Trial of platelet-derived growth factor antagonist, trapidil, in accelerated nephrotoxic nephritis in the rabbit

The platelet-derived growth factor (PDGF) antagonist, trapidil, which also blocks the thromboxane and/or PG-endoperoxide receptor and is an inhibitor of thromboxane synthetase, was administered during rabbit accelerated nephrotoxic nephritis; the clinical and histological evolution was studied as well as urinary immunoreactive thromboxane (i-TXB2) and immunoreactive prostaglandin E2 (i-PGE2) excretion. Although the dose we used has been shown to be effective in vivo, and it inhibited the urinary i-TXB2 excretion on days 5 and 10, it neither inhibited the enhanced production of i-TXB2 on day 1, nor prevented the glomerular influx of monocytes on days 5 and 10. All clinical and histological data tend to be worse rather than better in trapidil-treated animals on days 5 and 10.     

Thromboxane biosynthesis and platelet function in type II diabetes mellitus

It has been suggested that platelet hyperreactivity in patients with diabetes mellitus is associated with increased platelet production of thromboxane. We therefore compared the excretion of a thromboxane metabolite and platelet function in 50 patients with Type II diabetes mellitus who had normal renal function and clinical evidence of macrovascular disease and in 32 healthy controls. The mean (+/- SD) excretion rate of urinary 11-dehydro-thromboxane B2 was significantly higher in the patients than in the controls (5.94 +/- 3.68 vs. 1.50 +/- 0.79 nmol per day; P less than 0.001), irrespective of the type of macrovascular complication. Tight metabolic control achieved with insulin therapy reduced the levels of 11-dehydro-thromboxane B2 by approximately 50 percent. The fractional conversion of exogenous thromboxane B2 (infused at a rate of 4.5, 45.3, or 226.4 fmol per kilogram of body weight per second) to urinary 11-dehydro-thromboxane B2 was assessed in four patients, in whom it averaged 5.4 +/- 0.1 percent; this value did not differ from that measured in healthy subjects. Aspirin in low doses (50 mg per day for seven days) reduced urinary excretion of the metabolite by approximately 80 percent in four patients. The fact that thromboxane biosynthesis recovered over the following 10 days was consistent with a platelet origin of the urinary metabolite.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of low-dose aspirin on fetal and maternal generation of thromboxane by platelets in women at risk for pregnancy-induced hypertension

There is evidence that aspirin in low doses favorably influences the course of pregnancy-induced hypertension, but the mechanism, although assumed to involve suppression of the production of thromboxane by platelets, has not been established. We performed a randomized study of the effect of the long-term daily administration of 60 mg of aspirin (n = 17) or placebo (n = 16) on platelet thromboxane A2 and vascular prostacyclin in women at risk for pregnancy-induced hypertension. Low doses of aspirin were associated with a longer pregnancy and increased weight of newborns. Serum levels of thromboxane B2, a stable product of thromboxane A2, were almost completely (greater than 90 percent) inhibited by low doses of aspirin. The urinary excretion of immunoreactive thromboxane B2 was significantly reduced without changes in the level of 6-keto-prostaglandin F1 alpha, a product of prostacyclin. Mass spectrometric analysis showed that aspirin reduced the excretion of the 2,3-dinor-thromboxane B2 metabolite--mainly of platelet origin--by 81 percent and of thromboxane B2, probably chiefly of renal origin, by 59 percent. The urinary excretion of 6-keto-prostaglandin F1 alpha and of its metabolite 2,3-dinor-6-keto-prostaglandin F1 alpha was not affected. Low doses of aspirin only partially (63 percent) reduced neonatal serum thromboxane B2. No hemorrhagic complications were observed in the newborns. Thus, in women at risk for pregnancy-induced hypertension, low doses of aspirin selectively suppressed maternal platelet thromboxane B2 while sparing vascular prostacyclin, but only partially suppressed neonatal platelet thromboxane B2, allowing hemostatic competence in the fetus and newborn.     

