Sherry E. Rier

Endometriosis in rhesus monkeys (Macaca mulatta) following chronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The incidence of the reproductive disease endometriosis was determined in a colony of rhesus monkeys chronically exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin) for a period of 4 years. Ten years after termination of dioxin treatment, the presence of endometriosis was documented by surgical laparoscopy and the severity of disease was assessed. The incidence of endometriosis was directly correlated with dioxin exposure and the severity of disease was dependent upon the dose administered (p < 0.001). Three of 7 animals exposed to 5 ppt dioxin (43%) and 5 of 7 animals exposed to 25 ppt dioxin (71%) had moderate to severe endometriosis. In contrast, the frequency of disease in the control group was 33%, similar to an overall prevalence of 30% in 304 rhesus monkeys housed at The Harlow Primate Center with no dioxin exposure. This 15-year study indicates that latent female reproductive abnormalities may be associated with dioxin exposure in the rhesus. Therefore, the effects of this toxin may be more diverse than previously recognized.

Human recombinant interferon alpha inhibits naloxone binding to rat brain membranes.

Regulation of certain central nervous system (CNS) functions by the immune system may involve interferons (IFNs) acting through opioid receptors. Human recombinant interferon alpha (hrIFN alpha), as well as natural IFN alpha, have been reported to modulate a variety of physiological CNS functions both in vivo and in vitro. If the mechanism is via opioid receptors then IFN alpha should inhibit the binding of certain opioid radioligands to brain membranes. This study reports the inhibitory effect of hrIFN alpha on the binding of 3H-naloxone to rat brain membranes in vitro. The inhibitory effect at 37 degrees C is hrIFN alpha concentration dependent over the range of 500 to 6000 antiviral units per ml (U/ml) with 500 micrograms of membrane protein. The presence of NaCl (100mM) increases specific binding of naloxone and attenuates the inhibitory effect of hrIFN alpha. The inhibitory effect of hrIFN alpha is sensitive to temperature with maximum inhibition observed at 37 degrees C, and less as incubation temperature is reduced. These data suggest that IFN alpha may modulate certain physiologic functions via opioid pathways in the brain.