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PubMed1988

A comparison of cold storage solutions for hepatic preservation using the isolated perfused rabbit liver.

Rabbit livers were stored cold for periods of 6 or 24 hr and tested using the isolated perfused liver model. Five solutions were tested: Eurocollins (EC), Ross and Marshall's hypertonic citrate (HC), modified plasma protein fraction (Cambridge PPF), Ringer lactate, and the recently developed "University of Wisconsin" (UW) solution. After storage livers were perfused with an erythrocyte-free oxygenated Krebs-Henseleit solution containing 4% bovine serum albumin at 38 degrees C for 2 hr. Bile production proved to be the most sensitive index of liver function for discriminating between the various storage solutions and the different preservation times. After 6 hr of cold storage, bile production was similar to control liver bile production (9.8 +/- 2.4 ml/2 hr/100 g) in livers stored in HC (8.8 +/- 2 ml), PPF (9.9 +/- 2.2 ml), and UW (10.3 +/- 1.9 ml); it was slightly depressed in EC (6.7 +/- 2.5 ml, P = 0.06), and markedly depressed in Ringer lactate (4.3 +/- 0.8 ml, P less than 0.05). After 24 hr of cold storage bile production in UW-stored livers was near normal (9.3 +/- 0.7 ml) but significantly depressed (3.5-6.2 ml) in all other solutions tested. Release of enzymes into the normothermic perfusate was also measured (aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase). In this small series the differences between cold storage solutions did not always reach statistical significance although the trend was for less enzyme release in livers stored in UW solution. This technique permits rapid assessment and refinement of new storage methods and new solutions for liver preservation prior to testing in a large animal transplant model. The results suggest that UW solution is superior to other preservation solutions and would permit successful 24-hr storage of livers.

Animals↗
PubMed1991

In vivo intestinal metabolism of 7-ethoxycoumarin in the rat: production and distribution of phase I and II metabolites in the isolated, perfused intestinal loop.

These studies describe the phase I and II metabolism of 7-ethoxycoumarin (7-EC) in the isolated, perfused intestinal loop. Following cytochrome P450-dependent oxidative deethylation of 7-EC by intestinal epithelial cells, the product, 7-hydroxycoumarin (7-HC), undergoes phase II conjugation to form both the glucuronide and sulfate conjugates. The capacity for conjugation of 7-HC within the intestinal epithelium exceeds that of phase I oxidative deethylation, as demonstrated by the absence of increased release of unconjugated 7-HC upon saturation of the conjugation pathways. The formation of both glucuronide (53-62%) and sulfate (41-43%) conjugates contributed to a comparable extent to the overall phase II metabolism of 7-HC within the intestine. This is in contrast to the liver, where sulfate conjugation has been shown to be the predominant phase II metabolic pathway. Furthermore, it was found that unconjugated and sulfate conjugated 7-HC were evenly distributed between the lumenal perfusate and blood compartments, whereas the glucuronide conjugates of 7-HC were preferentially transported at a 4:1 ratio toward the blood. These results indicate that the epithelial cells of the small intestine have the capacity to biotransform orally administered xenobiotics, and the ultimate profile of metabolites generated may influence the biodisposition of these compounds.

Animals↗
PubMed1994

Intracellular calcium transients in potentiated contractions induced by multiple extrasystolic beats in isolated perfused rat hearts.

Mechanisms underlying contractile potentiation induced by multiple extrasystolic contractions (ESC) were evaluated with surface fluorometry in isolated perfused rat hearts loaded with Indo-1/AM. After baseline pacing with a 400 ms interval, 1-25 ESC were interposed with a regular 160 ms interval followed by the postextrasystolic beat with a 400 ms interval. With an increase in the ESC number, left ventricular developed pressure and peak positive dP/dt increased in an exponential manner, reaching a plateau, that was the same for 3 extracellular Ca2+ ([Ca2+]o; 0.55 (n = 9), 1.25 (n = 11) and 2.75 mM (n = 7). Increased [Ca2+]o shifted this relationship left and upward, and with 2.75 mM [Ca2+]o developed pressure and dP/dt decreased after the maximum potentiation was obtained. The relationship between the ESC number and the amplitude of the Indo-1 fluorescence (F400/F510; an index of intracellular Ca2+ ([Ca2+]i)) was also exponential and was shifted left and upward by high [Ca2+]o; however, it lacked the declining phase. Thus, the relationship between the amplitude of F400/F510 and developed pressure or dP/dt consisted of a positively linear part until the maximum potentiation was obtained and a negatively linear part with a further increase in the amplitude of F400/F510. This observation suggests that although contractile potentiation is mediated by increased [Ca2+]i transients, the maximum response might be determined by the responsiveness of the sarcomere.

