Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bradykinin gave a biphasic increase in intracellular free Ca2+ concentration ([Ca2+]i) in serum-deprived Swiss 3T3 fibroblasts loaded with the photoprotein aequorin. Epidermal growth factor (EGF) alone did not increase [Ca2+]i, but when added after bradykinin there was an increase in [Ca2+]i. The EGF-dependent increase in [Ca2+]i was maximal at 3 min and disappeared with a half-life of 6 min after bradykinin. Removing Ca2+ from the external medium did not abolish either the bradykinin or the EGF-induced [Ca2+]i responses. Although prostaglandins E2 and F2 alpha also gave [Ca2+]i responses and permitted an EGF-dependent [Ca2+]i response, the effect of bradykinin did not appear to be mediated by prostaglandins since it was not blocked by indomethacin. Vasopressin and phorbol 12-myristate 13-acetate both gave a [Ca2+]i response but did not facilitate a [Ca2+]i response by EGF. Bradykinin or EGF alone did not increase DNA synthesis in growth-arrested Swiss 3T3 fibroblasts, but EGF added together with, or after, bradykinin increased DNA synthesis. The effect disappeared with a half-life of 180 min after the addition of bradykinin. It is concluded that stimulation of receptor protein tyrosine kinase is unlikely, by itself, to explain the increase in DNA synthesis produced by EGF. The observed increase in [Ca2+]i caused by EGF after bradykinin probably reflects the interaction of intracellular second messenger pathways leading to facilitation of DNA synthesis.
...
PMID:An increase in intracellular free Ca2+ associated with serum-free growth stimulation of Swiss 3T3 fibroblasts by epidermal growth factor in the presence of bradykinin. 326 65

The C-terminal eight-amino acid derivative of CCK, sulfated on the tyrosine residue (CCK8S), stimulated a dose-dependent biphasic pattern of insulin secretion from isolated perifused islets in the presence of 7 mM glucose. It was without any effect if glucose were absent from the medium or maintained at 4 mM. The response to CCK8S was readily reversible and dependent on the presence of extracellular calcium. While CCK8S did not increase glucose usage rates above those noted with 7 mM glucose alone, inclusion of the metabolic inhibitor 2-deoxyglucose lowered glucose usage rates to values obtained with 3-5 mM glucose and abolished the influence of CCK8S on insulin output. Removal of the metabolic inhibitor restored the secretory response. N-Acetylglucosamine (15 mM) or glyceraldehyde (2.5 mM) substituted for glucose and permitted CCK8S to evoke secretion. The nonsulfated eight-amino acid derivative of CCK, CCK8, provoked insulin secretion in the presence of 7 mM glucose, but only at 10-100 times greater levels than CCK8S. CCK4 (1 microM) did not influence insulin output in the presence of 7 mM glucose. On an equimolar basis, CCK8S was significantly more effective than gastric inhibiting polypeptide in augmenting insulin output. The results support a role for CCK8S in the regulation of insulin levels in vivo.
...
PMID:Influence of cholecystokinin on insulin output from isolated perifused pancreatic islets. 352 23

From the pre-natal follow-up it was remarkable that cases have been admitted relatively late. Hints to a possible development of preeclampsia could be seen from patients history or the routine check up, for example the registration of edema, fetal growth retardation and oligohydramnios. For early diagnosis of preeclampsia we recommend: Calculation of mean arterial blood pressure or its non-invasive measurement; determination of hematocrit, uric acid and total plasma protein (in particular hemorheologic measurements). Hypomagnesemia in preeclampsia, as described by some authors, was also seen in our cases. The complex symptomatology of preeclampsia could be attributed to a generalised disturbance of microcirculation, which leads to definite reactions of the organs concerned. The microcirculatory failure is caused by vasoconstriction, hemoconcentration, hyperviscosity and hypercoagulation (up to DIC and consumption coagulopathy). The resulting symptoms and syndromes can be: EPH, HELLP, hemolytic-uremic Syndrome, hepato-renal Syndrome, thrombocyte and antithrombin III deficiency etc. The drug of choice for treatment of preeclampsia is magnesium sulfate. Its application is based on long-term clinical experience and new aspects on the physiologic and pharmacologic role of magnesium. The recommendations of the German High Blood Pressure League to use calcium antagonists as a basis in the treatment of high blood pressure can be fulfilled particularly in pregnancy by the physiologic calcium antagonist Mg++. Magnesium sulfate should be given in a dosage of 24-72 g daily. The dose should also be made dependent from urinary output. Further treatment patterns of preeclampsia should be adjusted according to each case. The present results also support our hypothesis that magnesium deficiency (besides predisposing factors) could be responsible for the development of preeclampsia (present model shown in detail). Consequently, the early and long-term substitution of magnesium in pregnancy could help reduce preeclampsia.
...
PMID:[Pathophysiology and clinical aspects of pre-eclampsia]. 404 84