Urinary excretion of 2, 3-dinor-6-keto prostaglandin F1 alpha and platelet thromboxane formation during ethanol withdrawal in alcoholics.

The excretion of 2,3-dinor-6-keto prostaglandin F1 alpha, a major urinary metabolite of prostacyclin, and the formation of thromboxane B2, a stable metabolite of thromboxane A2, by platelets stimulated by adenosine diphosphate, were studied in alcoholics, who had been admitted for detoxification. Once prolonged heavy drinking had stopped, platelet count and thromboxane formation, calculated either per 10(7) platelets or per litre of blood, significantly increased (p less than 0.05), while the skin bleeding time and urinary excretion of the metabolite of prostacyclin decreased (p less than 0.05). The balance between prostacyclin and thromboxane therefore seemed to favour the excretion of prostacyclin while it shifted to favour thromboxane formation about a week later.     

Effects of orally administered glandular kallikrein on urinary kallikrein and prostaglandin excretion,plasma immunoreactive prostanoids and platelet aggregation in essential hypertension

Summary The effects of orally administered glandular kallikrein on urinary kallikrein, aldosterone and prostaglandin E (PGE) excretion, plasma renin activity (PRA), immunoreactive 6-keto PGF₁ and thromboxane B₂ concentrations and platelet aggregation were studied in 12 patients with essential hypertension (EH). After a 2-week control period, each patient was given orally 450 KU/day of hog glandular kallikrein for 8 weeks. Urinary kallikrein, aldosterone and PGE excretion, and plasma 6-keto PGF₁ and thromboxane B₂ concentrations were measured by radio-immunoassay. Platelet aggregation was measured by the addition of ADP, collagen or ristocetin with an aggregometer. Urinary kallikrein excretion and plasma 6-keto PGF₁ concentration were significantly decreased in patients with EH. There were no significant differences in PRA, urinary aldosterone excretion and plasma thromboxane B₂ concentrations between control subjects and patients with EH. There was a significant decrease in blood pressure in patients with EH coinciding with significant increases of urinary kallikrein and PGE excretion and plasma immunoreactive 6-keto PGF₁ concentration after administration of glandular kallikrein. There was also a significant inhibition of platelet aggregation induced by collagen in these patients. Thus, a suppression of the kallikrein-kinin-prostaglandin system in patients with EH was found, and a decrease in blood pressure with an increment of urinary kallikrein, PGE excretion, plasma immunoreactive 6-keto PGF₁ and inhibition of platelet aggregation in vivo by the administration of glandular kallikrein.Abbreviations BK bradikinin - EH essential hypertension - KU kallikrein unit - PG prostaglandin - PRA plasma renin activity - PRP platelet rich plasma - TX thromboxane Presented at IXth European Congress of Cardiology Düsseldorf, July 8–12, 1984     

CI-959, a new, potential antiallergic drug, inhibits mediator release from lung and contractions of human airways in vitro.

Many symptoms of the immediate allergic response can be attributed to the synthesis/release and subsequent actions of histamine and metabolic products of arachidonic acid oxidation. CI-959 [5-methoxy-3-(1-methylethoxy)-N-1H-tetrazole-5-yl-benzo(b) thiophene-2-carboxamide], a new, potential antiallergic drug, inhibited the release of histamine, immunoreactive sulfidopeptide leukotrienes C4, D4 and E4 and immunoreactive thromboxane B2 from immunologically activated guinea-pig and human lung cells in vitro. The IC50s of CI-959 using guinea-pig lung were: histamine, 0.8 +/- 1.4 microM; leukotriene, 0.7 +/- 1.6 microM and thromboxane, 9.6 +/- 3.3 microM. Using human lung the IC50s were: 2.3 +/- 1.3 microM for histamine; 0.3 +/- 5.1 microM for leukotriene, and 0.3 +/- 2.6 microM for thromboxane. CI-959 caused a concentration-dependent inhibition of anti-IgE-induced contractions of human bronchial muscle. Mean percent inhibitions were 45, 65 and 96 at 1, 3 and 10 microM, respectively. Cromolyn, 10 microM, inhibited bronchial contractions only 42%. The ability of CI-959 to inhibit these immunologically induced contractions indicates that the release of all mediators responsible for bronchoconstriction was effectively inhibited. These data suggest that CI-959 may be effective in preventing the development of symptoms directly related to inflammatory mediator release in a variety of allergic and inflammatory states.     

