Changes of 31P metabolism during mucus secretion in the slug (Incilaria bilineata)

Abstract

1. Changes in the amounts of mucus secreted by the epidermis of the slug in response to an irritant chemical substance (NaCl) and the effect of mechanical stimulation on high-energy phosphorylation metabolism were studied.

2. ³¹P signals obtained from the slug with in vivo³¹P nuclear magnetic resonance (NMR) spectroscopy included phosphonate, sugar phosphate (SP), inorganic phosphate (Pi), arginine phosphate (Arg-P), and ATP (γ, α and β).

3. When the slug epidermis came into contact with NaCl or was exposed to mechanical stimulation, the concentration of Arg-P decreased and that of Pi increased along with mucus secretion.

4. The change of ³¹P signals in response to chemical stimulation was much more variable than that in response to mechanical stimulation.

5. The β-ATP concentration was dependent on the amount of mucus secreted.