The effects of enalapril on the natriuretic response evoked by an oral sodium load in sodium deprived normotensive and hypertensive rats.
Previous studies have shown that an oral sodium load during sodium deprivation is excreted faster than an intravenous load. We wanted to study whether the renin-angiotensin-aldosterone system might be associated with this phenomenon and therefore the influence of the angiotensin converting enzyme (ACE) inhibitor enalapril was investigated. The experiments were performed on four strains of rat: spontaneously hypertensive rats (SHR), Wistar-Kyoto (WKY) rats, inbred hypertension-prone (SS/Jr) and hypertension-resistant (SR/Jr) Dahl rats. In SHR and WKY rats pretreated with enalapril it was observed that an intravenous sodium load induced a renal sodium excretion which was between two and five times larger than that seen after an oral load. In SR/Jr and SS/Jr rats the sodium excretion was the same regardless of the route of administration. In SS/Jr rats sodium excretion increased three- to fourfold upon sodium repletion, whereas no significant increase was observed in SR/Jr rats. Thus, the present results indicate that an intact renin-angiotensin system is necessary for the interplay between the gastrointestinal tract and kidney.
Mu
J Y
JY
Department of Physiology, Göteborg University, Sweden.
Johansson
M
M
Lundgren
O
O
D000284:Administration, Oral; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D004068:Digestive System Physiological Phenomena; D004656:Enalapril / Q000494:pharmacology*; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology*; D007275:Injections, Intravenous; D007668:Kidney / Q000502:physiology; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology; D012964:Sodium / Q000008:administration & dosage; D012982:Sodium, Dietary / Q000008:administration & dosage*
D000959:Antihypertensive Agents; D012982:Sodium, Dietary; D004656:Enalapril; D012964:Sodium