Glibenclamide-sensitive hypotension produced by helodermin assessed in the rat.
Biol Pharm Bull
; 21(12): 1290-3, 1998 Dec.
Article
in En
| MEDLINE
| ID: mdl-9881641
ABSTRACT
The effects of helodermin, a basic 35-amino acid peptide isolated from the venom of a lizard salivary gland, on arterial blood pressure and heart rate were examined in the rat, focusing on the possibility that activation of ATP sensitive K+ (K(ATP)) channels is involved in the responses. The results were also compared with those of vasoactive intestinal polypeptide (VIP). Helodermin produced hypotension in a dose-dependent manner with approximately similar potency and duration to VIP. Hypotension induced by both peptides was significantly attenuated by glibenclamide, which abolished a levcromakalim-produced decrease in arterial blood pressure. Oxyhemoglobin did not affect helodermin-induced hypotension, whereas it shortened the duration of acetylcholine (ACh)-produced hypotension. These findings suggest that helodermin-produced hypotension is partly attributable to the activation of glibenclamide-sensitive K+ channels (K(ATP) channels), which presumably exist on arterial smooth muscle cells. EDRF (endothelium-derived relaxing factor)/nitric oxide does not seem to play an important role in the peptide-produced hypotension.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptides
/
Blood Pressure
/
Heart Rate
Type of study:
Diagnostic_studies
Limits:
Animals
Language:
En
Journal:
Biol Pharm Bull
Journal subject:
BIOQUIMICA
/
FARMACOLOGIA
Year:
1998
Document type:
Article
Affiliation country:
Japan