Activation of adenylate cyclase by islet amyloid polypeptide with COOH-terminal amide via calcitonin gene-related peptide receptors on rat liver plasma membranes

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.

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A New Calcitonin-Receptor-like Sequence in Rat Pulmonary Blood Vessels

Clinical Science ◽

10.1042/cs0850385 ◽

1993 ◽

Vol 85 (4) ◽

pp. 385-388 ◽

Cited By ~ 108

Author(s):

F. Njuki ◽

C. G. Nicholl ◽

A. Howard ◽

J. C. W. Mak ◽

P. J. Barnes ◽

...

Keyword(s):

Blood Vessels ◽

Vascular Tone ◽

Islet Amyloid Polypeptide ◽

Calcitonin Gene Related Peptide ◽

Binding Activity ◽

Calcitonin Receptor ◽

Islet Amyloid ◽

Related Peptide ◽

Calcitonin Gene

1. Two rat clones have been isolated which are similar to known calcitonin-receptor sequences. One of these does not have the distribution expected of a calcitonin receptor. It is widely distributed, with extremely high levels of expression in the lung, where it is associated with the blood vessels. 2. This rat sequence may represent the receptor for calcitonin-gene-related peptide or islet amyloid polypeptide. Both have binding activity in the lung and are potent vasodilators. The gene represented by this sequence may therefore play an important role in the maintenance of vascular tone.

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The role of lipids in the activity of adenylate cyclase of rat liver plasma membranes

Archives of Biochemistry and Biophysics ◽

10.1016/0003-9861(71)90306-7 ◽

1971 ◽

Vol 147 (1) ◽

pp. 36-40 ◽

Cited By ~ 55

Author(s):

Antal Réthy ◽

Vittorio Tomasi ◽

Agostino Trevisani

Keyword(s):

Adenylate Cyclase ◽

Rat Liver ◽

Plasma Membranes ◽

Liver Plasma Membranes ◽

Rat Liver Plasma Membranes

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The Physiology of Calcitonin Gene?Related Peptide in the Islet Compared with That of Islet Amyloid Polypeptide (Amylin)

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1992.tb22777.x ◽

1992 ◽

Vol 657 (1 Calcitonin Ge) ◽

pp. 299-312 ◽

Cited By ~ 14

Author(s):

D. BRETHERTON-WATT ◽

M. A. GHATEI ◽

H. JAMAL ◽

S. G. GILBEY ◽

P. M. JONES ◽

...

Keyword(s):

Islet Amyloid Polypeptide ◽

Calcitonin Gene Related Peptide ◽

Islet Amyloid ◽

Related Peptide ◽

Calcitonin Gene

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Amylin, calcitonin gene-related peptide, and adrenomedullin: effects on thiazide receptor and calcium

AJP Renal Physiology ◽

10.1152/ajprenal.1997.272.3.f410 ◽

1997 ◽

Vol 272 (3) ◽

pp. F410-F415 ◽

Cited By ~ 2

Author(s):

P. Blakely ◽

D. A. Vaughn ◽

D. D. Fanestil

Keyword(s):

Rat Kidney ◽

Ionic Composition ◽

Islet Amyloid Polypeptide ◽

Calcitonin Gene Related Peptide ◽

Urinary Calcium ◽

Calcium Excretion ◽

Electrolyte Excretion ◽

Islet Amyloid ◽

Related Peptide ◽

Calcitonin Gene

We previously reported that salmon calcitonin, but not rat calcitonin, increased renal thiazide receptor (TZR) density and decreased renal calcium [urinary calcium excretion (U(Caex))] in the rat. Since calcitonins, islet amyloid polypeptide (amylin), calcitonin-gene related peptide (CGRP), and adrenomedullin interact with a family of calcitonin-related receptors, we examined the effects of these peptides on 1) TZR density, as quantitated by binding of [3H]metolazone to renal membranes; 2) plasma ionic composition; and 3) urinary electrolyte excretion. Subcutaneous amylin both increased TZR density nearly twofold and decreased U(Caex), with maximal effects by 24 h. The decreased U(Caex) occurred with plasma amylin levels in the physiological range, whereas the increased TZR did not reach maximum even with plasma amylin >100 times above normal. Similar doses of adrenomedullin increased TZR density modestly but without effect on U(Caex), whereas CGRP did not alter TZR density and tended to increase U(Caex). We propose that U(Caex) and TZR density in the rat kidney are regulated by rat amylin but not by rat calcitonin.

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