Endocrine changes induced by venipuncture in rhesus monkeys.

An animal-worn, remotely activated blood collection device was used to obtain estimates of baseline levels of testosterone (T), growth hormone (GH) and prolactin (PRL) from unrestrained and active male rhesus monkeys. As soon as possible after this baseline period, the males were captured and a final venipuncture sample was obtained. Venipuncture produced elevated GH levels compared to values obtained using the blood collection device, but was without detectable effect upon levels of T and PRL. Cortisol values, available only from a single animal, displayed an increase in response to venipuncture, much like that seen for GH.