Isolation of "myocardial depressant factor(s)" from the ultrafiltrate of heart failure patients with acute renal failure

Cardiac function improvement seen with hemofiltration may be attributable to "cardiac depressant factor(s)" removal. The authors have attempted "factor" isolation. Initial 12 hr hemofiltrate was obtained from: 4 patients with acute congestive heart failure (cardiac index: 2.02 +/- 0.48) and acute renal failure (blood urea nitrogen [BUN] 97.7 +/- 32.7; serum creatinine [SCr] 6.2 +/- 3.4 mg%) (Group I); 8 patients with chronic congestive heart failure (CI: 2.69 +/- 1.3) and mild renal failure (BUN 48.8 +/- 31.4; SCr 3.5 +/- 2.4 mg%) (Group II); and 8 patients with end-stage renal disease and no congestive heart failure (Group III). Crude samples were passed through C18Sep-Pak, and eluted with methanol/water mixtures, and 50% methanol samples were fractionated by high pressure liquid chromatography. Inotropic response was studied by injecting samples (in Krebs-Hensleit buffer) into a Langendorff rat heart preparation. The effect of pH, acetate, salts, and adding propranolol on the inotropic response also was tested. Myocardial depression followed all vehicle and preparatory elements: 0.1 M HCl (-47%); 0.08 M acetic acid (-75%); Na acetate (-25%); 0.1 M NaHCO3 (-11%); Na citrate (-84%); and Na glutarate (-14%). Group I had biphasic responses, the positive inotropism accorded to catecholamines, whereas negative inotropism was equal in each patient (-40.3%). Group II had a biphasic response with negative (-15%) inotropism noted. Group III was weakly biphasic. The data indicate there was myocardial depressive activity, most pronounced in Groups I and II, after method interference was corrected.

Platelet activating factor interaction with tumor necrosis factor and myocardial depressant factor in splanchnic artery occlusion shock

Anaesthetized rats, subjected to total occlusion of the superior mesenteric artery and the celiac trunk for 45 min, developed a severe shock state (splanchnic artery occlusion shock) resulting in a fatal outcome within 75-90 min after release of the occlusion. Shocked rats, treated with an intravenous bolus of L-659,989, a specific platelet activating factor (PAF) receptor antagonist (12.5, 25 or 50 nmol/kg, 4 min after reperfusion followed, 8 min thereafter, by a continuous infusion of 125, 250 or 500 nmol/kg for 30 min), maintained post-release mean arterial blood pressure at significantly higher values than did rats receiving the vehicle. Treatment with L-659,989 significantly increased survival rate, blunted the rise in plasma myocardial depressant factor activity and lowered serum and macrophage levels of tumor necrosis factor (TNF-alpha). In addition, the drug completely restored macrophage phagocytosis, improved macrophage killing and significantly inhibited leukopenia. To investigate the interaction between PAF, TNF-alpha and myocardial depressant factor, the blood levels of these three mediators were evaluated: shocked rats exhibited increased PAF levels with a peak at 30 min. The plasma levels of PAF peaked earlier than did either serum TNF-alpha or plasma myocardial depressant factor. Both peaks occurred 75 min after the release of occlusion. The results of this study therefore suggest that PAF is a key mediator of splanchnic artery occlusion shock and plays a permissive role in inducing the release of other factors (i.e. TNF-alpha and myocardial depressant factor) that are relevant to shock.

Beneficial effects of transforming growth factor-beta and tissue plasminogen activator in splanchnic artery occlusion and reperfusion in cats

We studied the effects of transforming growth factor-beta (TGF-beta), tissue plasminogen activator (tPA), and their combination in cats subjected to splanchnic artery occlusion (SAO) with reperfusion. Untreated anesthetized cats subjected to total occlusion of the celiac, superior, and inferior mesenteric arteries for 120 min, followed by reperfusion, uniformly died within 120 min after reperfusion. The mean survival time was 75 +/- 8 min. Plasma amino-nitrogen concentrations and cathepsin D and myocardial depressant factor (MDF) activities were markedly elevated following reperfusion. Superior mesenteric artery (SMA) rings isolated from cats subjected to SAO with reperfusion exhibited a significant loss of vasorelaxation to the endothelium-dependent dilators acetylcholine and A-23187. Administration of tPA (1 mg/kg) intravenously just before reperfusion did not prolong survival time (81 +/- 10 min) nor did it influence any biochemical or cardiovascular responses following reperfusion or ameliorate the depressed endothelium-dependent relaxation of SMA rings. In contrast, TGF-beta (50 micrograms/cat) ameliorated the SAO postreperfusion state in terms of survival rate and plasma MDF activity, and protected against depressed endothelium-dependent relaxation of SMA rings. TGF-beta alone slightly increased the survival time to 102 +/- 11 min. However, combined treatment with tPA (1 mg/kg) and TGF-beta (50 micrograms/cat) preserved endothelium-dependent relaxation and prevented increases in plasma amino-nitrogen more prominently than TGF-beta given alone and significantly increased the survival time to 118 +/- 3 min (p less than 0.01). These results indicate that TGF-beta exerts beneficial effects in SAO followed by reperfusion in cats, and tPA has an augmenting action on some of the beneficial effects of TGF-beta. These findings suggest that TGF-beta alone or in combination with tPA may be potentially useful therapeutic regimens in splanchnic ischemia shock by preserving splanchnic parenchymal and endothelial cells.

A technique developed for isolated canine papillary muscle function in various plasmas; and utility ascertained with plasma containing myocardial depressant factors

Isolated papillary muscles from young dogs were studied to determine the feasibility of utilizing plasma, without added foam depressants, as a test solution to support muscle function. Diluted canine plasma, undiluted canine plasma, plasma with adjusted protein content, monkey plasma, and plasma containing myocardial depressant factors (MDF) were evaluated. For each test, each papillary muscle served as its own control, with either Krebs-Henseleit solution or a control plasma to establish a basis for evaluation of the test plasma. A technique was implemented to oxygenate the muscle, in plasma, without foam production and to monitor pH continuously. These studies indicated that plasma (diluted, undiluted, or with protein adjustments to accommodate experimental procedural requirements) was a satisfactory test solution. Furthermore, plasma from species unrelated to the dog could be utilized. In utilizing plasma, it was essential to establish or adjust the pH and osmolarity for normal muscle function. These studies with plasma containing MDF indicated that MDF depressed canine papillary muscle function. The Vmax values and Po values were decreased and latency was increased. The effects of MDF in canine papillary muscle preparations were completely reversible in short-term studies (up 10 10 hours' duration).

Pulmonary edema and respiratory insufficiency in acute pancreatitis

Pulmonary edema, cardiac enlargement, and respiratory insufficiency may occur in patients with acute pancreatitis. The mechanisms are complex and incompletely understood, but probable etiologic factors include fluid overload, left ventricular failure, impaired respiratory excursion and microatelectasis, and a nonspecific response of the lung to various types of pulmonary injury including hypotension, intravenous crystalloids, and the effects of circulating pancreatic enzymes. Recognition of the association of pulmonary edema and respiratory insufficiency with pancreatitis is importance because early treatment with positive pressure breathing, careful fluid management and diuretics, and corticosteroids may prevent the development of irreversible respiratory failure.