川芎嗪对大鼠被动型Heymann肾炎病变的影响

建立ＳＤ大鼠典型的被动型Ｈｅｙｍａｎｎ肾炎（ＰＨＮ）模型,观察川芎嗪对肾内血栓素Ａ２（ＴｘＡ２）．前列环素Ｉ２（ＰＧＩ２）及ＴＸＡ２－ＰＧＩ２平衡的影响。结果表明：川穹嗪能够降低大鼠尿中的ＴＸＡ２而提高ＰＧＩ２的含量。此外,对于减少尿蛋白的分泌及肾组织学的损伤也有一定的作用。提示川芎嗪可用于ＰＨＮ病变的防治。     

Short lasting increase in urinary specific kallikrein activity during long term administration of furosemide

Furosemide was administered for seven days to normal rats. Urinary kallikrein excretion showed a biphasic response during the seven consecutive days of study. During the initial three days only the kininogenase activity showed a significant increase without any variation in the excretion of the immunoreactive kallikrein. The specific urinary kininogenase activity was therefore enhanced. After three days of furosemide administration, both the urinary kininogenase activity and urinary immunoreactive kallikrein were augmented. The urinary specific kininogenase activity was that time no more different when compared to the basal value. Considering the delay time of three days, this second part of the response could be a mineralocorticoid mediated effect. In this respect, kidney level of immunoreactive and kininogenase activity of kallikrein are also increased after seven days of furosemide administration. However the short lasting increase in urinary specific kininogenase activity observed during the initial three days is due to a change in the ratio active versus inactive kallikrein without any variation of total kallikrein. It is possible that this immediate response results of a direct effect of furosemide acting either on the preferential excretion of the active form or on the activation of the prokallikrein in the urine.     

In vivo indexes of platelet and vascular function during fish-oil administration in patients with atherosclerosis

Populations that consume a diet rich in marine lipids may have a lower risk of atherosclerotic disease. Fish oil contains the N-3 polyunsaturated fatty acid eicosapentaenoate, and the biosynthesis of thromboxanes and prostacyclins from eicosapentaenoate (thromboxane A3 and prostaglandin I3), rather than from the usual precursor arachidonate (thromboxane A2 and prostaglandin I2), may help to reduce the risk. To examine this hypothesis, we studied the effect of eicosapentaenoate supplementation (10 g per day) for one month on the synthesis of thromboxanes and prostacyclins, as assessed by urinary metabolite excretion, in six patients with peripheral vascular disease and seven normal controls. Supplementation markedly increased the eicosapentaenoate content of phospholipids from red cells and platelets. Synthesis of the platelet agonist thromboxane A2, which was elevated in the patients at base line, declined by 58 percent during supplementation but did not reach normal values. The decline in thromboxane A2, which is synthesized from arachidonate, coincided with the formation of the inactive thromboxane A3, which is synthesized from eicosapentaenoate. A lower dose of eicosapentaenoate (1 g per day) was not sufficient to maintain the changes in thromboxane A2 synthesis. Platelet function was only moderately inhibited during eicosapentaenoate supplementation, consistent with incomplete suppression of thromboxane A2 synthesis. These studies show that a high dose of eicosapentaenoate alters the pattern of synthesis of thromboxanes and prostacyclins. However, effects comparable to those of aspirin require long-term administration in high doses. Whether other properties of fish oil might render it a more attractive antithrombotic therapy remains to be determined.     

