Effects of nitric oxide and angiotensin II and their interaction on water uptake in Rana catesbeiana.
Nitric oxide and angiotensin II are involved in regulation of water uptake at the pelvic patch of empty-bladder Rana catesbeiana. In whole animal studies, inhibition of nitric oxide synthase decreased water uptake by 25% and decreased the sodium content of skin from the pelvic patch region by 30%. The inhibitor of nitric oxide synthase also had no effects on permeability of isolated, unperfused skin from the pelvic patch region. These studies indicate that nitric oxide is regulating tissue salt concentration. Injection of angiotensin II stimulated water uptake at the pelvic patch by 23%, which was correlated with an increase in both the vascular resistance and the mean arterial pressure in the sciatic artery. Inhibition of nitric oxide synthase enhanced angiotensin II constriction of aortic rings from frogs. However, in the whole animal studies, inhibition of nitric oxide synthase before angiotensin II injection did not enhance water uptake as predicted. It is hypothesized that the pre-capillary bed of the pelvic patch in Rana catesbeiana lacks angiotensin II receptors.
Rea
Mary S
MS
Department of Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. ream2@rpi.edu
Bauby
Heather
H
Babar
Sangeeta
S
Parsons
Robert H
RH
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001834:Body Water / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D009994:Osmolar Concentration; D010539:Permeability / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D011892:Rana catesbeiana / Q000378:metabolism*; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013997:Time Factors
D000804:Angiotensin II; D009599:Nitroprusside; D009569:Nitric Oxide; D012964:Sodium; D011188:Potassium; D019331:NG-Nitroarginine Methyl Ester