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A M Kaye

Publications and source records attributed to A M Kaye.

At least 55 records · Page 3Linked to original sources
PubMed1987

Parathyroid hormone induction of creatine kinase activity and DNA synthesis is mimicked by phospholipase C, diacylglycerol and phorbol ester.

Parathyroid hormone (PTH), which increases cAMP levels, also induces an increase in the activity of the brain isozyme of creatine kinase and in DNA synthesis in osteoblast-enriched bone cell cultures by a cAMP-independent mechanism. The following results lead us to the conclusion that PTH induction of brain isozyme of creatine kinase activity and DNA synthesis occurs by activation of membranal phospholipid metabolism leading to increased protein kinase C activity and Ca2+ mobilization, a mechanism demonstrated for several growth factors and other hormones. (1) Binding of membranal phospholipids by agents such as gentamycin or antiphospholipid antibodies abolishes the stimulation by PTH of creatine kinase activity and DNA synthesis but not of cAMP production. (2) Treatment of cell cultures with exogenous phospholipase C increases brain isozyme of creatine kinase activity and DNA synthesis, but not cAMP production; these stimulations are also blocked by serum containing anti-phospholipid antibodies. PTH has no additional effect on stimulation of creatine kinase activity by phospholipase C (and only a slight effect on DNA synthesis). (3) A synthetic diacylglycerol (1-oleyl-2-acetyl glycerol) or phorbol ester (phorbol 12-myristate 13-acetate) or Ca2+ ionophore, A23187 induces creatine kinase activity and DNA synthesis in the cultures. However, this effect is not blocked by antiphospholipid sera and PTH has no additional effect. (4) Inhibition of protein kinase C activity by drugs reported to inhibit the enzyme (retinoic acid, quercetin) abolishes the stimulation of brain isozyme of creatine kinase activity and of DNA synthesis by PTH.

Animals↗
PubMed1987

31P-NMR studies of phosphate transfer rates in T47D human breast cancer cells.

The concentration of phosphates and the kinetics of phosphate transfer reactions were measured in the human breast cancer cell line, T47D, using 31P-NMR spectroscopy. The cells were embedded in agarose filaments and perifused with oxygenated medium during the NMR measurements. The following phosphates were identified in spectra of perifused cells and of cell extracts: phosphorylcholine (PC), phosphorylethanolamine (PE), the glycerol derivatives of PC and PE, inorganic phosphate (Pi), phosphocreatine (PCr), nucleoside triphosphate (primarily ATP) and uridine diphosphate glucose. The rates of the transfers: PC----gamma ATP (0.2 mM/s), Pi----gamma ATP (0.2 mM/s) and the conversion beta ATP----beta ADP (1.3 mM/s) were determined from analysis of data obtained in steady-state saturation transfer and inversion recovery experiments. Data from spectrophotometric assays of the specific activity of creatine kinase (approx. 0.1 mumol/min per mg protein) and adenylate kinase (approx. 0.4 mumol/min per mg protein) suggest that the beta ATP----beta ADP rate is dominated by the latter reaction. The ratio between the rate of ATP synthesis from Pi and the rate of consumption of oxygen atoms (4 X 10(-3) mM/s) was approx. 50. This high value and preliminary measurements of the rate of lactate production from glucose, indicated that aerobic glycolysis is the main pathway of ATP synthesis.

Adenosine Diphosphate↗
PubMed1987

Developmental changes in responsiveness to vitamin D metabolites.

We have demonstrated that epiphyseal chondroblasts contain specific receptors for 24R,25-dihydroxy vitamin D3(24,25(OH)2D3) while diaphyseal osteoblasts contain specific receptors for 1 alpha 25-dihydroxy vitamin D3(1,25(OH)2D3). Both metabolites induce DNA synthesis and creatine kinase (CKBB) activity. We have also found that the responsiveness of rat kidney to these metabolites changes during development. In embryonic and early postnatal stages, the kidney responds to 24,25(OH)2D3, later to both 24,25(OH)2D3 and 1,25(OH)2D3, and the mature kidney only to 1,25(OH)2D3. These responses correlate with changes in the specific receptors present in the kidney. Furthermore, we have compared developmental changes in skeletal (epiphysis, diaphysis and mandibular condyle) and non-skeletal (kidney, cerebellum, cerebrum, liver and pituitary) tissue in both rat (a postnatal developer) and rabbit (a perinatal developer). Epiphyseal or diaphyseal chondroblasts at any stage of development were predominantly responsive to 24,25(OH)2D3, whereas osteoblasts were responsive to 1,25(OH)2D3. In contrast, condylar chondroblasts, kidney, cerebellum and pituitary responded to 24,25(OH)2D3 during early development and subsequently developed responsiveness to 1,25(OH)2D3. Using primary cell cultures from kidneys at different stages of maturation, we showed the same developmental pattern as in vivo. Chronic treatment of the cells with 24,25(OH)2D3, but not 1,25(OH)2D3, caused precocious development of responsiveness to 1,25(OH)2D3 in culture. We suggest that 24,25(OH)2D3 acts as a maturation factor, during early development in kidney, and probably in other tissues, possibly by induction of receptor to 1,25(OH)2D3, accompanied by down-regulation of its own receptor.

