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A research on the effects of ibuprofen on the heart rate of the daphnia

Investigating factors affecting the heart rate of Daphnia Class practical In the water flea Daphnia, the single, small heart is easily visible when viewed under transmitted light under a low power microscope. The heart rate which can be up to beats per minute can be monitored and counted in different conditions — for example changing water temperature, or changing the type and concentration of chemicals added to the water.

A change in Daphnia heart rate may not be a predictor of a similar change in human or vertebrate heart rate under the same conditions, but the procedure provides an interesting technique for investigating the effects of different chemicals on a metabolic process. Thanks to the British Pharmacological Society for providing the teaching notes on this practical. With modifications made by Prof Richard Handy, University of Plymouth Lesson organisation This will depend on access to a healthy culture of Daphnia and on the number of microscopes you have.

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Students can readily follow this procedure working in pairs. Because of the variability of results between individual Daphnia, it is not appropriate to draw conclusions from one set of results; each pair or group of students should carry out more than one investigation to contribute to the class set.

  1. Along with most of their lab equipment including. It was Similar Essays How Caffeine Affects The Heart Rate Of Daphnia words - 5 pages IntroductionThe purpose of this experiment is to determine whether or not caffeine has an affect on the heart rate of DaphniaHypothesisThe Daphnia heart rate will increase with the concentration of caffeine.
  2. Refer to Hazcard 3C Each compound will have different hazards and associated risk control measures.
  3. However, there are currently no chronic IB toxicity data on arthropod populations, and the aquatic life impacts of such analgesic drugs are still undefined. One of the ways adrenaline increases heart rate is through the action of what is known as a 'second messenger' or 'transduction component', in this case it is a chemical made in the cell known as cyclic adenosine monophosphate cAMP.

One option is to record a live video of a sample Daphnia, during a time period in which students count the heart beats. Then you replay the video in slow motion and count the heart beats again. This allows students to consider the accuracy of their counting. If your time or access to chemicals is limited, you could allow the students to work through the procedure in order to evaluate it and then use the example results provided for analysis.

Apparatus and Chemicals For each group of students: With pond water culture, or other sources of food, more careful hygiene precautions are necessary. You will find more details in section L Daphnia are crustaceans, commonly found in ponds and lakes and widely sold as live fish food. These animals are fascinating objects for observation and study in their own right. They feed by filtering minute particles such as bacteria and algae, from the fresh water in which they live.

Daphnia can be kept in any watertight container containing tap water that has been allowed to stand for a few days. Keeping a few Daphnia is not difficult, but cultivating a vigorous, dense colony requires some care. A good supply of oxygen is necessary, either by aeration or by using a large shallow tank to ensure that a large surface area of water is exposed to the air.

You can purchase live cultures from suppliers, including pet shops and local aquarists. Some scientific suppliers sell viable dried Daphnia eggs and culture kits. Stock purchased from aquarists is usually free from this hazard.

The safest, most hygienic and most convenient ways to provide the necessary food for a colony of Daphnia is to feed them on a few drops of a suspension of fresh yeast or of egg-yolk medium made by blending a hard-boiled egg in cm3 of water. Alternatively, you can buy food such as Liquifry No 1 or Spirulina powder from aquarists or scientific suppliers.

Small, regular supplies of food are required. Provide only sufficient to cause the water to turn faintly cloudy. After a few days the Daphnia will have filtered out the suspended particles of food, making the water clear once more, which is your cue to add more food.

  • After a few days the Daphnia will have filtered out the suspended particles of food, making the water clear once more, which is your cue to add more food;
  • Alternatively, you can buy food such as Liquifry No 1 or Spirulina powder from aquarists or scientific suppliers;
  • This is the ratio of the rate of activity at one temperature to its rate at a temperature 10 degrees higher;
  • Then cAMP levels increase and this increases the electrical activity of the sinoatrial node, making it depolarize and 'beat' faster;
  • We will use a digital heart rate monitor strapped on our chest while we perform different levels of exercise;
  • Then cAMP levels increase and this increases the electrical activity of the sinoatrial node, making it depolarize and 'beat' faster.

Clear scum from the surface of the water; but leave debris that sinks to the bottom — it may contain Daphnia eggs. An additional, larger dish outside the small one could also be filled with water at the appropriate temperature to help reduce heat loss from the experimental chamber.

Refer to Hazcard 3C Each compound will have different hazards and associated risk control measures. Acetylcholine is an irritant to eyes, respiratory system and skin and is used at a concentration of 1 g in cm3 of water. L-adrenaline epinephrine is toxic by inhalation, in contact with the skin and if swallowed.

Used by students at a concentration of 1 g in cm3 of water it is low hazard. Caffeine is harmful if swallowed! In each case, add one drop to 5 cm3 of water before applying to the Daphnia. When working with organisms under a microscope, the effects of heating due to the microscope lamp itself can be significant. Turning the lamp on only when observing the Daphnia will help, and LED microscopes produce less heat than those with incandescent lamps. Ethical issues Teachers should be careful to introduce these animals in a way that promotes a good ethical attitude towards them and not a simply instrumental one.

Although they are simple organisms that may not 'suffer' in the same way as higher animals, they still deserve respect. Animals should be returned promptly to the holding tank after being examined. This supports ethical approaches that are appropriate to field work where pond animals are returned to their habitat after observations have been made.

