Atrial natriuretic peptide increases human capillary filtration and venous distensibility.
OBJECTIVE
The main aim of this study was to examine whether atrial natriuretic peptide (ANP) alters capillary filtration and venous distensibility.


METHODS
The study was designed to examine the local effects of i.a. infusion of ANP upon capillary filtration and venous distensibility in human forearms of eight healthy volunteers.


METHODS
Using a water plethysmograph, we measured venous distensibility and capillary filtration from changes in forearm volume when transmural venous pressure was increased in a stepwise manner and held constant during i.a. infusion of saline, ANP and sodium nitroprusside (SNP). The doses of ANP and SNP were chosen to double baseline forearm blood flow obtained during saline infusion.


RESULTS
ANP and SNP infusion both increased venous distensibility to the same extent compared with saline infusion. Capillary filtration was greater during ANP than during saline or SNP infusion. Small vein pressure was comparable during infusion of the two drugs.


CONCLUSIONS
Our results suggest that ANP increases venous distensibility and capillary filtration in human forearms.
Ando
S
S
Research Institute of Angiocardiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Imaizumi
T
T
Harada
S
S
Hirooka
Y
Y
Takeshita
A
A
D000328:Adult; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002199:Capillary Permeability / Q000187:drug effects*; D005542:Forearm / Q000098:blood supply*; D006801:Humans; D007261:Infusions, Intra-Arterial; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D010991:Plethysmography; D012039:Regional Blood Flow / Q000187:drug effects; D012965:Sodium Chloride; D014664:Vasodilation / Q000187:drug effects*; D014680:Veins / Q000187:drug effects; D014690:Venous Pressure / Q000187:drug effects
D009599:Nitroprusside; D012965:Sodium Chloride; D009320:Atrial Natriuretic Factor