| Pi | parental generation; pressure in inspiration; protease inhibitor |
|---|---|
| PKI | potato kallikrein inhibitor |
| PRI | Pain Rating Index; phosphate reabsorption index; phosphoribose isomerase; placental ribonuclease inh... |
| PSI | posterior sagittal index; problem solving information; prostaglandin synthetic inhibitor; psychologi... |
| PSTI | pancreatic secretory trypsin inhibitor |