Introduction
Microcirculation refers to the circulation of blood within the small blood vessels embedded in body organs. Microcirculation blood vessels consists of innervated vessels called arterioles on the arterial side of microcirculation and venules, which transport blood from capillaries to veins. These blood vessels have the function of distribution blood in tissues. The control of circulation in the microcirculation is under the control of two factors: Local control and the nervous system (Fung & Zwerfach, 2001).
The nervous system regulates microcirculation through sympathetic stimulation that involves hormones like nor epinephrine and epinephrine exerting their effect on smooth muscle. Local control mechanisms like inflammatory mediators, metabolic conditions and endothelium-produced compounds also control microcirculatory circulation. Regulation is achieved through the mediation of the level of contraction in smooth muscles that surround venules, arteries, arterioles and their junctions (Tuma & Walter, 2008).
The rate of microcirculation blood flow is regulated in the tissues through the contraction and dilation of the smooth muscles surrounding venules and arterioles. The law governing this relationship is Poiseuilles law that states that changes in the radius of a vessel has a very significant effect on the blood flow pressure. An Increase in the radius of a blood vessel results in a drop in blood flow rate and a fall in blood pressure. Vasoconstriction results in an increase in blood pressure and blood flow rate (Salerudi, 2011).
In this experiment, the effects of different chemicals were assessed for their consequences on the blood flow rate in the fin of a gold fish. Their effects were then recorded to illustrate their different ways these chemicals influence microcirculation.
Hypothesis
The null hypothesis that was formulated for this experiment was that Treatment of the fin of a fish with chemicals had a significant effect on blood flow rate. The Alternate hypothesis formulated for this experiment was that Treatment of the fin of a fish with chemicals has no effect on blood flow rate.
Materials and methodology
A makeshift platform was made in a cardboard box and a hole2 cm in diameter punched on it. The cardboard was then wrapped in saran wrap. A Goldfish was transferred from aquarium to troughs containing aquarium water for acclimatization 2 hours before the start of the experiment. The gold fish was then anesthetized using 400ml of Tricane methane sulfonate. After this treatment, the fish were then constantly washed with aquarium water to enhance its survival. Constant monitoring of the fish breathing movements was done to ensure survival of the fish.
The anesthetized fish was then put on a platform so that the fish tail was evenly spread on the hole of the platform. The fin of the fish was then observed under a microscope, under 100-x magnification through manipulation of card platform over the microscope stage. The fish fin was evaluated for cells, arteries, capillaries, and the rate of pulsation. Using a pasture pipette, a drop of wintergreen oil (1; 1000) dilutions was applied on the fish tail and the effect observed under the microscope in relation to control area of the fish fin.
After observation of the effect of the treatment was over, the excess wintergreen oil was removed via absorbent cotton and the fish tail flushed with Ringers solution and aquarium water. The experiment was then repeated with different chemicals, methylsalicate (1% solution), histamine(1:1000 solution), epinephrine 1: 1000 solution ,nor epinephrine(1:1000 solution), and nitroglycerine(1:20 solution), respectively. When the experiment was completed, the fish was euthanized through immersion in 250mg/l of tricane methane sulfonate (TMS) for 10 minute after which, the fish body was then frozen and incinerated.
Results
Chemical treatment with Wintergreen oil resulted in the Blood flowing faster than the normal blood flow rate in the fin of a fish. On the contrary, Nitroglycerine treatment resulted in the Blood flow rate flowing faster than the blood flow rate in wintergreen treatment.
Epinephrine treatment resulted in Slowing of the blood flow rate compared to the blood flow rate in wintergreen and nitroglycerine treatments.
Histamine treatment caused blood to flow faster than the blood flow rate in wintergreen oil and epinephrine treatment in the fin of the fish. Nor epinephrine treatment caused the Blood flow rate in the fin of the fish to flow faster than the blood flow rate in nitroglycerine treatment. Methysalicyte also caused the Blood flow rate in the fish fin to flow faster compared to the blood flow rate in histamine treatment
Conclusion
Discussion
However, not all the results obtained from this experiment were correct. Nor epinephrine causes peripheral vasoconstriction and a rise in blood pressure (Tuma & Walter, 2008). This effect was observed in the experiment. Epinephrine causes vasodilatation, a fall the pressure of blood and a reduction in the rate of flow of blood (Soldatov, 2012). This was also observed in the experiment. Histamine causes localized vasodilatation after injury of the body tissues resulting in a fall in blood pressure and slowing of blood flow rate (Soldatov, 2012) .The experiment recorded incorrect results because histamine caused vasoconstriction and an increase in blood flow rate in the experiment.
Wintergreen oil causes vasodilatation of blood vessels, decrease in blood pressure and an increase in blood flow rate (Salerudi, 2011). The results observed for Wintergreen oil were not correct. Nitroglycerine reduces blood flow by causing vasodilatation of blood vessels (Soldatov, 2012). The results obtained in the experiment for nitroglycerine were also not correct.
Methysalicylate causes vasodilatation and reduction in blood flow rate (Saldatov, 2012). This was not observed in the experiment. The results for methylsalicylate were wrong. There were many gross errors in the experiment, which can be traced to contamination of the chemicals used in the experiment. The accurateness of this experiment can be enhanced by careful consideration of every step in the experiment to minimize errors.
Fung C & Zweifach (2001)” Microcirculation mechanics of blood flow in capillaries” annual
Review of fluid Mechanics vol 3 189-210
NIH (2005). Regulation of blood flow in circulation. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/15804972
Salerudi G (2011). Circulation and its regulation. Retrieved from
Www.imt.liu.se/foutb/kurser/microcirc/pdf/mikro_2.pdf+control+of+microcirculation
Soldatov A. (2012).” Organ blood flow and vessels of microcirculatory bed in fish” Journal of
Evolutionary Biochemistry and physiology volume 42 .number 3. (243-252)
Tuma R. & Walter D. (2008) Handbook of physiology microcirculation. London: Academic
Press