Procedure Take care handling any chemicals that might affect the heart rate of Daphnia. Observe normal, good laboratory hygiene practices when completing the practical. Preparation a Take a small piece of cotton wool, tease it out and place it in the middle of a small Petri dish. The beating heart is located on the dorsal side just above the gut and in front of the brood pouch see diagram. Make sure that you are counting the heart beats, and not the flapping of the gills or movements of the gut.

The heart must be observed with transmitted light if it is to be properly visible. The heart beat of Daphnia is very rapid, so count the beats by making dots on a piece of paper in the shape of a letter S.

Count the dots and express heart rate as number of beats per minute. Investigating the effect of temperature g Record the temperature of the water in the Petri dish. Allow the Daphnia some time to acclimatise, but keep a check on the temperature of the water in the dish and add more hot or cool pond water if necessary to adjust the temperature.

Investigating the effect of chemicals k Take a large Daphnia from the stock culture and record its heart beat at room temperature in pond water as in step e. Draw the pond water off the Daphnia with a pipette and replace it with 2 or 3 cm3 of the water containing ethanol Note a research on the effects of ibuprofen on the heart rate of the daphnia. Record the rate of heart beat again. Teaching notes Daphnia is poikilothermic, which means that its body temperature and therefore its metabolic rate are affected directly by the temperature of the environment.

The change in metabolic rate is reflected in the rate at which the heart beats cardiac frequency. The effect of temperature on a metabolic activity may be expressed in terms of the temperature coefficient Q This is the ratio of the rate of activity at one temperature to its rate at a temperature 10 degrees higher.

There will be considerable variation in the data gathered. Class results for the heart beat at any temperature should be recorded and mean results and standard deviation calculated. Student notes Example results: In humans and many other animals, heart rate is slowed by the parasympathetic nervous system neurotransmitter: This occurs after feeding, during sleep, and during breath-holding and swimming underwater. A slowed heart rate and the associated fall in the rate of ejection of blood from the heart is sufficient to maintain body function during rest, and conserves energy in the heart under conditions where its supply and the supply of oxygen in the blood are diminished.

In contrast, heart rate is increased by the sympathetic nervous system neurotransmitter: A research on the effects of ibuprofen on the heart rate of the daphnia occurs during exercise or fear. The effect is to increase the rate of ejection of blood by the heart. This means that there will be more blood flow to skeletal muscle in which exercise causes dilatation of blood vesselsso the skeletal muscle cells are supplied with more oxygen and respiratory substrates used to generate energy in respiration where it is needed.

A drug that increases heart rate is called a positive chronotrope, and this is demonstrated in this experiment when adrenaline is used to increase heart rate in Daphnia. One of the ways adrenaline increases heart rate is through the action of what is known as a 'second messenger' or 'transduction component', in this case it is a chemical made in the cell known as cyclic adenosine monophosphate cAMP.

Transduction is the process that follows the action of a drug, hormone or neurotransmitter at a receptor.

Thus, when adrenaline activates the beta-1 adrenoceptor in the sinoatrial node, this leads to an increase in cAMP in the sinoatrial node and the result is an increase in heart rate.

  • Small, regular supplies of food are required;
  • When Daphnia is exposed to Nicotine and Ibuprofen, the heart rate of the daphnia could not be seen as any different;
  • In contrast, heart rate is increased by the sympathetic nervous system neurotransmitter:

Caffeine mimics some of the effects of adrenaline and noradrenaline in the heart. By a different mechanism not involving beta-1 adrenoceptors, caffeine also increases the amount of cAMP in the sinoatrial node. Then cAMP levels increase and this increases the electrical activity of the sinoatrial node, making it depolarize and 'beat' faster.

Caffeine has additional effects on the heart. Like adrenaline and noradrenaline, it can affect the main pumping chambers ventriclesleading to an increase in the rate of contraction and relaxation of each heart beat. This means that, as well as beating faster, the heart's individual beats are associated with an increased volume of blood ejected into the circulation per unit time.

This is called increasing cardiac output. Ethanol slows heart rate.

Investigating factors affecting the heart rate of Daphnia

At the concentrations used in this experiment, ethanol depresses the nervous system by acting as what is known as a non-selective neurodepressant. The amounts of ethanol necessary to achieve this effect in humans would also be sufficient to depress the respiratory centres of the brain, rather like the effect of an overdose of general anaesthetic, resulting in death. Aspirin has no effect on heart rate.

Despite this, aspirin has beneficial effects in the heart. By reducing the ability of platelets to adhere to damaged blood vessel walls, aspirin reduces the chance of coronary artery thrombosis, the event that precipitates a heart attack.

People who are take aspirin long-term for medical reasons because they have cardiovascular disease or diabetes may have a lower heart rate than controls, simply because they experience less coronary and peripheral thrombosis and thus have a better lubricated cardiovascular system.

In terms of heart rate, the Daphnia sinoatrial node is actually a collection of spontaneously active nerves in a body called the cardiac ganglion. This means that it would be risky to extrapolate heart rate findings from Daphnia directly to humans without first validating the model. Model validation requires examination of a range of positive and negative controls for their effects in the model.

To achieve this, the type and extent of the effect in humans at the same drug concentration the human template must be known. It is not always possible to obtain such a human template; this is why the outcome of a novel non-human experimental study is of only provisional clinical relevance.

Proof of model validity emerges only once human data sets are available.