Animals↗
PubMed1990

Isolated perfused rat kidney as a tool in the investigation of renal handling and effects of nonsteroidal antiinflammatory drugs.

An isolated perfused rat kidney (IPK) preparation is described in which renal perfusion flow, perfusion pressure, urinary flow, urinary pH, and glomerular filtration rate (GFR) are recorded continuously during the perfusion experiment. The usefulness of this IPK system in studying the renal handling and the effects of non-steroidal antiinflammatory drugs (NSAIDs) is shown using salicyluric acid (SU), salicylic acid (SA), and naproxen (NA). Excretion of SU involves glomerular filtration, active secretion, and passive reabsorption. The excretion rates of SA and NA were both much lower than their filtration rate, indicating extensive reabsorption. All three drugs accumulate in the IPK but at different levels. SU accumulates much more than either SA or NA. The effects on renal function were different for the three drugs studied. SU had no effect on kidney function. SA perfusate concentrations greater than 100 micrograms/mL caused diuresis and natriuresis, while SA concentrations less than 100 micrograms/mL did not influence kidney function. NA perfusate concentrations ranging from 0.16 to 25 micrograms/mL caused a decrease in urinary flow and sodium excretion. Very high NA concentrations (greater than 500 micrograms/mL) caused an increase in urinary flow and sodium excretion. We conclude that the IPK is a suitable preparation for characterizing and comparing renal handling and effects of NSAIDs.

Animals↗
PubMed1988

Role of gastrin-releasing peptide in pepsinogen secretion from the isolated perfused rat stomach.

We studied the effects of the neuropeptide gastrin-releasing peptide on pepsinogen secretion using an isolated perfused rat stomach with intact vagal innervation. Following electrical stimulation of the vagus nerves, the pepsin output to the luminal effluent increased from 94 +/- 7 to 182 +/- 24 units pepsin/min and the release of immunoreactive gastrin-releasing peptide to the venous effluent increased from 0.059 +/- 0.014 to 0.138 +/- 0.028 pmol/min. Infusion of gastrin-releasing peptide at 10(-8) M significantly increased pepsin output (from 87 +/- 17 to 129 +/- 22 units pepsin/min) and simultaneous infusion of gastrin-releasing peptide and carbachol at 10(-8) and 10(-6) M, respectively, resulted in an increase to almost 4 times the basal values. Atropine reduced but did not abolish the pepsin response to vagal stimulation and to infusion of gastrin-releasing peptide. Our results suggest that gastrin-releasing peptide participates in the vagal control of pepsinogen secretion.

Animals↗
PubMed1994

Secretion of pancreastatins from isolated, perfused, porcine adrenal glands.

Pancreastatin is a 49 amino acid peptide with a C-terminal glycine amide originally isolated from porcine pancreas. There are strong indications that pancreastatin is derived from chromogranin A, since the amino acid sequence 240-288 in porcine chromogranin A contains pancreastatin flanked by typical signals for proteolytic processing. Several molecular forms of immunoreactive pancreastatin have been reported to be present in porcine adrenal medulla, but no information on the secretion of the peptides is available. We studied stimuli for the release of immunoreactive pancreastatin from adrenal glands as well as the molecular nature of the released immunoreactivity using isolated, perfused, porcine adrenal glands with intact splanchnic nerve supply and a radioimmunoassay specific for the C-terminal glycine amide of porcine pancreastatin in combination with chromatography. Stimulation of the splanchnic nerves greatly enhanced the release of immunoreactive pancreastatin by a mechanism that seems to involve cholinergic nicotinic transmission. The pancreastatin immunoreactivity was due to large amounts of a N-terminally extended pancreastatin form, possibly corresponding to the chromogranin A(1-288) fragment and small amounts of pancreastatin and a C-terminal pancreastatin fragment. Adrenal extracts also contained unprocessed chromogranin A. We conclude that in the porcine adrenals at least 25% of chromogranin A is processed to smaller molecular forms with the pancreastatin sequence forming their C-terminus. These forms appear to be released in parallel with the catecholamines.