Decreased passage of the nonapeptide dDAVP over the intestinal epithelium during development in the young rat

The nonapeptide 1-deamino-cysteine-8-D-arginine vasopressin (dDAVP) was gavage-fed together with cow's milk whey protein to young, developing rats. The transepithelial passage of dDAVP in the gastrointestinal (GI) tract was assessed by a specific RIA as immunoreactive levels in blood serum extracts and as urinary excretion of dDAVP 0.5-8 h after feeding. In 14-day-old rats the passage of dDAVP was higher than in 30-day-old rats, since the 14-day-old rats had significantly higher serum levels (5-10 times) 0.5-2 h after feeding and a urinary excretion approaching 0.15% of the administered amount after 8 h. In the 30-day-old rats urinary excretion increased up to 0.05% after 2 h and then levelled off. It was also clear that 30-day-old rats had a slower transfer to and faster elimination from serum than 14-day-old rats. dDAVP appeared to be passed over the GI tract mucosa independently of intestinal proteolysis since feeding it to 30-day-old rats together with the proteinase inhibitors, soya-bean trypsin inhibitor and pepstatin did not influence the serum or urinary levels. Thus, dDAVP was taken up from the GI tract into the blood circulation and excreted in the urine of young rats. The decrease in the passage of dDAVP found around weaning appears to be related to developmental processes affecting the permeability of the intestinal epithelium rather than intestinal proteolysis.     

An imbalance between the excretion of thromboxane and prostacyclin metabolites in pulmonary hypertension.

BACKGROUND. Constriction of small pulmonary arteries and arterioles and focal vascular injury are features of pulmonary hypertension. Because thromboxane A2 is both a vasoconstrictor and a potent stimulus for platelet aggregation, it may be an important mediator of pulmonary hypertension. Its effects are antagonized by prostacyclin, which is released by vascular endothelial cells. We tested the hypothesis that there may be an imbalance between the release of thromboxane A2 and prostacyclin in pulmonary hypertension, reflecting platelet activation and an abnormal response of the pulmonary vascular endothelium. METHODS. We used radioimmunoassays to measure the 24-hour urinary excretion of two stable metabolites of thromboxane A2 and a metabolite of prostacyclin in 20 patients with primary pulmonary hypertension, 14 with secondary pulmonary hypertension, 9 with severe chronic obstructive pulmonary disease (COPD) but no clinical evidence of pulmonary hypertension, and 23 normal controls. RESULTS. The 24-hour excretion of 11-dehydro-thromboxane B2 (a stable metabolite of thromboxane A2) was increased in patients with primary pulmonary hypertension and patients with secondary pulmonary hypertension, as compared with normal controls (3224 +/- 482, 5392 +/- 1640, and 1145 +/- 221 pg per milligram of creatinine, respectively; P less than 0.05), whereas the 24-hour excretion of 2,3-dinor-6-keto-prostaglandin F1 alpha (a stable metabolite of prostacyclin) was decreased (369 +/- 106, 304 +/- 76, and 644 +/- 124 pg per milligram of creatinine, respectively; P less than 0.05). The rate of excretion of all metabolites in the patients with COPD but no clinical evidence of pulmonary hypertension was similar to that in the normal controls. CONCLUSIONS. An increase in the release of the vasoconstrictor thromboxane A2, suggesting the activation of platelets, occurs in both the primary and secondary forms of pulmonary hypertension. By contrast, the release of prostacyclin is depressed in these patients. Whether the imbalance in the release of these mediators is a cause or a result of pulmonary hypertension is unknown, but it may play a part in the development and maintenance of both forms of the disorder.     

Selective inhibition of platelet thromboxane generation with low-dose aspirin does not protect rats with reduced renal mass from the development of progressive disease.