Various agents which are known to affect intracellular levels of cAMP have been assessed for their ability to induce the release of [3H]acetylcholine ([3H]ACH) from a synaptosomal preparation derived from the guinea-pig ileum myenteric plexus. 8-Bromo-cAMP increased the release of [3H]ACh above basal levels. While 8-bromo-cGMP also increased the release, this nucleotide was far less potent than 8-bromo-cAMP. Comparison of the release caused by the cyclic nucleotides to the release induced by the nicotinic agonist dimethylphenylpiperazinium (DMPP) suggested that there is some relationship, as yet undefined, between the 8-bromo-cAMP-induced and the DMPP-induced release, while no relationship was evident between the release induced by 8-bromo-cGMP and that caused by DMPP. The 8-bromo-cAMP-induced release was Ca2+-dependent. Neither adenosine, clonidine, nor oxotremorine (all of which modulate the nicotinically-induced release) affected the 8-bromo-cAMP-induced release. The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine stimulated the release of [3H]ACh as did the adenylate cyclase activator forskolin. The forskolin-induced release was not affected by adenosine, clonidine or oxotremorine. The ability of the modulators to block the nicotinically-induced release but not the release caused by the cyclic nucleotides indicates that the modulation of release evoked by nicotinic activity does not occur at a step involving protein phosphorylation.
...
PMID:Stimulation of acetylcholine release from guinea-pig ileal synaptosomes by cyclic nucleotides and forskolin. 620 34

Action of pentobarbitone was studied on isolated segments of the terminal and middle ileum of the guinea-pig and compared with the effects of verapamil. Pentobarbitone (10(-4)-10(-3) M) was found to almost equally inhibit responses produced by ES at 3 Hz and ACH, and those elicited by ES at 30 Hz and NA. Increase in the extracellular calcium did not antagonize the effects of pentobarbitone on both types of ES. These results are an indication of a postsynaptic site of action. The concentration-response curves to calcium-induced contractions (3-300 microM) were displaced to the right by both drugs; however, unlike verapamil, pentobarbitone markedly reduced the maximum response to calcium. Calcium-induced contractions after reaching the plateau level were relaxed both by pentobarbitone and verapamil. Pentobarbitone lowered the resting tone even in the high-KCl depolarizing solution, while verapamil produced no change in this series of experiments. It could be concluded that pentobarbitone when used in anesthetic concentrations might affect contractility of the intestinal smooth muscle by an action located at the postsynaptic membrane or beyond it. The antagonism between pentobarbitone and calcium appeared to be noncompetitive and is presumed to be effected via an indirect action on the functioning of calcium channels.
...
PMID:Calcium antagonistic action of pentobarbitone on the isolated terminal ileum of the guinea-pig. 632 Jul 52