Adrenal Glands↗
PubMed1986

The effect of BW 755C and nordihydroguaiaretic acid in the rat isolated perfused mesenteric vasculature.

The suitability of two lipoxygenase inhibitors to study the putative effects of leukotrienes (LTs) in rat isolated perfused mesentery has been assessed. Both the lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) and the dual lipoxygenase and cyclo-oxygenase inhibitor BW 755C depressed vasoconstrictor responses to NA, an effect characteristic of cyclo-oxygenase inhibitors on this tissue. However, depression of responses to NA by NDGA was non-selective since it depressed responses to calcium over the same concentration range. BW 755C possessed some selectivity for inhibition of responses to NA compared to calcium. The difference in relative selectivities between the two inhibitors was confirmed using prostaglandin E2 (PGE2), which reversed responses to NA depressed by BW 755C to a greater extent than those depressed by NDGA. LTC4 and LTD4 neither caused vasoconstriction nor reversed responses to NA depressed by BW 755C. Since NDGA in particular caused depression in this tissue, results using this drug to investigate the possible role of LTs in other blood vessels should be treated with caution.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1986

Distribution of 3H-nitrendipine in the isolated perfused rat heart as revealed by electron microscopic autoradiography.

Subcellular distribution of 3H-nitrendipine was investigated in the isolated perfused rat heart by means of electron microscopic autoradiography. Mechanical measurements of cardiac contractile activity (dP/dt) were performed on the hearts used for autoradiography. There was a non-random pattern of silver grain distribution over the myocardial cells. The grain density, i.e. percentage of total grains/percentage of cell area, was determined for each cell component. A grain density higher than one was noted on the cell membrane, T-tubules and capillaries, indicating a significant incorporation of 3H-nitrendipine into the structures. Concentrations of unlabeled nitrendipine containing radiolabeled nitrendipine caused increased grain density and a decreased contractile activity (dP/dt) by 6% to 30%. It is therefore possible that the pharmacological action of nitrendipine is associated with the localization of 3H-nitrendipine on or in the cell membrane, T-tubules and capillaries.

Animals↗
PubMed1998

Changes in the regulation by endothelium of norepinephrine response in isolated, perfused mesenteric vascular bed of rats at different ages.

Age-related changes of norepinephrine response were studied in isolated perfused mesenteric arteries and veins of rats at 4, 32 and 75 weeks of age. Norepinephrine (0.1-100 nmole) significantly and dose-dependently increased perfusion pressure of the arteries, whereas it only slightly changed that of the veins. The arterial response increased, but the venous response decreased with age. Indomethacin at 5 x 10(-6) M did not change the arterial response at any of the ages. The combination of indomethacin and NG-nitro-L-arginine methyl ester (L-NAME) at 5 x 10(-6) M, and endothelium denudation similarly augmented the response in 4-week-old rats, but neither of these affected the responses in 32- and 75-week-old rats. At raised tone by 100 mM potassium chloride, acetylcholine-induced decrease in perfusion pressure and inhibition of the response by L-NAME were attenuated gradually with age. The raised tone in 75-week-old rats was higher than that in either 4- or 32-week-old rats, but the difference disappeared in the presence of L-NAME. These results demonstrate that the arterial portion is predominant in norepinephrine response and the arterial and venous responses change oppositely with age. It is also suggested that neither prostanoids nor endothelial nitric oxide regulate the arterial response in mature animals, while only in 4-week-old rats, nitric oxide may counteractively regulate the response. Additionally, the roles of nitric oxide in the regulation of transient norepinephrine response, in the regulation of the potassium-induced tonic contracture, and in the vasodilation through muscarinic receptor stimulation seem to change somewhat differently with age.

Acetylcholine↗
PubMed1997

Hepatic extraction of hexarelin, a new peptidic GH secretagogue, in the isolated perfused rat liver.

