Autonomic control of blood pressure (BP) and heart rate (HR) was tested in offspring of rat dams that were unmanipulated (controls) or exposed repeatedly to either (1) Postnatal restraint, (2) Postnatal s.c. injections of alkaline saline, or (3) Prenatal s.c. alkaline saline. Under urethane anesthesia, BP was higher than control in 20-day-old offspring of restrained dams and lower at 80 days. The magnitude of the BP response to autonomic ganglionic blockade (chlorisondamine) changed in parallel; the control HR accelerator response was reversed at 20 days and enhanced at 80 days. Postnatal maternal injections increased BP in 20-day-old offspring and lowered it at 80 days. The BP response to blockade was unchanged; HR acceleration was attenuated at 20 days and increased at 80 days. No influence of Prenatal maternal injections was seen in adult offspring.
Conclusion: Post--not prenatal maternal stress disrupts BP and HR control in rat offspring; disruption is greater after restraint than injection. There is sympathetic hyperactivity in preweanlings and hypoactivity in adults.