Repeated Exposure of Adult Rats to Aroclor 1254 Causes Brain Region-Specific Changes in Intracellular Ca2+Buffering and Protein Kinase C Activity in the Absence of Changes in Tyrosine Hydroxylase

1998 ◽  
Vol 153 (2) ◽  
pp. 186-198 ◽  
Author(s):  
Prasada Rao S. Kodavanti ◽  
Ethel C. Derr-Yellin ◽  
William R. Mundy ◽  
Timothy J. Shafer ◽  
David W. Herr ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Tyrosine Hydroxylase ◽  
Protein Kinase ◽  
Brain Region ◽  
Repeated Exposure ◽  
Aroclor 1254 ◽  
Adult Rats ◽  
Kinase C ◽  
Protein Kinase C Activity

Cognition stimulating drugs modulate protein kinase C activity in cerebral cortex and hippocampus of adult rats

Life Sciences ◽  
1993 ◽  
Vol 53 (24) ◽  
pp. 1821-1832 ◽  
Author(s):  
Laura Lucchi ◽  
Alessia Pascale ◽  
Fiorenzo Battaini ◽  
Stefano Govoni ◽  
Marco Trabucchi
Keyword(s):  
Cerebral Cortex ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Adult Rats ◽  
Kinase C ◽  
Protein Kinase C Activity

Human interleukin 1β stimulates islet insulin release by a mechanism not dependent on changes in phospholipase C and protein kinase C activities or Ca2+ handling

1989 ◽  
Vol 121 (5) ◽  
pp. 698-704 ◽  
Author(s):  
Nils Welsh ◽  
Thomas Nilsson ◽  
Anders Hallberg ◽  
Per Arkhammar ◽  
Per-Olof Berggren ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Phosphorylation ◽  
Phospholipase C ◽  
Insulin Release ◽  
Interleukin 1Β ◽  
High Concentration ◽  
Adult Rats ◽  
Kinase C ◽  
Protein Kinase C Activity

Abstract. Isolated islets from adult rats or obese hyperglycemic (ob/ob) mice were incubated with human recombinant interleukin 1β in order to study whether the acute effects of the cytokine on islet insulin release are associated with changes in islet phospholipase C activity, Ca2+ handling or protein phosphorylation. The cytokine stimulated insulin release both at low and high glucose concentrations during one hour incubations. In shortterm incubations (<1 min) interleukin 1β did not affect the production of inositoltrisphosphate. Addition of interleukin 1β affected neither the cytoplasmic free Ca2+ concentration at rest nor that observed subsequent to stimulation with a high concentration of glucose. Furthermore, the endogenous protein kinase C activity, as visualized by immunoprecipitation of a 32P-labelled substrate for this enzyme, was not altered by interleukin 1β. Separation of 32P-labelled proteins by means of 2-dimensional gel electrophoresis failed to reveal any specific effects of the cytokine on the total protein phosphorylation activity. These results suggest that the stimulatory effects on insulin release exerted by interleukin 1β are not caused by acute activation of phospholipase C and protein kinase C or by an alteration of islet Ca2+ handling of the B-cells.

Chronic treatment by the calcium channel blocker ± PN 200-110 in the rat counteracts the stimulations of pituitary weight, prolactin release and pituitary C-kinase activity induced by a chronic estradiol treatment, in vivo

1990 ◽  
Vol 122 (3) ◽  
pp. 403-408
Author(s):  
Ph. Touraine ◽  
P. Birman ◽  
F. Bai-Grenier ◽  
C. Dubray ◽  
F. Peillon ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Channel Blocker ◽  
Plasma Prolactin ◽  
Estradiol Treatment ◽  
Kinase C ◽  
Protein Kinase C Activity

Abstract In order to investigate whether a calcium channel blocker could modulate the protein kinase C activity in normal and estradiol pretreated rat pituitary, female Wistar rats were treated or not (controls) with ± PN 200-110 (3 mg · kg−1 · day−1, sc) for 8 days or with estradiol cervical implants for 8 or 15 days, alone or in combination with PN 200-110 the last 8 days. Estradiol treatment induced a significant increase in plasma prolactin levels and pituitary weight. PN 200-110 administered to normal rats did not modify these parameters, whereas it reduced the effects of the 15 days estradiol treatment on prolactin levels (53.1 ± 4.9 vs 95.0 ±9.1 μg/l, p<0.0001) and pituitary weight (19.9 ± 0.4 vs 23.0 ± 0.6 mg, p <0.001), to values statistically comparable to those measured after 8 days of estradiol treatment. PN 200-110 alone did not induce any change in protein kinase C activity as compared with controls. In contrast, PN 200-110 treatment significantly counteracted the large increase in soluble activity and the decrease in the particulate one induced by estradiol between day 8 and day 15. We conclude that PN 200-110 opposed the stimulatory effects of chronic in vivo estradiol treatment on plasma prolactin levels and pituitary weight and that this regulation was related to a concomitant modulation of the protein kinase C activity.

Swainsonine Modulation of Protein Kinase C Activity in Murine Peritoneal Macrophages

1990 ◽  
Vol 2 (10) ◽  
pp. 333-338 ◽  
Author(s):  
Pascal Breton ◽  
Amha Asseffa ◽  
Krzysztof Grzegorzewski ◽  
Steven K. Akiyama ◽  
Sandra L. White ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Peritoneal Macrophages ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Murine Peritoneal Macrophages

Effect of phorbol myristate acetate on secretion of parathyroid hormone

1988 ◽  
Vol 254 (1) ◽  
pp. E63-E70 ◽  
Author(s):  
J. J. Morrissey
Keyword(s):  
Protein Kinase C ◽  
Parathyroid Hormone ◽  
Protein Kinase ◽  
Membrane Fraction ◽  
Hormone Secretion ◽  
Myristate Acetate ◽  
Kinase C ◽  
Low Calcium ◽  
Protein Kinase C Activity ◽  
High Calcium

The influence of phorbol myristate acetate (PMA), an activator of protein kinase c, on the secretion of parathyroid hormone from collagenase-dispersed bovine parathyroid cells was tested. The cells were incubated at low (0.5 mM) or high (2.0 mM) concentrations of calcium in the medium, and the hormone secreted into the medium was measured by a radioimmunoassay that recognizes both intact and C-terminal fragments of hormone. At low calcium, the secretory rate averaged 32 +/- 3.8 ng.h-1.(10(5) cells)-1. The addition of 1.6 microM PMA did not affect secretion. At high calcium there was a significant suppression of secretion by 38% to 19.8 +/- 3 ng.h-1.(10(5) cells)-1. The addition of 1.6 microM PMA significantly stimulated hormone secretion to 35.8 +/- 8 ng.h-1.(10(5) cells)-1, a rate indistinguishable from low calcium. This stimulatory effect of PMA at high calcium was seen at PMA concentrations as low as 1.6 nM, did not occur with a biologically inactive 4 alpha-isomer of phorbol ester, and was independent of changes in cellular adenosine 3',5'-cyclic monophosphate levels. Examination of 32P-labeled phosphoproteins by two-dimensional gel electrophoresis revealed acidic proteins of approximately 20,000 and 100,000 Da that were phosphorylated at low and high calcium + 1.6 microM PMA but not at high calcium alone. The protein kinase c activity associated with the membrane fraction of parathyroid cells significantly decreased 40% when the cells were incubated at high vs. low calcium. The data suggest that calcium may regulate parathyroid hormone secretion through changes in protein kinase c activity of the membrane fraction of the cell and protein phosphorylation.

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