PURPOSE: To assess the hepatic extraction of hexarelin (HEX), a novel peptidyl GH secretagogue, in the isolated perfused rat model and document the in vitro binding of HEX to plasma proteins using plasma from rats, dogs, pigs, and humans. METHODS: Rat liver was perfused in situ using a recirculating system. The recirculating perfusate consisted of a Krebs Henseleit buffer containing 20% (v/v) prewashed bovine red blood cells, 1% albumin, and lg/L dextrose. Three HEX concentrations of 5, 50, and 500 ng/ml were examined. In vitro plasma binding was determined by the ultrafiltration method. RESULTS: The disappearance rate constant (K), half-life (t1/2), clearance (Cl), and hepatic extraction ratio (E) were: K = 0.013-0.014 min-1, t1/2 = 45-55 min, Cl = 0.345-0.401 ml/min/g liver, and E = 19-21% for the different concentrations of HEX. A linear increase in AUC (270-24334 min pmol/ml) was observed with increasing concentrations. Binding of HEX to plasma proteins of rats, dogs, pigs, and humans was 68.7 +/- 0.8%, 78.7 +/- 0.6%, 67.3 +/- 0.7%, and 65.2 +/- 0.6% respectively. Plasma binding was concentration-independent in the range between 0.003-3 microM for the four species examined. CONCLUSIONS: These results show that 1) the hepatic extraction of HEX is low, 2) the hepatic clearance is concentration independent up to 500 ng HEX/ml of perfusate, and 3) the plasma protein binding of HEX is significant over the dose range studied. HEX exhibits a low hepatic extraction ratio, allowing us to predict that its hepatic clearance may be limited upon HEX protein binding.

Animals↗
PubMed1984

Inhibition of N-nitrosodimethylamine metabolism by ethanol and other inhibitors in the isolated perfused rat liver.

The effects of several potential inhibitors of N-nitrosodimethylamine (NDMA) metabolism have been studied in isolated perfused rat livers. Low concentrations of ethanol (less than 0.5 mM) were found to strongly inhibit hepatic metabolism of NDMA. This effect does not require the metabolism of ethanol. The metabolism and toxicity of NDMA may therefore be influenced by the intake of alcohol as well as by ethanol produced endogenously by the intestinal flora. Other compounds found to inhibit NDMA metabolism include n-propanol, tert-butanol, 4-methylpyrazole, amino-triazole and acetaldehyde.

1-Propanol↗
PubMed1975

Glutamine production by the isolated perfused rat heart during ammonium chloride perfusion.

Myocardial levels of ammonia, glutamate, and glutamine and the release of glutamate and glutamine were studied in the isolated perfused rat heart during perfusion with ammonium chloride, epinephrine, and conditions of anoxia or ischaemia. Perfusion for 15 min with effective ammonium chloride concentrations of 0.53, 0.71, and 2.06 mmol/l resulted in glutamine production of 1.34, 0.95, and 4.41 mmol with 15 min-1/200 dry weight compatible with the presence of glutamine synthetase in rat myocardium. Myocardial ammonium content was unchanged by perfusion with 0.53 and 0.71 mmol/l ammonium chloride, but was increased by 1.36 mumol with 15 min-1/200 mg dry weight by perfusion with 2.06 mmol/l ammonium chloride. Increased myocardial contents of ammonia and glutamine were not accompanied by depression of left ventricular pressure. Perfusion with epinephrine (0.20 mug/ml) resulted in an increased myocardial content of glutamine. Anoxia or ischaemia resulted in no changes in ammonia content, and no changes in glutamine or glutamate production. The net release of glutamine into the perfusate was about 10 times the net release of glutamate.

Ammonia↗
PubMed1999

Metabolism of [14C]phenol in the isolated perfused mouse liver.

