Now consider a drug which is being constantly infused into a patient to establish a plasma concentration of 2mg/L. GFR in this patient is 150ml/min. The substance appears in the urine at a rate of 200μg/min. The substance is being filtered, and is not metabolised. What do we know about the handling of this substance in the nephron? Select 2 answers.
1. The substance must be reabsorbed.
2. The substance must not be reabsorbed.
3. We can't know from these data if the substance is being reabsorbed.
4. The substance must be secreted.
5.The substance must not be secreted.
6. We can't know from these data if the substance is being secreted.