Krebs Henseleit Solution

Isolated rat kidneys perfused with a gassed (95 % O2 and 5 % CO2) albumin-Krebs-Henseleit solution, after 2 h displayed a characteristic pattern of cell necrosis, which was confined to the interbundle region of the outer medulla and was not evident in either the cortex or the inner medulla (Schurek and Kriz 1985). In the outer stripe only those proximal... 

Figure 3. An increase in coronary flow is associated with either an increase or decrease in adenosine tissue levels in isolated guinea pig hearts perfused with Krebs-Henseleit solution. The points to the right of the vertical broken line were obtained by perfusing the hearts with solutions equilibrated with gas mixtures containing various amounts of O2 (numbers beside each point). The points to the left of the vertical broken line show an increase in blood flow by infusion of various concentrations of nitroglycerin in solutions equilibrated with 95% O2. (Reproduced by permission from Progress in Cardiovascular Disease 24 243,1981.)...

Figure 1. Basal metabolism measured in rabbits by a variety of techniques. On the left are some literature myothermic values recorded at 20° C, in the centre of the diagram are some values obtained at IT Cm whole hearts arrested either with high potassium (20 mmol. H) or low calcium (0.1 mmol. H, Ca++ 10 mmol.H, K+) the measurements were made 2 h after cardiectomy. On the right are some values recorded from papillary muscles taken from the same hearts but now bathed in normal Krebs Henseleit solution. The Pq in the oxygen electrode study was 680 torr whilst in the drained myothermic chamber the Pq was —450 torr.

Figure 1 NMR spectrum of a guinea-pig heart perfused with Krebs-Henseleit solution. The spectrum was acquired at 8.7 T using a broad-band probe tuned to 145.8 MHz. Peak assignments are 1, phenylphosphonic acid (external reference) 2, phosphomonoesters 3, inorganic phosphate (P ) 4, phosphocre-atine (PCr) 5, y-phosphorus of adenosine triphosphate (ATP) 6, a-phosphorus of ATP 7, 5-phosphorus of ATP. The spectrum was acquired in 2.5 min by summing 72 free induction decays (FIDs) with a 35 gs pulse and a repetition time of 2 s. Prior to Fourier transformation the FID was subjected to exponential multiplication with a 20 Hz line broadening factor.

Hearts, isolated from Sprague-Dawley rats of either sex (280-368 g) with about 1 cm of the aorta attached, were gently squeezed to remove excess blood and then mounted on a Langendorff apparatus (Edinburgh University staff, 1971). Krebs-Henseleit solution at 37 C was perfused through the heart at a constant pressure and maintained at a constant temperature by circulating water (37°C) in the outer Jacket. After an equilibration period of 30-50 min, responses to the extract were obtained by adding individual bolus doses (0.1-10 mg) to the perfUsion medium. The developed tension was monitored isometrically by a Devices Mx4 pen recorder for 30-40 min after each dose, by which time the hearts had fully recovered from the effects of the extract. 

The cores are subsequently placed in the sheer, and the slicing procedure is performed by advancing the core over an oscillating knife in a controlled environment (Figure 12.1). Cold (4°C) Krebs-Henseleit buffer (pH = 7.4, saturated with 95% O2 and 5% CO2) supplemented with 25 mM glucose is commonly used in preparing the slices [35,38 0], but Williams medium E [41], Earle s balanced salt solutions [37], Sacks preservation medium [42] and V-7 preservation buffer [43,44] are also used. 

In the isolated rat heart perfused according to Langendorff s technique, the 8-hydroxyguanine content in the DNA significantly increased after an ischaemia of 30 or 60 min followed by reperfusion with oxygenated Krebs-Henseleit buffer (You et al. 2000). The levels of 8-hydroxyguanine did not increase either in the ischaemic hearts reperfused with a nitrogenated solution or in the ischaemic-reperfused hearts treated with superoxide dismut-ase, mannitol or allopurinol. 

---