A previous report from this laboratory focused on the metabolism of [14C]benzene (BZ) in the isolated, perfused, mouse liver (C. C. Hedli, et al., 1997, Toxicol. Appl. Pharmacol. 146, 60-68). Whereas administration of BZ to mice results in bone marrow depression (R. Snyder et al., 1993, Res. Commun. Chem. Pathol. Pharmacol. 20, 191-194), administration of phenol (P), the major metabolite of BZ, does not. It was, therefore, of interest to determine whether the metabolic fate of P produced during BZ metabolism differed from that of P metabolized in the absence of BZ. Mouse livers were perfused with a solution of [14C]P in both the orthograde (portal vein to central vein) and retrograde (central vein to portal vein) direction to investigate the metabolic zonation of enzymes involved in P hydroxylation and conjugation. Perfusate samples were collected, separated by HPLC, and tested for radioactivity. Unconjugated metabolites were identified by comparing their retention times with nonradiolabeled standards, which were detected by UV absorption. Conjugated metabolites were identified and collected on the basis of radiochromatogram results, hydrolyzed enzymatically, and identified by co-chromatography with unlabeled BZ metabolites. The objective was to compare and quantify the metabolites formed during the perfusion of P in the orthograde and retrograde directions and to compare the orthograde P-perfusion results with the orthograde BZ results reported previously. Regardless of the direction of P perfusion, the major compounds released from the liver were P. phenylgucuronide, phenylsulfate, hydroquinone (HQ), and HQ glucuronide. A comparison of the results of perfusing P in the orthograde versus the retrograde direction showed that more P was recovered unchanged and more HQ was formed during retrograde perfusion. The results suggest that enzymes involved in P hydroxylation are generally closer to the central vein than those involved in conjugation, and that during retrograde perfusion, P metabolism may be limited by the sub-optimal conditions of perfusion. Comparison of the orthograde perfusion studies of P and BZ revealed that a larger percentage of the radioactivity released from the liver was identified as unconjugated HQ after BZ perfusion than after P perfusion. In addition, the amount of radioactivity covalently bound to liver macromolecules was measured after each perfusion and determined to be proportional to the amount of HQ and HQG detected in the perfusate samples.

Animals↗
PubMed1991

Coronary vascular response to endothelin in isolated perfused hearts of spontaneously hypertensive rats.

1. The coronary vasoconstrictive response to endothelin (ET-1) was evaluated using the isolated perfused hearts of 15 week old spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto rats (WKY). Endothelin produced marked increases in perfusion pressure (PP) in both SHR and WKY. The effects of ET-1 were more potent than those of acetylcholine, vasopressin and angiotensin II. The vascular response to ET-1, expressed as the increase in PP, was greater in SHR than in WKY. 2. Nicardipine (10(-8) mol/L) shifted the concentration-PP response curve for ET-1 to the right. The extent of the rightward shift was greater in SHR than in WKY. Additionally in SHR, Bay K-8644 elicited a dose-dependent increase in PP, the effect being more potent than that in WKY. 3. The increased response of the coronary vasculature to ET-1 was observed after 15 weeks of age but not at 6 weeks, indicating that enhancement of the response develops with ageing in SHR. 4. Enhancement of the vascular response to ET-1 in SHR was prevented by chronic (10 weeks) treatment with enalapril (10 mg/kg per day), but not by hydralazine (30 mg/kg per day). 5. These results indicate that the coronary vascular response to ET-1 increases with age in SHR. The mechanism of the enhanced response may involve the activation of dihydropyridine-sensitive Ca2+ channels, however, this type of mechanism may also be modulated at least in part by the renin-angiotensin system.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1989

The influence of amine metabolizing enzymes on the pharmacology of tyramine in the isolated perfused mesenteric arterial bed of the rat.

1. The pressor response to the infusion of tyramine (Tyr) into the isolated perfused mesenteric arterial bed of the rat has been studied at both a low and a high dose (0.2 and 2.0 mumol) and the effect of monoamine oxidase-A (MAO-A) and semicarbazide-sensitive amine oxidase (SSAO) inhibition was examined. Very little MAO-B activity is found in homogenates of this tissue when Tyr is used as substrate. 2. Inhibition of SSAO by treating rats with 1 mg kg-1 (E)-2-(3',4'-dimethoxyphenyl)-3-fluoroally lamine (MDL 72145) 1 h before dissection, had no significant effect on the maximum pressure attained or the area under the curve (AUC) of the response to both low and high doses of Tyr. Inhibition of MAO-A, by inclusion of 10 microM clorgyline in the perfusing fluid, resulted in no significant potentiation at both low or high doses of Tyr. The inhibition of both these enzymes together substantially increased the AUC of the pressor response. 3. Cocaine (3 microM) significantly potentiated the responses to adrenaline (Ad). At this dose, cocaine significantly reduced the peak height and the AUC of the responses to both doses of Tyr. 4. Inhibition of extraneuronal uptake mechanisms with corticosterone (29 microM) did not potentiate the response to Ad and did not significantly alter the response to Tyr (low dose). 5. The effects of MDL 72145 and clorgyline on the directly acting amine, Ad, were studied. MDL 72145 caused a small but significant increase in the EC50 and in the maximum response to Ad, whilst clorgyline (10 microM) increased the EC50 value slightly and decreased the maximum response.

