Nitric oxide and prostaglandins are involved in the macula densa
control of the renin system.
Schricker, Karin, Marlies Hamann, and Armin Kurtz.
Physiologisches Institut der Universit[umlaut]at Regensburg,
Germany
APStracts 2:0104F, 1995.
This study aimed to examine the involvement of prostaglandins and of
nitric oxide (NO) on the macula densa dependent activation of the
renin system in vivo. For this purpose male Sprague Dawley rats were
chronically infused with furosemide (12 mg/day) for six days to
inhibit macula densa salt transport. To inhibit the synthesis of
prostaglandins and of nitric oxide animals were injected with
indomethacin (2 mg/kg twice the day) and with L-nitro-arginine
-methylester (L-NAME; 40 mg/kg twice the day) for the last two days of
the experiment, respectively. Furosemide infusion increased plasma
renin activity (PRA) from 8.8+/-1.4 ng ANGI/h x ml to 415.2 ng ANGI/h
x ml and renin m-RNA levels from 112+/-8% of standard to 249+/-18% of
standard. After treatment with indomethacin the furosemide induced
increase in renin mRNA levels was attenuated to 190+/-11% of
standard. After injections of L-NAME both the furosemide induced
rises of renin m-RNA levels and of PRA were reduced, to 126+/-14% of
standard and 22+/-5 ng ANGI/h x ml, respectively. These findings
suggest that activation of renin gene expression by blockade of the
macula densa function is dependent on intact NO and prostaglandin
formation, whilst for stimulation of renin secretion only intact NO
formation appears to be necessary.
Received 20 April 1995; accepted in final form 12 June 1995.
APS Manuscript Number F126-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 July 1995.