Hormonal actions of the heart and of lungs on the isolated kidney

Abstract

SUMMARY1. An hormonal influence of the heart on the isolated kidney has been demonstrated by insertion of hearts into pump-oxygenator circuits during renal perfusions.2. This hormone is a steroid which is secreted from the heart into the cardiac venous blood in response to reduction in venous input. The steroid is extractable from heart muscle.3. The actions of the cardiac steroid resemble those of aldosterone but are of shorter latency. Renal blood flow (R.B.F.) and glomerular filtration rate (G.F.R.) rise; urine flow, Na-concentration and Na/K decrease.4. An hormonal influence of lungs on the isolated kidney is also demonstrated. This hormone is not a steroid. It is antidiuretic and Na-retaining: the concentration of urinary Na rises: Na/K remains unchanged. INTRODIUCTIONCat kidneys perfused from heart-lung circuits with heparinized blood from intact animals reabsorbed 990 % of the filtered sodium (Na) and 99-3 % of the filtered water. By contrast, cat kidneys similarly prepared but perfused from pump-oxygenator circuits reabsorbed 96-6 6o of the filtered Na and 98-3 % of the filtered water (Lockett, 1967a).The present purpose was first to determine whether the reabsorption of Na and water by kidneys perfused from pump-oxygenator circuits could be increased by inserting a heart or lungs into the circuit. Secondly, should this be so, to isolate the humoral agent responsible for the improvement in renal function. METHODSOnly methods additional to those described (Lockett, 1967a) are recorded. Dual pump-oxygenator circuit8 were used in thirteen experiments. A single Hooker oxygenator acted as reservoir and oxygenator for two circuits which separately returned blood to this reservoir. These two circuits were each identical with that previously shown (Fig. 1, Lockett, 1967a); they were driven by a pair of Dale-Schuster pumps. The two

Toward a broader understanding of aldosterone in congestive heart failure

“…Extra-adrenal aldosterone production and tissue repair Some 40 years ago, Lockett et al [105][106][107][108][109][110] reported that the beating heart and contracting soleus muscle of cats were sites of steroid generation; the substance resembled 18-D-aldosterone.They found this molecule in coronary venous blood and demonstrated its ability to promote renal salt and water retention. These findings lay fallow until the past decade, when Takeda 111,112 identified the mRNA expression of ALDO synthase (CYP11B2) and ALDO production in rodent vascular tissue.…”

A renally active substance from heart muscle and from blood

“…Corticosterone, cortisone, deoxycorticosterone, hydrocortisone and Reichstein's substance S were obtained commercially from Sigma Chemical Company, St Louis, U.S.A. Biological Heart-lung preparations were made and kidneys were perfused by heart-lung or pumpoxygenator circuits as previously described (Lockett, 1957(Lockett, , 1966(Lockett, , 1967. The blood used to fill the perfusion circuits was collected and all preparations were made in cats initially anaesthetized with ether and then made spinal by destruction of the brain either during temporary occlusion of the carotids (intact donors) or after ligature of the brachiocephalic and L. subclavian arteries (headless donors).…”

Factors controlling the secretion of a substance biologically resembling the 18‐monoacetate of D‐aldosterone by heart muscle

“…Ability to synthesize HS may therefore be a property of all striped muscle. The rate of secretion of HS may not, however, be controlled solely by the frequency of depolarization, but may also be influenced by changes in the contractile state (Lockett, 1967). Hence the present purpose was to determine the influence of fibre length, of change in external work, of digitalization and of procaine on the secretion of HS by the cat heart.…”

“…A substance similar to the 18-monoacetate of D-aldosterone (Lockett, 1967;Ilett & Lockett, 1968;Knox & Lockett, 1969) in its chromatographic and biological properties is secreted into the coronary circulation by the cat heart in vivo (Lockett & Retallack, 1970). Positive correlation is demonstrable between heart rate and the concentration of this substance (HS) in the venous blood entering the R. atrium from the coronary sinus.…”