In man, the influence of calcium entry blockers (CEB) on nonspecific bronchial sensitivity and resting bronchial tone is controversial. In 10 asthmatic and 8 normal subjects we recorded specific airway conductance (Gaw/VL) and flow volume loops before, 30, 60, and 90 min after the inhalation of saline, 10 (V10) and 20 mg (V20) of verapamil. The dose of inhaled histamine and acetylcholine producing Gaw/VL of -40% (PD40H and PD40ACH, respectively) with and without pretreatment with saline, V10, and, in 15 subjects, V20 was also determined. We measured plasma verapamil concentrations immediately after the end of nebulization of V10 and V20, and 30 and 60 min later. In normal subjects, V10 and V20 produced a maximal % delta Gaw/VL of 22.30 (+/- 19.50) and 33.00 (+/- 15.82), respectively (p less than 0.05). In asthmatics, V10 and V20 produced comparable % delta Gaw/VL of 22.00 (+/- 22.50) and 38.60 (+/- 38.60), respectively. This bronchodilating effect involved predominantly the large airways, persisted for 60 to 90 min, was reproducible, affected only some subjects (11 of 18), and was independent of the resting Gaw/VL, degree of bronchial sensitivity to H and ACH, and the time course of plasma verapamil concentration. The latter reached a maximum of 24.3 +/- 7.1 ng/ml after V20. In both normal and asthmatic subjects, saline or V10 did not significantly alter PD40H and PD40ACH. In normal subjects, pretreatment with V20 increased PD40H 5.3 times and PD40ACH 3.22 times (p less than 0.05). Except in 2 asthmatics, in whom V20 decreased PD40 and PD40ACH, it increased significantly PD40ACH (dose ratio: 3.15, p less than 0.05) but not PD40H.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The effect of inhaled verapamil on resting bronchial tone and airway contractions induced by histamine and acetylcholine in normal and asthmatic subjects. 650 96

Preischaemic doubling of the myocardial buffer capacity optimizes the energy supply of the ischaemic heart by anaerobic glycolysis. For osmotic reasons this method of improving ischaemia tolerance can only be realized in combination with cardioplegia by extracellular Na+ and Ca2+ reduction. The cardioplegic solution 'HTK' which has been developed according to these considerations. (1) delays the decay velocity of myocardial ATP by a factor of 7-8 in comparison with pure ischaemia; (2) leads to a good myocardial recovery with regard to metabolic, morphological, and functional criteria after an ischaemic stress of 300 min at 23 +/- 1 degrees C--especially after the addition of quinine; (3) is considerably reduced in its protective efficacy by adding 50 mumol l-1 Ca2+; (4) causes a calcium paradox if it is infused for 30 min at 35 degrees C; this does not happen if it is infused for 60 min at 25 degrees C or for 120 min at 15 degrees C; on adding 50 mumol l-1 Ca2+ to the solution the risk of a calcium paradox is significantly reduced, even after infusion for 35 min at 35 degrees C; (5) effects an evident delay of recovery, if a continuous ischaemic stress of 300 min at 23 degrees +/- 1 degree C is reduced to 3 X 100 min of ischaemia at 17 +/- 1 degrees C by intermittent cardioplegic reperfusion; (6) considerably improves the myocardial recovery even after intermittent cardioplegia if 50 mumol l-1 Ca2+ are added or Mg2+ is reduced from 9 to 4 mmol l-12. The metabolic, morphological, and functional results are equivalent to those after 300 min of continuous ischaemia. Further investigations must show to what extent the 'membrane stabilizing effect' of [Ca2+]o can be achieved by taking advantage of mutual ionic interaction on the level of plasmalemma (e.g. H+-Mg2+-Ca2+) or by adding membrane effective substances (quinine).
...
PMID:Calcium-free cardioplegia--pro. 666 28

In oxidative phosphorylation and ATP-driven uphill electron transfer from succinate to NAD, double-reciprocal plots of rates vs. substrate concentrations of the energy-driven reactions are a family of parallel lines at several fixed subsaturating concentrations of the substrates or at several moderate concentrations of the inhibitors of the energy-yielding reactions. Thus, as shown elsewhere [Hatefi, Y., Yagi, T., Phelps, D. C., Wong, S.-Y., Vik, S. B., & Galante, Y. M. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 1756-1760], partial uncoupling decreases the Vappmax and increases the Kappm of the substrates of the energy-driven reactions, resulting in a decrease of Vmax/Km as a function of increased uncoupling. However, partial limitation of the flow rates of the energy-yielding reactions decreases both the Vappmax and the Kappm of the substrates of the energy-driven reactions, resulting in no change in Vmax/Km. This is true as long as the rate limitation is moderate (e.g., less than 60%), under which conditions the steady-state membrane potential (delta psi) remains essentially unchanged. At high inhibition of the energy-yielding reactions, or at moderate inhibition in the presence of low levels of an uncoupler to cause partial uncoupling, then the family of double-reciprocal plots is no longer parallel and tends to converge toward the left. Under these conditions, steady-state delta psi and Vmax/Km also decrease as inhibition is increased. The relationship between the magnitude of steady-state delta psi and the rate of the energy-driven reaction was studied in oxidative phosphorylation, ATP-driven electron transfer from succinate to NAD, and respiration-driven uniport calcium transport by intact mitochondria.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Modulation of the kinetics and the steady-state level of intermediates of mitochondrial coupled reactions by inhibitors and uncouplers. 671 22

