TY - JOUR
T1 - Human growth hormone-stimulated mitogenesis of Nb2 node lymphoma cells is not mediated by an immediate acceleration of phosphoinositide metabolism
AU - Gertler, Arieh
AU - Friesen, Henry G.
PY - 1986/12
Y1 - 1986/12
N2 - Lactogenic hormones stimulate the mitogenesis of Nb2-11C rat lymphoma cells and this stimulation is enhanced by 12-O-tetradecanoyl phorbol ester (TPA). The effect of human growth hormone (hGH) and TPA on phosphoinositide metabolism in Nb2-11C cells was tested by measuring the incorporation of [3H] myo-inositol or 32P or measuring the breakdown of polyphosphoinositides in cells prelabeled with [3H] myo-inositol, 32P or [3H]arachidonic acid. We found that none of these processes is immediately stimulated by either hGH and/or TPA. Our results indicate that the overall phosphoinositide turnover is slow or confined to small fractions only. On the other hand, the phosphorylation-dephosphorylation cycle of polyphosphoinositides is quite fast and remarkably exceeds the rate of incorporation of [3H]wyo-inositol. Our present results indicate, therefore, that the mitogenic effect of hGH and its enhancement by TPA is not mediated by an immediate increase in phosphoinositide metabolism.
AB - Lactogenic hormones stimulate the mitogenesis of Nb2-11C rat lymphoma cells and this stimulation is enhanced by 12-O-tetradecanoyl phorbol ester (TPA). The effect of human growth hormone (hGH) and TPA on phosphoinositide metabolism in Nb2-11C cells was tested by measuring the incorporation of [3H] myo-inositol or 32P or measuring the breakdown of polyphosphoinositides in cells prelabeled with [3H] myo-inositol, 32P or [3H]arachidonic acid. We found that none of these processes is immediately stimulated by either hGH and/or TPA. Our results indicate that the overall phosphoinositide turnover is slow or confined to small fractions only. On the other hand, the phosphorylation-dephosphorylation cycle of polyphosphoinositides is quite fast and remarkably exceeds the rate of incorporation of [3H]wyo-inositol. Our present results indicate, therefore, that the mitogenic effect of hGH and its enhancement by TPA is not mediated by an immediate increase in phosphoinositide metabolism.
KW - human growth hormone stimulated
KW - mitogenesis
KW - Nb2 node lymphoma cell
KW - phosphoinositide metabolism acceleration
UR - http://www.scopus.com/inward/record.url?scp=0022971219&partnerID=8YFLogxK
U2 - 10.1016/0303-7207(86)90045-6
DO - 10.1016/0303-7207(86)90045-6
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C2 - 3026872
AN - SCOPUS:0022971219
SN - 0303-7207
VL - 48
SP - 221
EP - 228
JO - Molecular and Cellular Endocrinology
JF - Molecular and Cellular Endocrinology
IS - 2-3
ER -