What does ringers solution do to a frog

This investigation was supported by PHS grant no. Public Health Service. Reprints and Permissions. Gourley, D. The potassium concentration of frog Ringer's solution. Experientia 18, 21—22 Download citation.

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Cadmium Chloride. As shown in Figure 6, applying cadmium chloride moderately attenuated heart contraction strengths. Compared to the normal condition, the P-wave in this test was notably elevated to positive values, while the QRS segment shortened its duration and an additional S-spike appeared.

As shown in Figure 7, heat contractions were moderately strengthened following the introduction of epinephrine, while no noticeable change was seen in the heartbeat rate, which was about 30 BPM at the baseline. The magnitude of the ECG signal was increased. Figure 5. Heart contractions and ECG signals before and after applying caffeine on the heart surface.

Figure 6. Figure 7. Heart contractions left and the ECG voltages right before and after applying epinephrine. After applying ACh solutions, the strength of heart contractions dropped from 0. The right panel of Figure 8 shows the ECG signal was also amplified in magnitude. We noted that the baseline signal and contractions became much weaker from then on compared to what they had been at the beginning of the experiment, as can be observed by comparing Figure 5 and Figure 8.

The heart bad been exposed to tests for two hours by that time, and it could not maintain normal activities for lack of nutrition and oxygen. The heart activity was largely haltered following the application of atropine, as demonstrated by Figure 9. Periodic contractions was replaced by a single, relatively long-standing heart beat during the observing period , implying that the heart beat was greatly suppressed.

The KCl was supposed to kill the heart, terminating all cardiac activities, and the results confirmed this conjecture Figure Heart contractions nearly disappeared, nor could normal ECG impulses be detected any more. Contraction strengths of myocardial muscles are known to increase in proportion with the preload tension or the stroke volume, as described by the Frank-Starling mechanism.

Our result Figure 3 is in accordance with this well-known feature of the heart. On the other hand, the Frank-Starling mechanism also states that the contraction strength would drop down after the pre-tension reaches an optimal level which gives rise to the maximum contraction strength. We did not observe this reversing phase. The most likely reason is that the strain we exerted had never reached that maximum contraction point.

The use of cold solution tests the thermal response of the heart. Figure 4 shows the contraction force, the heartbeat rate, and the amplitude of ECG voltages all decrease as the temperature drops. The low temperature lowers the concentration of calcium ions in cell fluids, and hence reduces the contraction force.

The slowed down heartbeat rate and attenuated ECG signals may be attributed to the slow-down metabolic activities of the heart. Frogs are ectothermic animals which need to maintain low metabolic rates in low temperature. Cadmium chloride. Some literatures on internet reported that the cadmium choloride decreases the membrane action potential, which is manifested by a shortened QT interval in the external electrocardiogram.

Our empirical findings were in agreement with this statement. Cadmium is a heavy metal, which in general may inhibit enzymes by reversibly combining with their sulfhydril groups.

In this way, Cadmium may block the propagation of activation impulse from the membrane to the contractile elements, thus reducing the heart output.

Achieving this function necessarily demands increasing the heart output, and epinephrine increases the stroke volume and heartbeat rates. Figure 7 shows the contraction-strengthening effect by enlarging the stroke volume, but the heart rate was not distinctively promoted in our experiment. Acyetlcholine ACh. The ACh is a neurotransmitter that induces contraction of skeletal muscles but decreases contraction of cardiac muscles.

Many of the Ringer's solutions used experimentally are listed in Table 4 , which is divided into sections for Invertebrates, Fish, and Other Vertebrates. Recipies for their preparation are provided in Tables 5 , 6 , and 7 , respectively. Additional details on Ringer's characteristics and usage may be found in Notes and Literature Cited ; for further information, the comprehensive work by Burton is recommended.

Researchers initiating work are urged to select physiological solutions carefully for the particular species to be studied, and to consider developing new ones based on analysis of the natural extracellular medium.