Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Localized juvenile periodontitis (ljp) is an early onset form of periodontal disease characterized by unique localization to first molars and incisors and a high prevalence of neutrophil abnormalities, particularly chemotaxis. The intracellular transduction mechanisms that follow receptor-ligand coupling on the neutrophil surface and lead to chemotaxis are not clearly established. Chemotaxis and phagocytosis are modulated by a variety of receptors and involve several activation pathways; the role of intracellular calcium as a presumptive second messenger and mediator of these events is well established. The putative effector mechanisms for the chemotactic receptor of neutrophils also include the possible activation of a phospholipase, protein kinase C, methyltransferase, or adenylate cyclase. In normal neutrophils, a phosphoinositide pathway initiated by phospholipase C, which results in the activation of protein kinase C via diacylglycerol and the generation of IP3, has been implicated. In order to better understand the stages of neutrophil transduction, fluorescent probes were used to monitor neutrophil calcium changes. Chlorotetracycline (CTC) was used as an indirect probe of intracellular membrane-bound pool of calcium stores, and Quin-2 was used to monitor cytosolic free calcium levels of FMLP stimulated normal and LJP neutrophils. The results indicate that the early phase of the calcium response affiliated with the release of intracellularly sequestered calcium appears intact in LJP neutrophils, as the CTC fluorescence changes were similar to control values. The second phase of the calcium response, associated with membrane channel activation and an influx of extracellular calcium, appeared compromised in the neutrophils of the LJP population.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Defective chemotaxis and calcium response in localized juvenile periodontitis neutrophils. 839 75

Fertilization promoting peptide (FPP) and adenosine were demonstrated to be potential modulators of sperm capacitation in mammals. Both FPP and adenosine, by modulating the adenylate cyclase (AC)/cAMP signaling pathway, elicit similar biphasic responses in mammalian sperm (i.e., stimulating capacitation and inhibiting spontaneous acrosome loss). Pentoxifylline, an artificial sperm stimulant, is clinically used to enhance motility of sperm from infertile men. By inhibiting phosphodiesterase, pentoxifylline increases the intracellular cAMP level of sperm, and thus contributes to capacitation, hyperactivation, and acrosome reaction in animal studies. The effects of FPP, adenosine, and pentoxifylline on thawed human sperm are stressed. Chlortetracycline (CTC) fluorescence assessment revealed that none of the 3 reagents improved fertilization ability of post-thawed sperm. Motility studies with computer-aided sperm analyzer (CASA) showed significantly smaller STR (straight-line velocity) and LIN (linearity) in the FPP-treated group at 4 h of incubation p<or=005, significantly larger VCL in the adenosine-treated group p<or=.05, and significantly larger VCL (curvilinear velocity) and smaller LIN in the pentoxifylline-treated group p<or=.05. Significant decreases in percentage motility were also noted in both FPP and adenosine-treated groups p<or=05. It would appear that FPP potentiates fertilizing ability and prevents spontaneous acrosome loss, via regulating membrane-bound Na(+)-K(+) ATPase, and/or Ca(2+) ATPase, by keeping the sperm intracellular Ca(2+) concentration within the physiological range optimal for fertilization. adenosinefertilizationFPPpentoxifyllinespermthawing
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PMID:Effects of fertilization promoting peptide, adenosine, and pentoxifylline on thawed human sperm. 1262 51