Interleukin 1 beta inhibition of TRH-stimulated prolactin secretion and phosphoinositides metabolism.
The effect of interleukin 1 beta on prolactin secretion and on phosphoinositide turnover in anterior pituitary cells was evaluated. Interleukin 1 beta significantly inhibited TRH-stimulated prolactin secretion assessed by the reverse hemolytic plaque assay. In particular, the cytokine reduced the percentage of plaque forming cells, the plaque mean area, the large plaques percentage. TRH-stimulated inositol phosphate production was also significantly inhibited by interleukin 1 beta. This study shows that interleukin 1 beta reduces TRH-induced prolactin secretion through a direct action on pituitary cell, and attenuates the TRH-stimulated phosphoinositide breakdown. This latter effect may suggest that the reduced lactotropes sensitivity to TRH action may be partially due to interleukin 1 beta inhibition of phosphatidylinositol breakdown.
Schettini
G
G
Institute of Pharmacology, II School of Medicine, University of Naples, Italy.
Landolfi
E
E
Grimaldi
M
M
Meucci
O
O
Postiglione
A
A
Florio
T
T
Ventra
C
C
D000818:Animals; D002478:Cells, Cultured; D006462:Hemolytic Plaque Technique; D007295:Inositol Phosphates / Q000378:metabolism*; D007375:Interleukin-1 / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D010716:Phosphatidylinositols / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011994:Recombinant Proteins / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D007295:Inositol Phosphates; D007375:Interleukin-1; D010716:Phosphatidylinositols; D011994:Recombinant Proteins; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin