INVESTIGADORES
VENTURINO Andres
artículos
Título:
Histamine receptors in an experimental mammary carcinoma
Autor/es:
RIVERA, ES; DAVIO CA; VENTURINO A; CARO RA; BERGOC R.M.
Revista:
BIOMEDICINE & PHARMACOTHERAPY = BIOMEDECINE & PHARMACOTHERAPIE.
Editorial:
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
Referencias:
Lugar: Paris; Año: 1994 vol. 48 p. 399 - 406
ISSN:
0753-3322
Resumen:
An experimental mammary carcinoma was induced in
Sprague-Dawley rats by the ip administration of N-nitroso-N-methylurea (NMU) in
three doses of 50 mg/kg. In order to study the expression of histamine
receptors in these experimental tumors, the presence of specific binding sites
for histamine was studied. Using [3H]-histamine as a radioligand,
two specific binding sites were characterized on the cell membrane. The first
site, of high affinity, Kd = 4 ± 2 nM,
was further characterized as an H2 type using [3H]-cimetidine and [3H]-tiotidine
as radioligands and by displacement experiments with different histamine
agonists and antagonists. The second one of low affinity, Kd = 35 ± 14 nM, needs further
characterization. The determination of cAMP levels showed that histamine and
the H2 agonist dimaprit, produced a significant decrease in the nucleotide
concentration 6 minutes after stimulation, in a response that was specifically
abolished by H2 antagonists. Based on these results, we conclude that
neoplastic cells from NMU induced tumors express H2 histamine membrane
receptors which are coupled to a transductional pathway different from cAMP
production, which may be involved in the regulation of tumor growth.