Using the thymidine kinase gene-containing plasmid pTK-1 and the mouse fibroblast thymidine kinase-deficient LTK- cell line, we obtained results indicating that the plasmid molecules suspended in the external medium were introduced into the nuclei by pricking cells on the nuclei with a microneedle. Approx. 25% of the cells pricked in the presence of the plasmid pTK-1 showed TK gene expression, and 2% of the cells became stable TK+ transformants. This 'pricking' method is applicable for introducing DNA into cell nuclei and is more efficient than the conventional calcium phosphate transformation method.
...
PMID:The 'pricking' method. A new efficient technique for mechanically introducing foreign DNA into the nuclei of culture cells. 695 71

Adipocytic-cytosolic non-receptor protein tyrosine kinase (CytPTK) when activated can substitute for the insulin receptor tyrosine kinase (InsRTK), in manifesting several insulin effects in insulin-receptor independent fashion. Our aims here were to utilize PolyGlu4Tyr, a good experimental exogenous substrate for protein tyrosine kinases (PTKs) in general, for studying qualitative and quantitative parameters of CytPTKs extracted from different tissue cytosols. At the same time, we would search for a unique specific marker specifically characterizing CytPTKs. High speed supernatants of spleen, thymus, smooth muscle, lung and kidney were found to be rich in CytPTK activities. Their specific activities being 6- to 13-fold that of liver or adipose cytosols. Brain, testis and adrenal cytosols were an intermediate source of CytPTK activity, whereas CytPTK activity of heart and skeletal muscle was low. It was also evaluated that the capacity of the cytosol to phosphorylate PolyGlu4Tyr is 15-50% that of the non-stimulated Triton X-100 extractable plasma membrane PTKs. Fractionation of the cytosols on superose 12 column revealed several CytPTKs within the same tissue, their peaks ranging between 30 and 450 kDa. Immunoblotting analysis showed Fyn and Lyn were present in most tissue cytosols. Upon immunoprecipitation, however, with anti-Fyn or anti-Lyn, negligible amounts (< 2%) of the total cellular CytPTK were precipitated. Thus, these general markers of CytPTKs comprise only a minor proportion of the total intracellular PolyGlu4Tyr phosphorylating capacity. To see whether a specific marker for CytPTK could be detected, we also examined the requirement of CytPTKs for divalent ions, their preferred phosphate donor and their sensitivity to inhibition by known PTK inhibitors. We found that the order of reactivity with divalent cations was Co2+ > Mn2+ > Mg2+, while Zn2+ and Ca2+ did not support CytPTK activity. The best phosphate donor was ATP (ED50 = 5 microM), but other nucleoside 3-phosphates could substitute for ATP at high concentrations. With respect to these parameters, no basic difference exists between cytosolic and plasma-membrane PTKs. The PTK inhibitors, genestein and quercetin, inhibited both cytosolic and membranal PTKs at micromolar concentrations. In contrast, staurosporine was a potent inhibitor of CytPTKs (IC50 5-20 nM) and a poor inhibitor of membranal PTKs (IC50 10-40 microM). One of the conclusions we can draw from this study is that tissue cytosols contain PolyGlu4Tyr phosphorylating capacity in quantities greater than previously assumed and that the low level of phosphotyrosine found in cells is not the result of limited intracellular levels of CytPTKs.
...
PMID:Non-receptor cytosolic protein tyrosine kinases from various rat tissues. 749 84


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---