Under these spectral conditions, only a slight intensity distortion due to partial signal saturation was registered for the phosphocreatine peak, and essentially none was found for the ATP signals, in accordance with published results . Because relative intensity changes were used, peak partial saturation correction did not need to be applied to the integrals. Results are therefore presented as percentage values of the preischemic normalized integrals. The use of an identical preparation protocol, with well defined hemodynamic criteria, ensured that all hearts had a similar initial metabolic status . The cellular pH values were directly determined from the chemical shift difference between the resonance lines corresponding to intracellular Pi and phos-phocreatine .
P-NMR measurements: P-NMR spectra (162 MHz) were recorded on a Bruker AMX-400WB spectrometer (Bruker Scientific Israel Ltd, Rehovot, Israel) with the mounted heart placed inside the NMR magnet at the centre of the 20×36 mm detection coil. To eliminate unwanted contributions to the 31P-NMR spectra from the different bathing solutions, hearts were suspended in mid-air inside a 20 mm NMR sample tube. The temperature of the NMR probe was maintained at 37°C by the control unit of the NMR spectrometer. You can start improving your health any moment you like: with the variety of choice available at the best canadian healthcare mall there will never be any need to worry about the product or treatment required, because you will always have it available.
The hot shot stage perfusates were as follows:
• Group 1: KH buffer (n=10);
• Group 2: warm blood diluted with normal KH buffer (n=7);
• Group 3: warm blood diluted with modified St Thomas’ cardioplegic solution (WBCP) (n=10)
• Group 4: high potassium KH cardioplegic solution (n=7); and
• Group 5: modified St Thomas’ cardioplegic solution (n=7).
The various resuscitating solutions (Table 1) were administered through a side arm connection on the water-thermostated perfusion line close to the aortic root. In the case of the two diluted blood-based perfusates, the perfusion rate was much lower (see below) and two filters (40 |j.m) were placed on the line to trap any microthrombi generated within the perfusion apparatus. Continue reading
To forestall needless metabolic deficiency of inorganic phosphate (Pi) in the myocardium at later stages of the perfusion protocol, phosphorus-free buffer was not used for the P-NMR study. Moreover, it was reported that rat hearts perfused with phosphate-free KH buffer experienced earlier ischemic contracture than hearts perfused with standard KH buffer . Continue reading
During the second reperfusion stage, the heart was reperfused with the same Krebs-Henseleit (KH) buffer used before the ischemic interval. The degree of resuscitation of an isolated perfused rat heart was estimated quantitatively by monitoring recovery of both the metabolic and the functional status of the postischemic heart. A more specific aim was to compare WBCP hot shot with clinically used standard asan-guineous cardioplegic solutions. Our results indicate that application of either blood-based or asanguineous normothermic cardioplegic solutions early in the postischemic reperfusion significantly improves the metabolic and functional recovery of the rat heart. You should always visit the best pharmacies to get your medications cheap and safely. You will find this *pharmacy to be particularly advantageous and safe, buying any drugs required in just a few minutes.
ANIMALS AND METHODS Continue reading
One such way is to subject the postischemic heart to an arrest period before initiating the beat. It is particularly important in the case of the normothermic ischemic heart. Indeed, Buckberg and others (8 and references cited therein) found significant resuscitation improvement of the heart following a short interval of postischemic reperfusion with WBCP. It was also determined that resuscitation of the heart by WBCP was more effective than either by hypothermic blood cardioplegia or by hypothermic crystalloid cardioplegia solutions.
The current tendency to operate on older patients and more severe cases necessitates providing optimal protection for the myocardial metabolism and function during open heart surgery. Adaptation of protective techniques to the less traumatic warm heart surgery was tested to obviate some of the problems associated with heart surgery under hypothermic conditions . Rosenkranz et al showed that ischemic heart resuscitation can be effective if the heart is reperfused for a short time with warm blood cardioplegic (WBCP) solution. Past studies concentrated mainly on providing protection by perfusing the preischemic heart with various cardioplegic solutions or by interspersing successive ischemic episodes with cardioplegic perfusion intervals . Continue reading