What are the methods to use noradrenaline?
Drug solutions were prepared by adding each pharmacological agent to 40 mL of modified Kreb’s solution. Desipramine was prepared as a one mM solution, and noradrenaline was 1x 10-5 M. All other drug solutions were made to have a concentration of 1x 10-6 M. The stock solutions were placed in a 35c water bath. Brains were obtained from rats and placed in a chilled, modified Kreb’s solution. The brain was cut into round slices with approximately a 0.5 mm thickness and a 4 mm diameter, and the masses of these slices were recorded (this was done for us by the lecturer present). Next, four nylon mesh bags were constructed by sewing together two 15 x 15 mm squares of the material.
One brain slice was placed in each bag. Electrodes were made using 0.5 mm stainless steel wire formed into a loop with a 3-5 mm diameter, and the leads were covered in sports. The bags containing brain slices were incubated in 2 mL of modified Kreb’s containing 1 x 10-7 M of the radioisotope [3H]-Noradrenaline for 30 min at 35oC. The solution was kept well aerated using a syringe needle insulated with portex and connected to an air pump. The tissue was allowed tissue to sit in 2 mL of fresh modified Krebs’s solution containing no drug for a maximum of 15 minutes. Finally, a timer was set. In order to measure the basal efflux of 3H-Noradrenaline, brain slices were washed with two mL of fresh modified Kreb’s solution.
The new solution was added every 10 minutes for 40 minutes total, and the old solution was retained for counting. For the electrical stimulation, a student’s electrical stimulator was set at 10 V and a time duration of 1 msec. Each tissue sample received 120 pulses at six different frequencies: 0.5 Hz, 1 Hz, 2 Hz, 5 Hz, 8 Hz, and 10 Hz. Immediately after stimulation, the solution was replaced with two mL of fresh Kreb’s solution, and the old solution was collected as a sample. Then, the tissue was left in solution for a duration of 6 minutes following initial stimulation. The solution was collected as a sample, and a fresh solution was added.