Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activity of tissue and blood plasma kallikreins as well as total content of their inactive precursors were studied in rabbit eye structures and media: iris, ciliary body, cornea, vascular striatum, retina, aqueous humor, tear liquid, lacrimal gland by means of fluorimetric procedure using Z-Phe-Arg-MCA as a substrate. Dissimilar capacity of the trypsin soya bean inhibitor and of aprotinin (basic inhibitor of Kunitz type) to inhibit tissue and blood plasma kallikreins enabled to differentiate the enzymatic activity. Lacrimal gland contained the highest activity of tissue kallikrein which amounted to 70% of total Z-Phe-Arg-MCA-hydrolyzing activity of the homogenate. Total Z-Phe-Arg-MCA-amidase activity and activity of individual kallikreins was distinctly lower in all the eye structures and media studied as compared with that of lacrimal gland. Activity of tissue kallikrein was higher than blood serum kallikrein activity in iris, ciliary body, vascular striatum, retina and conjunctiva. The highest content of prekallikreins was found in conjunctiva, aqueous humor, iris and ciliary body. Tissue and blood plasma kallikrein-kinin systems appear to carry out dissimilar functions in eye tissue structures; they are apparently involved in pathogenesis of some eye diseases.
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PMID:[Activity of tissue and plasma kallikrein and level of their precursors in eye tissue structures and media of healthy rabbits]. 172 76

While on therapy for acute myeloid leukemia, a 15-year-old girl developed extensive punctate keratitis of both eyes following high-dose cytarabine therapy (HD-Ara-C). Pharmacokinetic monitoring showed an increase of the Ara-C plasma levels up to twice the steady-state level within 10 minutes after discontinuation of the Ara-C infusion. Calculations of Ara-C plasma half-life, plasma clearance and volume of distribution were within the expected range. Owing to the short half-life of Ara-C in blood due to rapid deamination, varying infusion velocities will result in markedly varying plasma levels. Higher peak plasma levels lead to proportionally higher diffusion into compartments like tears, aqueous humor and cerebrospinal fluid. In compartments which lack noteworthy deaminase activity, dose intensity will be much more enhanced than in plasma. Peak plasma levels, therefore, may be associated with multifold local toxicity without concurrent increase of hematological toxicity. Especially when the drug is given in small volumes of infusion, these considerations should be taken into account. Precise control of infusion parameters and application of artificial tears for dilution of the Ara-C concentration on the corneal surface should be part of keratitis prophylaxis.
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PMID:Is there a relationship between cytarabine pharmacokinetics and keratitis?--A case report. 831 60