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.

Mitogen stimulation of Na+-H+ exchange: differential involvement of protein kinase C

1987 ◽  
Vol 253 (2) ◽  
pp. C219-C229 ◽  
Author(s):  
L. L. Muldoon ◽  
G. A. Jamieson ◽  
A. C. Kao ◽  
H. C. Palfrey ◽  
M. L. Villereal
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Types ◽  
Intact Cells ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Human Fibroblast Strains ◽  
Stimulation Of

The mitogen-induced activation of Na+-H+ exchange was investigated in two cultured human fibroblast strains (HSWP and WI-38 cells) that, based on previous studies, differed in their response to the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) (L. M. Vincentini and M. L. Villereal, Proc. Natl. Acad. Sci. USA 82: 8053-8056, 1985). The role of protein kinase C in the activation of Na+-H+ exchange was investigated by comparing the effects of TPA on Na+ influx, in vitro phosphorylation, and in vivo phosphorylation in both cell types. Although both cell types have significant quantities of protein kinase C activity that can be activated by TPA in intact cells, the addition of TPA to intact cells stimulates Na+ influx in WI-38 cells but not in HSWP cells, indicating that in HSWP cells the stimulation of protein kinase C is not sufficient to activate the Na+-H+ exchanger. Cells were then depleted of protein kinase C activity by chronic treatment with high doses of TPA. Both HSWP and WI-38 cells were rendered protein kinase C deficient by this treatment as determined by in vitro and in vivo phosphorylation studies. Protein kinase C-deficient HSWP cells lose the ability for TPA to inhibit the serum-induced activation of Na+-H+ exchange, but there is no reduction in the stimulation of Na+ influx by serum, bradykinin, vasopressin, melittin, or vanadate, indicating that protein kinase C activity is not necessary for the mitogen-induced activation of Na+-H+ exchange in HSWP cells by agents known to stimulate phosphatidylinositol turnover (G. A. Jamieson and M. Villereal. Arch. Biochem. Biophys. 252: 478-486, 1987). In contrast, depletion of protein kinase C activity in WI-38 cells significantly reduces both the TPA- and the serum-induced activation of the Na+-H+ exchange system, suggesting that protein kinase C activity is necessary for at least a portion of the mitogen-induced activation of the Na+-H+ exchanger in WI-38 cells. These results indicate that the mechanisms for regulating Na+-H+ exchange can differ dramatically between different types of fibroblasts.

A vitamin D analogue KH 1060 activates the protein kinase C– c-fos signalling pathway to stimulate epidermal proliferation in murine skin

1994 ◽  
Vol 143 (3) ◽  
pp. 521-525 ◽  
Author(s):  
R Gniadecki
Keyword(s):  
Vitamin D ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Topical Application ◽  
Messenger Rna ◽  
Hairless Mouse ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Epidermal Growth

Abstract The cellular signalling pathways of a potent 20-epi-22-oxa vitamin D3 analogue (KH 1060) were examined in vivo in a hairless mouse model. Seventy two hours after a single topical application of KH 1060 a thickening of the epidermis (from 24·8 ±1·2 μm at 0·01 pmol/cm2 KH 1060 to 124·2 ± 6 μm at 5 pmol/cm2 KH 1060, P<0·001) was elicited due to epidermal hyperproliferation. This effect could be blocked by topical 2·5 μmol/cm sphingosine, an inhibitor of protein kinase C. Two hours after topical application of 2·5 pmol/cm2 KH 1060 a translocation of protein kinase C activity from cytoplasm to the membrane fractions was observed. Moreover, using a reverse-transcription polymerase chain reaction technique, a transient upregulation of c-fos gene expression was seen 2 hours after topical treatment with KH 1060. The expression of c-fos was dependent on protein kinase C activation, since after pretreatment with the protein kinase C blocker sphingosine, c-fos messenger RNA was not detected. These findings strongly suggest that KH 1060 stimulates epidermal growth through activation of the protein kinase C - c-fos signalling axis in vivo. Journal of Endocrinology (1994) 143, 521–525

Estradiol Modulates Protein Kinase C Activity in the Rat Pituitary in Vivo and in Vitro

Endocrinology ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 536-544 ◽  
Author(s):  
S. V. DROUVA ◽  
I. GORENNE ◽  
E. LAPLANTE ◽  
E. RERAT ◽  
A. ENJALBERT ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Rat Pituitary

scholarly journals Correction of abnormal small intestinal cytosolic protein kinase C activity in streptozotocin-induced diabetes by insulin therapy

1990 ◽  
Vol 272 (3) ◽  
pp. 653-658 ◽  
Author(s):  
R K Wali ◽  
P K Dudeja ◽  
M J G Bolt ◽  
M D Sitrin ◽  
T A Brasitus
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Total Protein ◽  
De Novo ◽  
Diabetic Rats ◽  
Insulin Administration ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Streptozotocin Induced Diabetes

Diabetes was induced in rats by administration of a single intraperitoneal injection of streptozotocin (50 mg/kg body wt). After 7 days, one group of diabetic animals was treated with insulin for an additional 5 days. Control, diabetic and diabetic + insulin rats were then killed, their distal small intestines were removed and the epithelial cells were examined and compared with respect to polyphosphoinositide turnover, total protein kinase C activity and cellular distribution, and 1,2-diacylglycerol mass and production. The results of these experiments demonstrated that, compared with their control counterparts, the intestines from diabetic rats had a decreased turnover of polyphosphoinositides, but an increase in 1,2-diacylglycerol mass which was a result, at least in part, of an increase in the synthesis of this lipid de novo. Total protein kinase C activity was decreased in the diabetic rats due to a decrease in cytosolic activity, with no significant change in particulate activity. Moreover, insulin administration for 5 days to diabetic animals did not affect their lowered intestinal polyphosphoinositide turnover, but did further accentuate their increased 1,2-diacylglycerol mass and synthesis de novo; this treatment also corrected total protein kinase C activity by increasing the cytosolic activity of this enzyme. These results indicate that signalling mechanisms involving polyphosphoinositides, 1,2-diacylglycerol and protein kinase C are abnormal in the intestines of diabetic rats and that some of these biochemical parameters can be modulated by insulin administration in vivo.

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