A preliminary description of responses of free-ranging rhesus monkeys to brief capture experiences: Behavior, endocrine, immune, and health relationships

A cohort of free-ranging rhesus monkeys has been followed since birth in 19 93 on the island of Cayo Santiago, Puerto Rico. At 3 years of age, subjects were trapped and blood samples were collected after capture and prior to r elease the following day. Blood samples were processed for natural cytotoxi city toward xenogeneic tumors, phenotyping, and plasma hormones. Intestinal parasites were determined from fresh stool samples collected during trappi ng. Data were also available from the previous year for antibody titers to latent viruses prevalent in this population. Behavioral traits of each monk ey were characterized using a previously developed trait scale for rhesus m onkeys. Natural cytotoxicity toward both K563 and Raji targets declined fro m capture until release the following day. Plasma cortisol rose and plasma prolactin and growth hormone fell during the period of captivity; a rise in insulin was significant. It was expected that individual differences in be havioral traits might predict immune and hormone levels at the time of capt ure or changes in these parameters during the capture period. Although beha vioral adjectives tended to cluster along three orthogonal dimensions (Inse curity, Irritability, and Sociability), they bore no relationship to the ph ysiological parameters collected acutely (in vitro immune and endocrine par ameters). The individual difference markers of Sender and maternal rank wer e not related to the magnitude of the observed changes in these in vitro pa rameters, either. However, an in vivo measure (CMV titer) was related to in dividual differences in Irritability. It was concluded that the magnitude o f the stress associated with capture overwhelmed the individual difference effects. (C) 1999 Academic Press.