Cellular mechanism of sodium oleate-stimulated secretion of cholecystokinin and secretin

2000 ◽  
Vol 279 (2) ◽  
pp. G295-G303 ◽  
Author(s):  
Cecilia H. Chang ◽  
William Y. Chey ◽  
Ta-Min Chang
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Sodium Oleate ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Protein Kinase Ii ◽  
Dependent Protein ◽  
Kinase A ◽  
Cck Release

Long-chain fatty acids are potent stimulants of secretin and CCK release. The cellular mechanisms of fatty acid-stimulated secretion of these two hormones are not clear. We studied the stimulatory effect and mechanism of sodium oleate (SO) on secretin- and CCK-producing cells. SO stimulated the release of secretin or CCK from isolated rat mucosal cell preparations enriched in either secretin- or CCK-producing cells, respectively. SO also time- and dose-dependently stimulated secretin and CCK release from STC-1 cells. In STC-1 cells, SO-stimulated secretin and CCK release was potentiated by IBMX and inhibited by a protein kinase A-selective inhibitor and a cAMP-specific antagonist. SO-stimulated releases of the two hormones were also inhibited by downregulation or inhibitors of protein kinase C, a calmodulin antagonist and an inhibitor of calmodulin-dependent protein kinase II. Chelating of extracellular Ca2+ or addition of an L-type calcium channel blocker diminished SO-stimulated hormone releases. SO caused an increase in intracellular Ca2+ concentration that was partially reversed by diltiazem but had no effect on production of cAMP, cGMP, or inositol-1,4,5-triphosphate. These results indicate that SO acts on secretin- and CCK-producing cells. Its stimulatory effect is potentiated by endogenous protein kinase A and mediated by activation of Ca2+ influx through the L-type channels and of protein kinase C and Ca2+/calmodulin-dependent protein kinase II.

scholarly journals Nonclassical Mechanisms of Progesterone Action in the Brain: II. Role of Calmodulin-Dependent Protein Kinase II in Progesterone-Mediated Signaling in the Hypothalamus of Female Rats

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5518-5526 ◽  
Author(s):  
Bhuvana Balasubramanian ◽  
Wendy Portillo ◽  
Andrea Reyna ◽  
Jian Zhong Chen ◽  
Anthony N. Moore ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Female Rats ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Dependent Protein ◽  
The Brain ◽  
Kinase A

In addition to the activation of classical progestin receptor-dependent genomic pathway, progesterone (P) can activate nonclassical, membrane-initiated signaling pathways in the brain. We recently demonstrated rapid P activation of second-messenger kinases, protein kinase A, and protein kinase C in the ventromedial nucleus (VMN) and preoptic area (POA) of rat brain. To determine whether P can activate yet another Ca+2dependent kinase, we examined the rapid P modulation of calcium and calmodulin-dependent protein kinase II (CaMKII) in the VMN and POA in female rats. A rapid P-initiated activation of CaMKII basal activity was observed in the VMN but not the POA at 30 min. Estradiol benzoate (EB) priming enhanced this CaMKII basal activity in both the VMN and POA. CaMKII protein levels and phosphorylation of Thr-286 moiety on CaMKII, however, remained unchanged with EB and/or P treatments, suggesting that the changes in the CaMKII kinase activity are due to rapid P modulation of the kinase activity and not its synthesis or autoactivation. Furthermore, intracerebroventricular (icv) administration of a CaMKII-specific inhibitor, KN-93, 30 min prior to the P infusion, in EB-primed, ovariectomized female rats inhibited CaMKII activation but not protein kinase A and protein kinase C activities. Interestingly, icv administration of KN-93 30 min prior to P infusion (icv) resulted in a reduction but not total inhibition of P-facilitated lordosis response in EB-primed female rats. These observations suggest a redundancy or, alternately, a hierarchy in the P-regulated activation of kinase signaling cascades in female reproductive behavior.

scholarly journals v-ras and protein kinase C dedifferentiate thyroid cells by down-regulating nuclear cAMP-dependent protein kinase A.

1992 ◽  
Vol 6 (9) ◽  
pp. 1621-1630 ◽  
Author(s):  
A Gallo ◽  
E Benusiglio ◽  
I M Bonapace ◽  
A Feliciello ◽  
S Cassano ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Dependent Protein Kinase ◽  
Thyroid Cells ◽  
Camp Dependent Protein Kinase ◽  
Kinase C ◽  
Dependent Protein ◽  
Kinase A

Distinct voltage-dependent regulation of a heart-delayed IK by protein kinases A and C

1991 ◽  
Vol 261 (6) ◽  
pp. C1081-C1090 ◽  
Author(s):  
K. B. Walsh ◽  
R. S. Kass
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Voltage Dependent ◽  
Dependent Protein ◽  
Kinetics Of ◽  
Kinase A ◽  
Stimulation Of

We have investigated the effects of stimulation of adenosine 3',5'-cyclic monophosphate-dependent protein kinase (protein kinase A) and Ca(2+)-diacylglycerol-dependent protein kinase (protein kinase C) on the delayed rectifier K+ current (IK) in guinea pig ventricular cells using a whole cell arrangement of the patch-clamp procedure. Stimulation of either protein kinase C or A resulted in enhanced IK activity. Augmentation of IK observed during stimulation of protein kinase A occurred in a markedly voltage-dependent manner, with the largest increases occurring at potentials near the threshold for IK activation. Enhancement of IK during stimulation of protein kinase C followed a different pattern, with minimal effects of the enzyme near IK threshold. Neither protein kinase A nor C altered the kinetics of IK activation, although both kinases slightly changed the kinetics of deactivation. Both kinases increased IK maximal conductance, but the effects of each kinase on the voltage-dependence of activation differed. Protein kinase A shifted IK activation toward more negative voltages but did not affect the slope of the activation curve. Protein kinase C, in contrast, changed the slope of the IK activation curve, with only a small effect on the half-maximal voltage of activation. These contrasting effects on the voltage dependence of IK activation are consistent with actions of the kinases at distinct sites on or near the IK channel protein.

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