24,25-Dihydroxyvitamin D 3↗
PubMed1986

31P NMR studies of adenosine-stimulated ATP synthesis in perfused luteinized ovaries.

31P NMR spectroscopy was utilized to study phosphate metabolism of perfused ovaries. In luteinized ovaries, a loss in ATP of approximately 30% with a concomitant acidification was reversed by 50 microM adenosine. The results suggest that in the ovaries, adenosine can serve to regulate ATP concentration during periodic hypoxic challenges.

Adenosine↗
PubMed1986

Developmental changes in the responsiveness of rat kidney to vitamin D metabolites.

Kidneys from both normal and vitamin D-deficient rats were found to show changes in responsiveness to vitamin D metabolites during postnatal development, correlated with the concentrations of the specific receptor for 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or the specific binding protein for 24R,25-dihydroxyvitamin D3 [24,25(OH)2D3]. Cytosol preparations from kidneys of vitamin D-deficient rats, in the second week of life, contained specific binding proteins for 24,25-(OH)2D3. From the fourth week of life, specific receptors for 1,25(OH)2D3 were predominant. In the third week after birth, both the receptor for 1,25(OH)2D3 and the 24,25(OH)2D3 binding protein were present. We have used a sensitive parameter for vitamin D action, the stimulation of creatine kinase BB (CKBB) activity, to measure the response of kidneys from vitamin D-deficient or normal rats. In the first days of life of vitamin D-deficient rats, the kidneys did not respond to either vitamin D metabolite; in the second week of life, there was stimulation of renal CKBB only by 24R,25(OH)2D3; beginning in the fourth week of life, only 1,25(OH)2D3 stimulated renal CKBB. However, during the third week of life, CKBB activity was increased by both metabolites. In normal animals, which showed a lower CK activity at all ages, the response was similar to that in vitamin D-deficient animals but the peak was achieved a few days later. The stimulation of CKBB by vitamin D metabolites occurred in all the zones of the kidneys. An increase in renal CKBB by 1,25(OH)2D3 was also detected immunohistochemically. The increase of CKBB activity caused by the two vitamin D metabolites at different stages of development, closely correlated with changes in the presence of the 1,25(OH)2D3 receptor or the 24,25(OH)2D3 binding protein, suggests a specific role for each metabolite during renal development.

24,25-Dihydroxyvitamin D 3↗
PubMed1986

Stimulation of creatine kinase activity in rat organs by human growth hormone in vivo and in vitro.

Intraperitoneal injection of human GH (hGH) (4 micrograms/g BW) into 21-day-old rats causes, 24 h later, an increase in creatine kinase (CK) specific activity in kidney (1.7-fold), liver (1.6-fold), and in epiphyseal cartilage (1.8-fold). Similar stimulation was obtained when tissue explants were incubated for 24 h with hGH (1 microgram/ml); CK activity rose 1.8-fold in kidney, 1.9-fold in the liver, and 2.6-fold in epiphyseal cartilage. Highly significant stimulation of CK specific activity was obtained in these same organs in hypophysectomized rats. The increase in CK specific activity in the kidney, to some extent in the liver, but not in the epiphyseal cartilage, was also obtained on in vivo treatment with either human placental lactogen or ovine PRL. Stimulation of CK in these three organs by hGH is followed by a parallel increase in DNA synthesis. Dexamethasone, which was also found to increase CK activity in rat kidney and liver, did not affect the increase of CK by hGH in the kidney, stimulated the effect of hGH in the liver, and partially inhibited the effect of hGH in the epiphyseal cartilage. Diethylaminoethyl cellulose chromatography revealed that the basal and induced activity of CK in all cases was due to the brain type isozyme. On the basis of this evidence for a direct effect of hGH on CK brain type activity, we suggest that its stimulation is potentially a convenient and sensitive assay for biological activity of GH.

Animals↗
PubMed1986

Stimulation of creatine kinase activity by calcium-regulating hormones in explants of human amnion, decidua, and placenta.