Rats with extensive renal mass reduction develop hypertension, proteinuria and progressive glomerulosclerosis. Previous studies have demonstrated that these changes are associated with an increased urinary excretion of thromboxane compared with normal rats and that the administration of a thromboxane synthetase inhibitor prevents glomerulosclerosis and progressive renal function deterioration. On this basis it has been speculated that the thromboxane synthetase inhibitor, by inhibiting platelet thromboxane, reduces platelet aggregation and prevents the generation of substances that can influence glomerular functional properties. Because the thromboxane synthetase inhibitor also inhibits thromboxane synthesis by resident glomerular cells and lowers blood pressure in these animals, the question of whether platelet thromboxane is indeed the factor implicated in the development of renal disease after renal ablation remains unanswered. To address this issue the authors administered at different time intervals from the surgical procedure a low-dose of oral aspirin (ASA) to rats with remnant kidney. This approach resulted in selective inhibition of platelet cyclooxygenase leading to an almost complete prevention of platelet thromboxane generation. Low-dose ASA spared renal cyclooxygenase as documented by a lack of significant inhibition of glomerular and urinary 6-keto-PGF1 alpha and did not lower blood pressure. Renal function studies showed that low-dose ASA, despite inhibiting platelet aggregation, had no effect on proteinuria and progressive renal insufficiency irrespectively if administered late (ie, 80 days after surgery) and given daily for all the observation period (ie, 20 days) or earlier in the course of the disease (ie, 40 and 10 days after surgery). Histologic data showed that the degree of glomerulosclerosis and tubulo-interstitial damage was not significantly different in rats with reduction of renal mass alone compared with rats with remnant kidney given low-dose ASA. In conclusion, the present findings indicate that inhibition of platelet aggregation and thromboxane formation does not prevent the progressive glomerulosclerosis that develops in rats with surgical reduction of renal mass. It is suggested that the beneficial results obtained previously in the same model by the use of a thromboxane synthesis inhibitor must be attributed either to an effect on resident glomerular cell thromboxane synthesis or to lowering systemic blood pressure.     

Effect of nicotine infusion in humans on platelet aggregation and urinary excretion of a major thromboxane metabolite

The objective of this study was to evaluate further a possible role of nicotine as a stimulator of platelet aggregability and platelet arachidonic acid metabolism in vivo. In six healthy, non-smoking males, platelet aggregability was assessed by filtragometry and impedance aggregometry before, during and after an intravenous infusion of nicotine at two different doses (0.25 and 0.5 μg kg^-1 min^-1) for 30 min. The aggregatory response was also measured after the addition of nicotine at final concentrations ranging from 10^-11 mol L^-1 to 10^-5 mol L^-1 directly to the aggregating blood. The synthesis of thromboxane A₂ (TxA₂) in platelets was estimated by quantitating the urinary excretion of 2,3-dinor-thromboxane B₂ (Tx-M). Despite the plasma concentrations of nicotine, cotinine and catecholamines in the range of those occurring during acute cigarette exposure, the excretion of Tx-M (204±36 pg mg^-1 creatinine) remained unaltered during nicotine infusion. Similarly, platelet aggregatory response to collagen was not influenced by nicotine when infused or added in vitro. However, an enhanced aggregability was detected by filtragometry during the infusion of nicotine at the higher dose employed. The results indicate that nicotine, infused at moderate doses, produces a weak platelet stimulation that is not accompanied by significant release of thromboxane A₂, as monitored by urinary excretion of Tx-M. Although a direct action of nicotine on platelets cannot be excluded, it appears more likely that the enhancement of platelet function is mediated by other, secondary mechanisms.     

