Piperidine as a Normal Pressor Constituent of Human Urine

Summary. Normal human urine from non‐smokers contains piperidine up to 10 mg and more per litre, corresponding to a nicotine activity of about 0.5 mg per litre. After ether extraction and steam destillation the piperidine could be isolated as crystalline pitrate, as previously demonstrated for cow's urine (E uler , 1944). The pressor activity of ether extracts of normal human urine is chiefly due to piperidine as shown by a comparison of the biological action and the colorimetrically determined piperidine in urine extracts. Urine from horse, pig, cat and rabbit contains piperidine in similar amounts as in human urine.