Animals↗
PubMed1983

Effects of quinuronium sulfate pre-exposure on hepatic excretion of sulfobromophthalein (BSP) as measured by isolated perfused rat liver.

Effects of quinuronium sulphate pre-exposure on hepatic excretion of sulfobromophthalein (BSP) as measured by isolated perfused rat liver was investigated. Seventeen rats were used in the study. Rats were divided into controls (Group 1, n = 5), low quinuronium treated animals (Group 2, n = 6), and high quinuronium treated animals (Group 3, n = 6) receiving 0, 1.5 or 2.3 mg quinuronium sulphate/kg intraperitoneally, respectively. Each animal was dosed 30 min. before sacrifice. After 30 min. of equilibrium perfusion, BSP was introduced and the experiment continued for 2 hours. Perfusate and bile were collected at designated time intervals and the volume of bile was noted. BSP in perfusate and bile was assayed. Half-life in minutes (t 1/2 +/- S.E.) of BSP disappearance from perfusate in groups 1, 2 and 3 were 12.5 +/- 1.8, 13.7 +/- 1.0 and 16.8 +/- 3.3, respectively. Group 2 and 3 rats had a significant decrease of BSP excretion in bile (P less than 0.01) compared to group 1 rats. Bile volumes decreased in both quinuronium pre-exposed groups of rats compared to control rats. These observations indicate that quinuronium affects liver function.

Animals↗
PubMed1980

Oxygen supply, oxygen consumption, and endocrine and exocrine secretions of the isolated, perfused, porcine pancreas.

We studied the effect of varying oxygen supply on the endocrine and exocrine secretions of the isolated perfused porcine pancreas utilizing completely synthetic perfusion medium with and without the addition of erythrocytes. With synthetic medium oxygenated to a Po2 of 500 mmHg, oxygen consumption was constant for flow rates at or above 0.5 ml x min-1 x g-1 (wet weight). Addition of erythrocytes to the medium did not increase oxygen consumption at flow rates above this level. Furthermore, the secretion of fluid, bicarbonate and protein in response to secretin and acetylcholine was not influenced by addition of erythrocytes. Similarly, the secretion of insulin, glucagon, pancreatic polypeptide, and somatostatin in response to arginine and acetylcholine was unchanged; arginine stimulated the secretion of all four peptides, whereas acetylcholine stimulated the secretion of insulin and pancreatic polypeptide and inhibited glucagon and somatostatin secretion. The results indicate that the porcine pancreas is respiring adequately, when perfused with a completely synthetic perfusion medium at flows above about 0.5 ml x min-1 x g-1 and Po2 about 500 mmHg, and that addition of erythrocytes is not necessary for the study of its secretory functions.

Acetylcholine↗
PubMed1978

Aldosterone metabolism in isolated perfused rat kidney.

The renal metabolism and handling of [1,2-3H]aldosterone ([3H]A) was studied using isolated perfused rat kidney under different perfusion conditions. The metabolite production rate (MPR) and the urinary excretion of [3H]A together with its radiometabolites (UV/P3H) were studied. Among the formed metabolites, no acid-labile conjugate of aldosterone (ALC) was detected. The MPR was not altered in studies using nonfiltering kidney, a result that suggests that the majority of metabolites were formed without requirement of the process of glomerular filtration and tubular uptake of the hormone. High perfusion pressure (high PP) resulted in a striking increase in whole metabolic clearance rate of aldosterone (MCR[3H]A) due mostly to an enhanced urinary excretion of intact aldosterone and, to a lesser degree, to a significant increase in MPR. Factors determining the excretion rate of [3H]A and its metabolites were than investigated under administration of diuretics. Mannitol (44 mM) induced a marked increase in urine volume (UV) accompanied by a significant UV/P3H increase. Meanwhile, 0.1 mM furosemide resulted in an increase only in UV, but not in UV/P3H. These results revealed the UV dependence of aldosterone excretion in certain diuretic conditions.

Aldosterone↗