This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Which of the following is responsible for housekeeping functions? \nSelect and explain. \nA. COX1, B. COX2, C. COX3, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cox-1 are constitutive (always present in cells) , serve housekeeping function.\nCyclooxygenase\xa0 pathway:\xa0 All\xa0eicosanoids\xa0with\xa0ring\xa0structures (that\xa0is,\xa0the\xa0prostaglandins,\xa0thromboxanes,\xa0and\xa0prostacyclins) are\xa0synthesized\xa0via\xa0the\xa0cyclooxygenase\xa0pathway.\xa0Two\xa0related isoforms\xa0 of\xa0the\xa0cyclooxygenase\xa0enzymes\xa0have\xa0been\xa0described. \u200b\nCyclooxygenase-1 (COX-1) is responsible for the physiologic production of prostanoids, whereas cyclooxygenase-2 (COX-2) causes the elevated production of prostanoids that occurs in sites of chronic disease\xa0and\xa0inflammation. \u200b\nCOX-1\xa0is\xa0a\xa0constitutive\xa0enzyme\xa0that regulates normal cellular processes, such as gastric cytoprotection, vascular homeostasis, platelet aggregation, and reproductive and kidney functions. COX-2 is constitutively expressed in tissues such as the brain, kidney, and bone. Its expression at other sites is increased during states of chronic inflammation.\u200b\nDifferences in binding\xa0site\xa0shape\xa0have\xa0permitted\xa0the development\xa0of\xa0selective COX-2 inhibitors.\u200b\nAnother distinguishing characteristic\xa0of\xa0 COX-2\xa0 is\xa0that\xa0its\xa0expression\xa0is\xa0induced\xa0by\xa0inflammatory mediators like TNF-α and IL-1 but can also be pharmacologically inhibited by glucocorticoids, which may contribute to the significant anti-inflammatory effects of these drugs.\u200b\nReference: Lippincott Illustrated Reviews: Pharmacology, Wolters Kluwer Sixth Edition page no 448\u200b', 'role': 'assistant'}]