A day in the life of a platelet.

P.K.Ghatak.MD

 No 1.

 

A young platelet is happily floating around in the bloodstream, then suddenly he is pushed into a narrow tunnel (capillary) the wall of which is neatly lined with closely fitted glazed tiles (endothelial cells). As the platelet is looking around, he noticed a part of the wall with missing tiles and blood is oozing out. Suddenly he sees his favorite face of collagen fiber with lips colored with von Willebrand factor. He feels compelled to give a kiss on her lips (receptor protein). But lo! Now he can't separate himself from her. His lips (receptors) are stuck on her lips. He notices his body shape is changing – swelling up, arms are coming out like arms of octopus and reaching out to other nearby platelets. As more and more platelets congregate and all the platelets are trying to kiss collagen lips, they form a heap and the mass completely covered up the missing tiles (break in endothelial surface). The platelet mass seals the leak and blood loss is prevented and a white soft clot is formed. From their bodies, granular packs burst open, and the chemicals spill all over. Now, an army of bridge-building-brigade assembles at the site in response to the released chemical (cytokines). Platelets release more chemicals containing construction materials (clotting factors fibrinogen, V, VIII, etc.). And the scaffolding takes the shape of a net. The net begins to trap RBCs and WBCs as they are traveling downstream with the blood flow. This is the beginning of the formation of a red but firm clot. As time passes the platelets release a clot stabilizing factor and that turns the red clot into a hard one, and this permanently seals the wound.

This story was told to us by one of our medical college professors as a metaphor. He took the story from the Mahabharata. It goes like this:

A student named Aruni approached the principal of a residential university and applied for university admission and requested his approval. Prof. Dhaumya told him that he would give him a test the following morning and then decide. Aruni faced Prof. Dhaumya in the early morning. To test Aruni's resolve and endurance he sent him out to his rice field. Aruni went to the field and found the monsoon rain flooded the rice paddocks. There he found one paddock was losing water fast due to a break in the mud embankment. Aruni immediately went into action. He dragged up earth from a nearby spot and began repairing the break. He tried and tried but the water continued to gush out, taking the newly reinforced mud wall with it. It was getting dark, and his work was far from over. He was tired and frustrated. In desperation, he laid his body across the breach of an embankment. That stopped the water leak, but as he attempted to leave the water began to flow out again. So, Aruni stayed in the field using his body to hold back water. When the professor noticed Aruni did not return, he called all the other students and went out to find him. It was a dark night; they could not see far. He began calling him.” Aruni where are you, answer me:” Finally, Aruni heard the professor's voice and replied.” Professor, I am here. In the field, lying here.” They came, and they were surprised to see him covered with mud and shivering in the cold. Aruni related the whole story. Professor told Aruni to get up and go to dormitory, and he took Aruni as his student.

We, all of us, knew Aruni's story from reading and rereading Mahabharata

At that time Mahabharata was our social media, television and internet all rolled into one. It is the story of sacrificing one's body for the common good. That is the purpose and objective of platelets.

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