Given the task definition and input, reply with output. In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

Following replicate control measurements , test ramps were repeated in the presence of sodium nitroprusside ( 1 microM ) and phentolamine ( 1 microM ) to eliminate potential smooth muscle and alpha 1 - adrenoceptor effects , respectively .
alpha 1