Contents of microbicidal granules of leucocytes include all, EXCEPT:
**Core Concept**
The contents of microbicidal granules of leucocytes, particularly neutrophils, play a crucial role in defending against microbial infections. These granules contain various enzymes and antimicrobial peptides that help in eliminating pathogens.
**Why the Correct Answer is Right**
The correct answer is related to the components of microbicidal granules, which include defensins, lysozyme, and myeloperoxidase. These components work together to create a hostile environment for microbes, thereby preventing their growth and proliferation. Lysozyme, for instance, breaks down bacterial cell walls by hydrolyzing peptidoglycan, a component of the bacterial cell wall. Myeloperoxidase, on the other hand, generates hypochlorous acid, a potent antimicrobial agent that kills bacteria and other pathogens.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not typically included in the contents of microbicidal granules.
**Option B:** This option is incorrect as it is not a component of microbicidal granules.
**Option C:** This option is not a correct component of microbicidal granules.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the microbicidal granules of leucocytes are a crucial part of the innate immune response, helping to eliminate pathogens and prevent infections. Defensins, lysozyme, and myeloperoxidase are key components of these granules, and understanding their roles is vital for medical professionals.
**Correct Answer: D.**