title: Sugar reception in the blowfly: a possible Ca(++) involvement.
abstract: The present study investigates the effects of W-7 (a calmodulin antagonist involved in the Ca(++) cascade) on the response of the 'sugar' and 'water' cells of labellar chemosensilla in the blowfly Protophormia terraenovae to stimulation with sucrose or fructose. In order to ascertain whether Ca(++) conductance is involved, the effects of EGTA, one of the most used Ca(++) chelating agent, and of SK&F-96365, an inhibitor of receptor mediated calcium influx, were also studied. Our electrophysiological data indicate that W-7 addition strongly depresses the 'sugar' chemoreceptor response to both sugars and in the case of sucrose stimulation also influences adaptation rate. The Ca(++) chelator has no significant effects on the response of the 'sugar' cell following stimulation with sucrose, but lowers fructose stimulating effectiveness. In the presence of SK&F-96365 both sucrose and fructose responses are inhibited. A possible transduction mechanism for sugar reception is discussed.
authors.affiliation: Dipartimento di Biologia Sperimentale, Sezione di Fisiologia Generale, Università di Cagliari, Cittadella Universitaria di Monserrato, SS. 554 Km 4.500, I-09042 (CA), Monserrato, Italy
authors.forename: A
authors.initials: A
authors.lastname: Liscia
authors.forename: R
authors.initials: R
authors.lastname: Crnjar
authors.forename: C
authors.initials: C
authors.lastname: Masala
authors.forename: G
authors.initials: G
authors.lastname: Sollai
authors.forename: P
authors.initials: P
authors.lastname: Solari