is in the hormone-stimulated state.

Effects of 4-hydroxynonenal on adenylate cyclase and 5′-nucleotidase activities in rat liver plasma membranes

1985 ◽  
Vol 53 ◽  
pp. 209-217 ◽  
Author(s):  
Luciana Paradisi ◽  
Carla Panagini ◽  
Maurizio Parola ◽  
Giuseppina Barrera ◽  
Mario U. Dianzani
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes

scholarly journals The effect of fluoride on the state of aggregation of adenylate cyclase in rat liver plasma membranes

1980 ◽  
Vol 188 (1) ◽  
pp. 137-140 ◽  
Author(s):  
B R Martin ◽  
J M Stein ◽  
E L Kennedy ◽  
C A Doberska
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
The State ◽  
Target Size ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes

Irradiation inactivation was used to monitor changes in the state of adenylate cyclase in rat liver plasma membranes in the presence of F-.F- caused a decrease in the target size from 328000 to 237000 at 0 degrees C and from 329000 to 219000 at 30 degrees C. Adenylate cyclase was activated by F- at both 0 degrees C and 30 degrees C. The effect of F- was biphasic, activating up to a concentration of 10mM and inhibiting at higher concentrations. If adenylate cyclase weas maximally activated with glucagon and p[NH]ppG ([beta gamma-imido]GTP) all concentrations of F- were inhibitory. The implications of the results with respect to the mechanism of activation of adenylate cyclase are discussed.

Sign in / Sign up

Export Citation Format

Share Document