Involvement of nitric oxide in the head regeneration of Hydra vulgaris.
Recent data have shown that a functional NO-cGMP signalling system plays an important role during development and seems to be operative early during the differentiation of embryonic stem cells. The intriguing possibility exists that this role can be evolutionarily conserved between vertebrates and invertebrates. In this paper, we have analyzed the effect of NO-cGMP pathway on the regeneration process in Hydra vulgaris, the most primitive invertebrate possessing a nervous system. Our results indicate that NO production increased during Hydra regeneration. The NOS inhibitor L-NAME reduced the regenerative process and the same effect was obtained by treatment with either the specific guanylate cyclase inhibitor ODQ or the protein kinase G (PKG) inhibitor KT-5823. In contrast, the regeneration process was increased by treating decapitated Hydra with the NO donor NOC-18. Furthermore, we found that cell proliferation was also increased by treating decapitated Hydra with the NO donor NOC-18 and reduced by treatment with the NOS inhibitor L-NAME. Our results strongly suggest that the NO-cGMP-PKG pathway is involved in the control of the proliferative-differentiative patterns of developing and regenerating structures in cnidarians as well as bilaterians.
Colasanti
Marco
M
Department of Biology, University of Rome "ROMA TRE", Viale Marconi 446, 00146 Rome, Italy. colasant@uniroma3.it
Mazzone
Valeria
V
Mancinelli
Livia
L
Leone
Stefano
S
Venturini
Giorgio
G
D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006257:Head; D006829:Hydra / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009603:Nitroso Compounds / Q000494:pharmacology; D012038:Regeneration
D002227:Carbazoles; D004791:Enzyme Inhibitors; C093285:NOC 18; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; C073601:KT 5823; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D017869:Cyclic GMP-Dependent Protein Kinases; D019331:NG-Nitroarginine Methyl Ester