The effects of capture and repeated venipuncture on serum levels of prolactin (Prl), growth hormone (GH) and cortisol (F) were assessed in outdoor, open compound-housed, socially-living female rhesus monkeys. In animals unaccustomed to capture, blood samples obtained soon after capture (time zero) contained relatively high concentrations of both Prl and GH (Prl>30 ng/ml, GH> 10 ng/ml) which declined dramatically over the next 60 min. Mean levels of serum Prl in capture-naive lactators (n=6) and non-lactators (n=5) were 83 ± 28 (sem) and 32 ± 11 ng/ml at time zero and fell significantly (P < 0.01) within 60 min to 28 ± 10 and 6 ± 2 ng/ml, respectively. GH levels in serum also decreased over time and the time-dependent reductions in serum Prl and GH were unaffected by intervening venipuncture or caging. In contrast, serum F rose after capture reaching peak values (330 – 515 ng/ml) 60 min later. The delayed rise in serum F could reflect the time required for pituitary trophic stimulation of the adrenals after capture. Capture-acclimated, lactating females displayed lower levels of Prl at time zero with values approximating those found at 90 min in the capture-naive group. Furthermore, capture-acclimated pregnant animals exhibited a significant rise in Prl levels after parturition in the spring. These studies suggest a non-specific, capture-related release of pituitary hormones in capture-naive, compound-housed female rhesus. However, animals that have been captured and bled repeatedly over some weeks or months show lower, physiological levels of Prl, indicating an acclimation to the procedure. Thus, outdoor-housed rhesus monkeys which have been acclimated to capture can be a useful model for studying the involvement of Prl in reproduction in this species.
No takes yet. Share an insight, caveat, or question.
Blank et al. (1983) studied this question.