Effects of three plant growth regulators on the immune response of young and aged deer mice Peromyscus maniculatus.

Abstract

Male and female deer mice (Peromyscus maniculatus) over 2 years old and female mice less than 1 year old were fed chlorocholine chloride (CCC, 40 mg/kg mouse/day) or glyphosine (GPS, 30 mg/kg mouse/day) to test if the effects of these compounds on selected immune responses differed by age and sex. Venezuelan equine encephalitis virus (VEEV) and Modoc virus (MODV) were inoculated into other mice at day 23, both separately and in combination, to observe age-related toxicant-induced changes in mortality. Gibberellic acid (GA), daminozide (DAZ), and GPS also were fed to mice to examine their effects on viremia and antibody patterns following challenge with VEEV, MODV, or Pichinde (PICHV) viruses. Age and sex of mice influenced several measured immune parameters regardless of type of feed consumed, GPS and CCC also affected some immune functions, but the effects were similar for all age and sex groups except for final body weight which decreased only for old females fed GPS and lymphocyte viability which decreased only in young females fed CCC. Increases in mortality following VEEV infection of GPS-fed mice were the same in all mice but old females had a shorter time until death (4 days) than old males (9 days) or young females (7.5 days). CCC increased mortality three times more in old and young females than in young males. No mortality occurred in mice inoculated with MODV alone. An apparent interactive effect occurred between VEEV and MODV decreasing percent mortality below that caused by VEEV alone and reducing CF antibody titers to MODV. The toxicants also significantly increased mortality following