calcimycin and 2-aminoethoxydiphenyl-borate

Endothelial and smooth muscle Transient Receptor Potential (TRP) channels contribute to regulation of vascular tone. We have previously reported sex differences in the endothelial function in porcine isolated coronary arteries (PCAs). The present study examined the role of TRP channels in endothelium-dependent and H2O2-induced vasorelaxations in male and female PCAs. Distal PCAs were mounted in a wire myograph and precontracted with U46619. Concentration-response curves to bradykinin, H2O2 and A23187 were constructed in the presence of TRP channel antagonists with or without L-NAME and indomethacin to inhibit NO synthase and cyclooxygenase respectively. 2-APB (TRPC & TRPM antagonist) inhibited the maximum relaxation (Rmax) of the bradykinin-induced vasorelaxation and abolished the EDH-type response in PCAs from both sexes. SKF96365 (TRPC antagonist) inhibited the Rmax of bradykinin-induced vasorelaxation in males, and inhibited Rmax of the EDH-type response in both sexes. Pyr3 (TRPC3 antagonist) inhibited both the NO and EDH components of the bradykinin-induced vasorelaxation in males, but not females. RN1734 (TRPV4 antagonist) reduced the potency of the NO component of the bradykinin-induced vasorelaxation in females only, but inhibited the Rmax of the EDH-type component in both sexes. 2-APB, SKF96365 and RN1734 all reduced the H2O2-induced vasorelaxation, whereas Pyr3 had no effect. No differences in expression level of TRPC3 and TRPV4 between sexes were detected using Western blot. Present study demonstrated a clear sex differences in the role TRP channels where TRPC3 play a role in the NO- and EDH-type response in males and TRPV4 play a role in the NO-mediated response in females.

Topics: Animals; Boron Compounds; Bradykinin; Calcimycin; Coronary Vessels; Endothelium, Vascular; Female; Gene Expression Regulation; Hydrogen Peroxide; Imidazoles; Indomethacin; Male; NG-Nitroarginine Methyl Ester; Pyrazoles; Sex Characteristics; Sulfonamides; Swine; Transient Receptor Potential Channels; Vasodilation

During the early blastula period of zebrafish embryos, the outermost blastomeres begin to undergo a significant thinning in the apical/basolateral dimension to form the first distinct cellular domain of the embryo, the enveloping layer (EVL). During this shape transformation, only the EVL-precursor cells generate a coincidental series of highly restricted Ca(2+) transients. To investigate the role of these localized Ca(2+) transients in this shape-change process, embryos were treated with a Ca(2+) chelator (5,5'-difluoro BAPTA AM; DFB), or the Ca(2+) ionophore (A23187), to downregulate and upregulate the transients, respectively, while the shape-change of the forming EVL cells was measured. DFB was shown to significantly slow, and A23187 to significantly facilitate the shape change of the forming EVL cells. In addition, to investigate the possible involvement of the phosphoinositide and Wnt/Ca(2+) signaling pathways in the Ca(2+) transient generation and/or shape-change processes, embryos were treated with antagonists (thapsigargin, 2-APB and U73122) or an agonist (Wnt-5A) of these pathways. Wnt-5A upregulated the EVL-restricted Ca(2+) transients and facilitated the change in shape of the EVL cells, while 2-APB downregulated the Ca(2+) transients and significantly slowed the cell shape-change process. Furthermore, thapsigargin and U73122 also both inhibited the EVL cell shape-change. We hypothesize, therefore, that the highly localized and coincidental Ca(2+) transients play a necessary role in initiating the shape-change of the EVL cells.

Topics: Animals; Blastomeres; Blastula; Boron Compounds; Calcimycin; Calcium Compounds; Calcium Signaling; Cell Shape; Chelating Agents; Egtazic Acid; Estrenes; Fluorescence; Microscopy, Confocal; Pyrrolidinones; Thapsigargin; Wnt Proteins; Wnt-5a Protein; Zebrafish; Zebrafish Proteins