Inhibitory effect of the CA2+ antagonist nifedipine on histamine release from rat peritoneal mast cells.

45Ca uptake and histamine release was examined in mast cells from rats sensitized with ovalbumin and Bordetella Bertussis as an adjuvant. The uptake of 45Ca by the mast cells was significantly increased by stimulation with ovalbumin as was the release of histamine from the mast cells. Nifedipine, a calcium antagonist, inhibited the increase in both 45Ca uptake and histamine release stimulated by ovalbumin, though the effect on 45Ca uptake was stronger than that on histamine release.</p

EST analysis of genes that are expressed in the neural complex of Ciona intestinalis adults.

A subtractive cDNA library was made corresponding to mRNAs expressed in the neural complex relative to those expressed in the pharynx of adults of the ascidian Ciona intestinalis. Determination and comparison of expressed sequence tags (ESTs) of a set of 1,527 randomly selected clones demonstrated that they represent 832 independent sequences. Five hundred seventy-two of the clones contained amino-acid-encoding sequences. BLASTX analyses showed that 342 of the 572 clones were strong matches (P<10(-7)) to previously identified proteins, while the remaining 230 fell into the "no match" category. Among the clones matching previously identified proteins, about 80 clones represented proteins that are involved in the formation, maintenance of the structure, and function of the nervous system: 22 proteins are associated with signal transduction, five proteins are related to the synapse, 11 to transcription factors, nine to transporters, five to enzymes, and 13 to extracellular matrix and cytoskeletal components, and six to apoptosis. In addition, sequence information for genes associated with the immune system and for genes encoding proteins with interesting functions were obtained. These data provide cues for further studies on genes that are expressed in and function in the ascidian nervous system

Inhibitory effect of Ca(2+) antagonist on (45)Ca uptake by mast cells

(45)Ca uptake by rat peritoneal mast cells was observed, and the inhibitory effect of nifedipine, a Ca(2+) antagonist, on (45)Ca uptake by mast cells, stimulated by an antigen, comp. 48/80, concanavalin A and Ca ionophore A 23187, was examined. The increase in (45)Ca uptake by mast cells induced by the antigen paralleled the increase in mast cell number. A significant increase in the uptake of (45)Ca by mast cells was observed with the stimulation by the antigen, comp. 48/80, concanavalin A and Ca ionophore A 23187. The increased uptake of (45)Ca induced by antigen was inhibited by nifedipine, and this dose-dependent inhibitory effect of nifedipine on (45)Ca uptake was also observed in the mast cells stimulated by comp. 48/80, concanavalin A and Ca ionophore A 23187