title: The physiology of infection with nematodes: the role of intracellular pH in the development of the early parasitic stage.
abstract: 1. H2CO3, the host's signal which induced (less than 25 min) the Ca2+-dependent development of the first parasitic stage of Haemonchus contortus, produced a diphasic change in the pHi (less than 30 min), measured with 5,5-dimethyl-2,4-oxazolidinedione, in the infective stage. The intensity of the diphasic change was related to the [H2CO3] and so to the efficiency of the stimulus for development. 2. MES and HEPES buffers induced a rapid rise in pHi of infective stages in step with pHo. Ortho-and pyrophosphate induced greater changes in pHi. Such buffers did not initiate development. 3. These and other results suggest that the stimulus for development, H2CO3, induced an energy-dependent Ca2+/H+ exchange mediated by mitochondria of the infective stage, which initiated development of the parasitic stage.
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002255:Carbonic Acid / Q000502:physiology; D006189:Haemonchus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009348:Nematoda / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D009349:Nematode Infections / Q000469:parasitology; D010710:Phosphates / Q000494:pharmacology
chemical_list: D010710:Phosphates; D000643:Ammonium Chloride; D002255:Carbonic Acid