We have used stimulation of the activity of the brain type creatine kinase (CK) isoenzyme as a response marker to examine the effects of vitamin D metabolites, PTH, and calcitonin in cultured explants of placenta, decidua, and amnion from normal human deliveries. We found a biological response to PTH in placenta and amnion and to vitamin D metabolites in all three tissues. In the amnion, CK activity increased 2.3-fold after 24 h of incubation in 2.5 nM 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], 3.8-fold when incubated with 12.5 nM 24,25-dihydroxyvitamin D3 [24,25-(OH)2D3] and 2.7-fold when incubated with 10 U/ml bovine PTH. In the decidua, 24,25-(OH)2D3, but not 1,25-(OH)2D3 or bPTH caused a 1.7-fold increase in CK activity. In contrast, the placenta responded to 1,25-(OH)2D3 with a 1.6-fold increase in CK activity and to bPTH, with a 1.7-fold increase but did not respond to 24,25-(OH)2D3. Bovine calcitonin (100 ng/ml) had no effect on CK activity in any of the three tissues. Nearly all CK in both the unstimulated and stimulated explants was the brain type isoenzyme. CK activity increased significantly between 1 and 4 h after hormonal treatment in all experiments. The enzyme activity rose steeply with dose and reached a significant increase, and usually a plateau, at hormone concentrations considered to be physiological in vivo. [3H]Thymidine incorporation into DNA increased in parallel to stimulation of CK activity in all experiments, except that PTH did not increase DNA synthesis in the placenta. PTH did cause an increase in cAMP production in explants of amnion (1.5-fold) and placenta (2.6-fold).

Amnion↗
PubMed1985

Stimulation of creatine kinase BB activity by parathyroid hormone and by prostaglandin E2 in cultured bone cells.

Bone cells in culture responded to parathyroid hormone (PTH) and prostaglandin E2 (PGE2) by a 2-fold increase in creatine kinase (CK) activity. Combined treatment resulted in a higher response than with PTH alone. Calcitonin (CT) failed to stimulate CK activity, did not affect the response of CK to PTH, but inhibited slightly the increase in CK activity by PGE2. Bone-cell cultures grown in low [Ca2+] (0.125 mM), enriched in PTH-responsive osteoblast-like cells, responded to PTH, but not to PGE2 or CT, by increased CK activity. In both normal and low-[Ca2+] cultures, 8-bromo cyclic AMP did not affect CK activity, nor did it change the response of the cells to PTH, PGE2 or CT. The increase in CK activity was time- and dose-dependent and inhibited both by cycloheximide and by actinomycin D. The isoenzyme of CK stimulated was the CKBB form, the isoenzyme induced by other hormones. This appears to be the first report of the stimulation of CK activity by a polypeptide hormone or a prostaglandin. We suggest that stimulation of CKBB can serve as a marker for the action of a variety of hormones and growth promoters.

Animals↗
PubMed1985

Regulation of creatine kinase activity in rat osteogenic sarcoma cell clones by parathyroid hormone, prostaglandin E2, and vitamin D metabolites.

We have previously shown that both parathyroid hormone (PTH) and prostaglandin E2 (PGE2) stimulate the activity of creatine kinase BB (CKBB) in rat bone cells in culture. Therefore, morphologically distinct rat osteogenic sarcoma cells in culture were tested for stimulation of CKBB activity by hormones that regulate skeletal tissues. PTH stimulated CKBB in the osteoblast-like clone ROS 17/2; 1 alpha,25(OH)2D3 inhibited this activity while PGE2, CT and 24R,25(OH)2D3 had no significant effect. PGE2 stimulated CKBB activity in the fibroblast-like clone ROS 24/1, which was unresponsive to PTH, CT and Vitamin D metabolites. 24R,25(OH)2D3 as well as PGE2 (but not PTH, CT or 1 alpha 25(OH)2D3) stimulated CKBB in clone ROS 25/1, suggesting that this fibroblast-like clone has some chondroblast-like character. Both PTH and PGE2 stimulated the brain type isoenzyme of CK (CKBB), although the osteogenic sarcoma cell clones contain a significant proportion of the muscle type of CK (CKMM). Thus, increased CKBB activity can serve as an additional characteristic marker for the action of steroid and polypeptide hormones and for prostaglandins.

24,25-Dihydroxyvitamin D 3↗
PubMed1984

Estrogen-induced changes in high-energy phosphate metabolism in rat uterus: 31P NMR studies.