Effects of celecoxib on major prostaglandins in asthma

Background Prostaglandin (PG) D₂ is a pro‐inflammatory and bronchoconstrictive mediator released from mast cells, and is currently evaluated as a new target for treatment of asthma and rhinitis. It is not known which cyclooxygenase (COX) isoenzyme catalyses its biosynthesis in subjects with asthma. Objectives Primarily, to assess whether treatment with the COX‐2 selective inhibitor celecoxib inhibited biosynthesis of PGD₂, monitored as urinary excretion of its major tetranor metabolite (PGDM). Secondarily, to determine the effects of the treatment on biosynthesis of PGE₂, thromboxane A₂ and PGI₂, also measured as major urinary metabolites. Methods Eighteen subjects with asthma participated in a cross‐over study where celecoxib 200 mg or placebo were given b.i.d. on 3 consecutive days following 2 untreated baseline days. Six healthy controls received active treatment with the same protocol. Urinary excretion of the eicosanoid metabolites was determined by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Lung function was followed as FEV₁ and airway inflammation as fraction of exhaled nitric oxide (F_ENO). Results Celecoxib treatment inhibited urinary excretion of PGEM by 50% or more in subjects with asthma and healthy controls, whereas there was no significant change in the excretion of PGDM. In comparison with the healthy controls, the subjects with asthma had higher baseline levels of urinary PGDM but not of PGEM. The 3‐day treatment did not cause significant changes in FEV₁ or F_ENO. Conclusion and Clinical Relevance Biosynthesis of PGD₂ was increased in subjects with asthma and its formation is catalysed predominantly by COX‐1. By contrast, COX‐2 contributes substantially to the biosynthesis of PGE₂. The asymmetric impact of celecoxib on prostanoid formation raises the possibility of long‐term adverse consequences of COX‐2 inhibition on airway homeostasis by the decreased formation of bronchodilator PGs and maintained production of increased levels of bronchoconstrictor PGs in asthmatics. Cite this as: K. Daham, W.‐ L. Song, J. A. Lawson, M. Kupczyk, A. Gülich, S.‐E. Dahlén, G. A. FitzGerald and B. Dahlén, Clinical & Experimental Allergy, 2011 (41) 36–45.     

Adenosine 3',5' cyclic monophosphate, calcium and magnesium excretion in ethanol intoxication and hangover.

Effect of ethanol on adenosine 3', 5' cyclic monophosphate (cAMP), calcium (Ca) and magnesium (Mg) excretion was studied in controlled clinical conditions in man. Seven male volunteers served as their own controls. In 5 subjects cAMP excretion was primarily suppressed by ethanol. Ethanol appeared to have a biphasic effect on Ca excretion, an initial stimulation followed by a conservation phase. Mg excretion was stimulated by ethanol in 5 subjects. Subjects having nausea and vomitus and the most severe hangover symptoms had the lowest urinary Ca excretion and the lowest imitial cAMP excretion. Ca and Mg metabolism and the susceptibility of the body to the toxic effects of ethanol appeared to be interrelated.     

Renal responsiveness to parathyroid hormone in a case of nonfamilial hypophosphatemic osteomalacia

Summary Plasma immunoreactive parathyroid hormone level, urinary excretion of adenosine cyclic 3,5-monophosphate (cyclic AMP) and the sensitivity of the renal tubule to calcium infusion and to parathyroid extract were investigated in a patient with nonfamilial hypophosphatemic osteomalacia. Plasma immunoreactive parathyroid hormone concentration was normal and basal urinary excretion of cyclic AMP was increased. Renal cortical adenylate cyclase, as measured by urinary cyclic AMP excretion, was certainly as sensitive to exogenous parathyroid extract as in normal subjects. After a previous calcium infusion, a greater parathyroid-hormone-sensitive component of phosphorus transport in the kidney was present than in two control subjects. Our results indicate that in nonfamilial hypophosphatemic osteomalacia the renal tubule could be hyperresponsive to parathyroid hormone.This work was supported by a grant (n^o 20,463) from the Belgian Nationaal Fonds voor Geneeskundig Wetenschappelijk Onderzoek     

Urinary LDH isoenzyme 5 excretion in experimental pyelonephritis.

