Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.2 (guanylate cyclase)
 8,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies have demonstrated that nitroso chemical carcinogens activate guanylate cyclase (EC 4.6.1.2) which catalyzes the production of guanosine 3',5'-monophosphate. This nucleotide is thought to be involved in normal and abnormal cell growth. We examined the effect of 3 major classes of anticancer chemotherapeutic agents, the antimetabolites (methotrexate and 6-mercaptopurine), antitumor antibiotics (adriamycin and actinomycin D), and alkylating agents (cytoxan, uracil mustard, isophosphamide, chlornaphazine, and 1-propranol-3,3'-iminodimethane sulfonate) on the activation of guanylate cyclase by nitroso chemical carcinogens. The anticancer chemotherapeutic agents noncompetitively blocked the activation of rat hepatic guanylate cyclase by N'-nitro-N-nitroso-N-propylguanidine (NNPG) and hydrazine. Adriamycin, methotrexate, and uracil mustard were the most effective inhibitors completely abolishing the effect of 1 mM NNPG on guanylate cyclase activity. The remainder of the anticancer chemotherapeutic agents abolished the NNPG activation of guanylate cyclase 40--70%. Since a previously described guanylate cyclase inhibitor has been shown to terminate the growth of an undifferentiated prostatic cancer in tissue culture the present data may indicate that one of the mechanisms by which anticancer chemotherapeutic agents exert their effects is by inhibition of tumor guanylate cyclase activity.
 ...
PMID:Inhibition of nitroso chemical carcinogen activation of rat hepatic guanylate cyclase by anticancer agents. 3 20

This study was undertaken to find out the mechanism of non-agglutinable Vibrio cholerae heat-stable enterotoxin (NAG-ST)-induced calcium influx across the plasma membrane. Adriamycin, an inhibitor of IP3-specific 3-kinase, could not inhibit NAG-ST-induced calcium influx in rat intestinal epithelial cells, which suggested that inositol 1,3,4,5-tetrakisphosphate (IP4) had no role in NAG-ST-induced calcium influx. NAG-ST increased intracellular nitric oxide level of rat enterocytes as measured by a fluorimetric method using a fluoroprobe 4,5-diaminofluorescein-2-diacetate (DAF-2DA). N-Nitro-L-arginine, an inhibitor of nitric oxide synthase, inhibited NAG-ST-induced rise in nitric oxide level and also calcium influx. Inhibition of inositol trisphosphate (IP3)-mediated intracellular calcium mobilization by Dantrolene could also inhibit NAG-ST-induced rise in intracellular nitric oxide level. Moreover, inhibition of soluble guanylate cyclase by inhibitors (ODQ, LY83583) could inhibit the NAG-ST-induced rise in cyclic guanosine-3',5'-monophosphate (cGMP) level and calcium influx. From this study, it is evident that NAG-ST causes IP3-mediated calcium release from intracellular calcium store, which then stimulates nitric oxide production by activating nitric oxide synthase and the nitric oxide through cGMP activates calcium influx.
 ...
PMID:Role of nitric oxide in NAG-ST induced store-operated calcium entry in rat intestinal epithelial cells. 1529 24