Changes in the concentrations of high-energy phosphate metabolites were measured by 31P NMR spectroscopy of surviving rat uteri from 0-48 h following estrogen administration. Concentrations (millimoles per kilogram wet weight) of these metabolites in the untreated immature uterus, measured at 4 degrees C, were found to be the following: creatine phosphate (CP), 2.1 +/- 0.2; nucleoside triphosphates, mainly adenosine 5'-triphosphate (ATP), 4.6 +/- 0.4; phospho monoesters, primarily sugar phosphates (SP), 5.4 +/- 0.7; and inorganic phosphate (Pi), 0.8 +/- 0.4. Adenosine 5'-diphosphate (ADP) concentration was estimated to be approximately 40 mumol/kg wet weight from the assumed equilibrium of the creatine kinase reaction. The concentration of CP, and to lesser extent ATP and SP, declined within the first 1.5-3 h after injection of 17 beta-estradiol, returned to control values between 6 and 12 h, and then increased, reaching maximal concentrations at 24 h. From the fractions of the total soluble ATP in free and Mg2+-bound forms, [free Mg2+] in the untreated uterus was estimated to be 0.2-0.4 mmol/kg wet weight. An increase in [free Mg2+] in the uterus was detected 1.5 h after estrogen injection. A subsequent parallel increase in the ratio of ATP to CP concentrations suggests that estrogen can also affect the apparent creatine kinase equilibrium by modulating [free Mg2+].

Adenosine Diphosphate↗
PubMed1984

Stimulation of creatine kinase BB activity by 1 alpha,25-dihydroxycholecalciferol and 24R,25-dihydroxycholecalciferol in rat tissues.

Vitamin D metabolites stimulate creatine kinase BB activity in organs of vitamin D-deficient rats. In epiphyses of long bones, creatine kinase BB activity increases 2.6-fold 24 h after injection of 24R,25-dihydroxycholecalciferol but not of 1 alpha,25-dihydroxycholecalciferol. Contrariwise, 1 alpha,25-dihydroxycholecalciferol, but not 24R,25-dihydroxycholecalciferol, increases creatine kinase BB activity in diaphyses and in kidney. Neither metabolite affects creatine kinase activity in duodenal mucosa.

24,25-Dihydroxyvitamin D 3↗
PubMed1984

24R,25-dihydroxyvitamin D stimulates creatine kinase BB activity in chick cartilage cells in culture.

In chick limb-bud cartilage cell cultures 24R,25-dihydroxycholecalciferol (24R,25(OH)2D3), but not 24S,25(OH)2D3, 1 alpha,25(OH)2D3 or 25(OH)D3, stimulates the activity of the brain type (BB) isozyme of creatine kinase (EC 2.7.3.2), the 'estrogen-induced protein' first identified in rat uterus. Cultures treated with bromodeoxyuridine, in which cartilage formation is inhibited, show no stimulation of creatine kinase BB by 24R,25(OH)2D3.

24,25-Dihydroxyvitamin D 3↗
PubMed1984

Creatine kinase BB in normal, hyperplastic and neoplastic endometrium.

We measured creatine kinase BB activity in normal, hyperplastic and neoplastic endometrium. Creatine kinase BB levels were higher in secretory than in proliferative endometrium. High levels were also found in hyperplastic tissue. In endometrial cancer creatine kinase BB activity was higher in well differentiated than in poorly differentiated tumors.

Creatine Kinase↗
PubMed1984

Estrogen-responsive creatine-kinase in the reticulo-epithelial cells of rat thymus.

We have evaluated the presence of the so-called "estrogen-induced protein" (IP) in the thymus of immature rat. IP is one of the earliest proteins synthesized in response to estrogen in rat uterus and has recently been identified as the BB-isozyme of creatine-kinase (J. Biol. Chem. 256 (1981) 5741). Estrogen-exposed tissues were labelled with [35S]methionine and the soluble proteins separated by SDS-polyacrylamide gel electrophoresis followed by fluorography. It was observed that estrogen stimulated the labelling of a thymic protein with electrophoretic mobility identical to that of uterine IP. The effect was dose-related and specific for estrogen receptor ligands. Thymic IP, like that of the uterus, was immunoprecipitated equally well by either anti-IP antiserum from rat uterus or anti-BB-creatine-kinase antiserum from rat brain. After purification by ion-exchange and affinity chromatography, there was a parallel increase in the extent of recovery of IP and BB-creatine-kinase activity in both the thymus and the uterus. Using the immunohistochemical peroxidase-antiperoxidase method with anti-IP serum, the immune-reaction product was localized in a few cells identified as reticulo-epithelial cells. The thymocytes were always free of any reaction product. These data demonstrate that the reticulo-epithelial cells of rat thymus are a target for estrogens.

Animals↗