Studies to determine the effect of kidney parenchymal infection upon urinary lactic dehydrogenase (ULDH) isoenzyme composition were performed in 12 female Sprague-Dawley rats on Day 0 and on Days 2, 5, and 10, after experimental inducement of Escherichia coli pyelonephritis. An additional group of 12 animals was subjected to similar experimental manipulations and served as sham controls. Repeated 12-h urine collections revealed lower urine osmolalities and significantly higher levels of ULDH 5 excretion in the experimental than in the sham operated animals (P less than 0-05). These differences persisted for the length of the experiment (10 days). Leucocyte excretion rates were also higher in the experimental than in the sham group, and a high correlation with ULDH 5 activity was demonstrated (r = 0-815). No other evidence that the two variables may be causally related was found.     

Thromboxane biosynthesis and platelet function in type I diabetes mellitus

It has been speculated that platelet activation may contribute to the evolution of vascular complications in patients with Type I diabetes mellitus. To address this hypothesis, we measured the plasma and urinary metabolites of thromboxane, presumably of platelet origin, and of prostacyclin, derived from endothelial cells, in addition to more conventional indexes of platelet function. Urinary excretion of the metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha did not differ between diabetics with or without retinopathy and nondiabetic controls. Furthermore, measurement of platelet granule constituents, the aggregation responses to ADP or arachidonic acid, and levels of serum thromboxane B2 failed to discriminate between the groups. The institution of tight diabetic control with multiple daily injections of insulin failed to alter either urinary metabolite excretion or plasma levels of 11-dehydro-thromboxane B2. Conversely, insulin-induced hypoglycemia failed to alter the concentrations of plasma or urinary thromboxane metabolites in nondiabetic volunteers, despite a mean 60-fold increase in plasma epinephrine. These studies suggest that platelet activation does not precede the development of microvascular complications in patients with Type I diabetes who lack clinical evidence of macrovascular disease and have normal renal function. Furthermore, it is unlikely that platelet activation due to intermittent hypoglycemia contributes to the reportedly accelerated development of retinopathy in such patients, when they are subject to tight diabetic control.     

Adenosine 3‘, 5’ cyclic monophosphate,calcium and magnesium excretion in ethanol intoxication and hangover

Effect of ethanol on adenosine 3′, 5′ cyclic monophosphate (cAMP), calcium (Ca) and magnesium (Mg) excretion was studied in controlled clinical conditions in man. Seven male volunteers served as their own controls. In 5 subjects cAMP excretion was primarily suppressed by ethanol. Ethanol appeared to have a biphasic effect on Ca excretion, an initial stimulation followed by a conservation phase. Mg excretion was stimulated by ethanol in 5 subjects. Subjects having nausea and vomitus and the most severe hangover symptoms had the lowest urinary Ca excretion and the lowest initial cAMP excretion. Ca and Mg metabolism and the susceptibility of the body to the toxic effects of ethanol appeared to be interrelated.     

Factors affecting the glomerular protein leak after polyclonal activation in the HgCl2-induced model of anti-GBM disease in the brown Norway rat.

The administration of the polyclonal activator HgCl2 (1 mg/kg i.p.) to Brown Norway (BN) rats on days 0, 2, 4 and 7 resulted in the cyclical production of anti-glomerular basement membrane (GBM) antibodies, the first peak of which occurred at day 14 with a smaller peak at day 26. Glomerular anti-GBM antibody levels were also raised at day 14. Renal injury as measured by urinary loss of albumin and complement (C3) was also cyclical, being maximal on days 15 and 23-26. However, urinary protein excretion was significantly diminished on the days corresponding to the first peak of circulating antibody levels if peripheral monocyte counts were reduced by the repeated injection of anti-monocyte antiserum. Protein excretion was also reduced after the administration of anti-polymorphonuclear neutrophil (PMN) antiserum. Finally, glomerular protein excretion was independent of depletion of serum C3 levels to less than 10% of pooled normal sera by the repeated administration of Cobra Venom Factor (CVF) on days 9 and 11. These findings demonstrate that in the absence of progressive tissue injury in this model, glomerular protein excretion fluctuates according to circulating levels of anti-GBM antibody and that, despite being independent of complement, tissue injury may be increased in the presence of complement activation.