Effect of water deprivation and salt loading on atrial natriuretic peptide-stimulated guanylate cyclase activity in the rat subfornical organ.
The effect of water deprivation and salt loading on rat atrial natriuretic peptide (99-126) (rANP)-stimulated guanylate cyclase activity was investigated in the rat subfornical organ. rANP stimulated the formation of cGMP in rat subfornical organ crude homogenates in a dose- and time-dependent manner. An elevated responsiveness to rANP-induced cGMP production was observed in the subfornical organ after 4 days of water deprivation; on the contrary, after salt loading the response to the cGMP-generating effects of ANP were less pronounced than those in the corresponding control tissue. Our results suggest that cGMP mediates at least some of the central actions of rANP through the activation of specific receptors in localized target sites, and they provide evidence suggesting that the guanylate cyclase-coupled ANP-binding sites are susceptible to the regulatory mechanism described in the rat subfornical organ.
Israel
A
A
Faculty of Pharmacy, Institute of Experimental Medicine, Universidad Central de Venezuela, Caracas.
del Rosario Garrido
M
M
Barbella
Y
Y
Becemberg
I
I
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D006152:Cyclic GMP / Q000096:biosynthesis; D004232:Diuretics; D006162:Guanylate Cyclase / Q000378:metabolism*; D007700:Kinetics; D009490:Neurosecretory Systems / Q000201:enzymology*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D013356:Subfornical Organ / Q000187:drug effects / Q000201:enzymology*; D014868:Water Deprivation / Q000502:physiology*
D004232:Diuretics; D010446:Peptide Fragments; D012965:Sodium Chloride; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D006152:Cyclic GMP