Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat pancreatic acini were prepared with collagenase A and collagenase P and their secretory response to carbachol tested. The collagenase P gave the best acinar suspension, providing that the digestion was performed in the absence of added calcium and in the presence of a low concentration of albumin. More than ninety percent of the acini prepared with this crude collagenase were viable as judged by a coloration with eosine. Their basal amylase secretion was below 3% amylase released within 20 minutes. They responded to cholecystokinin (7-fold stimulation, EC50: 10 pM), to bombesin (7-fold stimulation, EC50: 1 nM), to carbachol (7-fold stimulation, EC50: 1 microM), to fluoroaluminate (4-fold stimulation, EC50: 3 mM) or to TPA (4-fold stimulation, EC50: 100 nM). Acini preloaded with fura2 and incubated in the presence of 0.5 mM extracellular calcium were able to maintain a large (5,000-fold) gradient of calcium across their plasma membrane. Carbachol, CCK-8 and bombesin increased the intracellular calcium concentration 6-fold, within 10 seconds. This level decreased for the next 20 seconds but remained higher than the basal value for the next 10 minutes. These acini could be permeabilized with a low concentration (0.1 U/ml) of streptolysin O without affecting the basal amylase secretion, an index of the integrity of zymogen granules. It is concluded that pancreatic acini which have retained their responsiveness to major pancreatic secretagogues can be prepared with crude collagenase and permeabilized with streptolysin O. They can thus be used as a model for the study of stimulus-secretion coupling in exocrine glands.
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PMID:Isolation of rat pancreatic acini with crude collagenase and permeabilization of these acini with streptolysin O. 767 14

Single adult cardiac ventricular cells were prepared by collagenase perfusion of a rat heart. They were stimulated electrically in a perfusion chamber and their length changes were followed under a microscope. The motion was followed via a video camera and by a TV-line counting device and was recorded on-line by a personal computer. The program RECORD was used to calculate peak amplitude, base line drift and peak width at different peak heights allowing the determination of a number of variables of the cellular motion. The method was applied to drugs affecting the amplitude of contractions and the speed of relaxation. Results of beta-adrenergic stimulation, muscarinic inhibition and of the Ca(2+)-ATPase inhibitor cyclopiazonic acid (CPA) are shown. Besides its stimulatory effect on length, the beta-adrenergic agonist isoprenaline concentration-dependently shortened relaxation time. Carbachol reversed the increase in cellular shortening caused by isoprenaline in a concentration-dependent manner without fully reversing the shortened relaxation. CPA prolonged the return to diastole, presumably due to its inhibition of Ca(2+)-reuptake into the sarcoplasmatic reticulum.
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PMID:A computer program for motion analysis of single cardiac myocytes. 845 Apr 90

Carbachol-mediated activation of type M(3) muscarinic acetylcholine receptors induces the biosynthesis of the transcription factor Egr-1 in human SH-SY5Y neuroblastoma cells involving an activation of extracellular signal-regulated protein kinase. Carbachol triggered the phosphorylation of the ternary complex factor Elk-1, a key transcriptional regulator of serum response element-driven gene transcription, and strikingly enhanced the transcriptional activation potential of Elk-1. Chromatin immunoprecipitation experiments revealed that Elk-1 binds in vivo to the 5'-upstream region of the Egr-1 gene in carbachol-stimulated neuroblastoma cells. Together, these data indicate that Elk-1 connects the intracellular signaling cascade elicited by activation of M(3) muscarinic acetylcholine receptors with the transcription of the Egr-1 gene. Lentiviral-mediated expression of either MAP kinase phosphatase-1 (MKP-1) or a constitutively active mutant of calcineurin A inhibited Egr-1 biosynthesis following carbachol stimulation, indicating that these phosphatases function as shut-off devices of muscarinic acetylcholine receptor signaling. Additionally, carbachol stimulation increased transcription of a chromatin-embedded collagenase promoter/reporter gene, showing that AP-1 activity is enhanced in carbachol-stimulated neuroblastoma. Expression experiments revealed that both MKP-1 and a constitutively active mutant of calcineurin A impaired carbachol-induced upregulation of AP-1 activity. The fact that carbachol stimulation of neuroblastoma cells activates the transcription factors Egr-1 and AP-1 suggests that changes in the gene expression pattern are an integral part of muscarinic acetylcholine receptor signaling.
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PMID:Transcriptional response to muscarinic acetylcholine receptor stimulation: regulation of Egr-1 biosynthesis by ERK, Elk-1, MKP-1, and calcineurin in carbachol-stimulated human neuroblastoma cells. 1806 71


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