Effect of chronic non-immunologically mediated bronchoconstriction on bronchial smooth muscle in the guinea pig.

Immature guinea pigs underwent eight weeks of methacholine-induced wheezing on a daily basis. At the end of the study the treated guinea pigs showed less of a weight gain than control animals. Relative dry tracheal weight was greater in the methacholine group than in controls. However, there were no differences noted on histologic examination of the lungs between the treated and control animals. Although experimentally induced amounts of bronchoconstriction may not be extrapolated to the same degree as seen in asthma, these findings suggest that repeated bronchoconstriction alone is not the cause of the smooth muscle hypertrophy and hyperplasia found in asthma.

Decreased absorption of propoxyphene by activated charcoal.

In 1968 we first suggested that activated charcoal (AC) should be administered in the emergency treatment of propoxyphene overdosage. The dramatic increase in recent years of deaths involving propoxyphene has prompted us to again evaluate the efficacy of AC in preventing absorption of propoxyphene from the GI tract. Male rats (100-125 g) were administered propoxyphene hydrochloride (P-HCl, 350 mg/kg) or propoxyphene napsylate (P-N, 825 mg/kg) either dissolved or suspended in 5% acacia in H2O. After 30 min the rats were administered either AC at 10 times the drug dose or water. Surviving rats were sacrificed at 1, 2, 4, 8, 12, and 24 h; the brain, liver, and both kidneys were removed intact, weighed, and stored at -70 degrees C. After lyophilization, the tissues were analyzed for propoxyphene and its metabolite, norpropoxyphene, by GLC. There were significantly less deaths in rats that received P-HCl + AC or P-N + AC than rats that received either P-HCl or P-N alone (9 vs 19, p less than .01 and 5 vs 10, p less than .05 respectively). Tissue levels of propoxyphene and norpropoxyphene were similarly significantly reduced. These studies provide further evidence of the efficacy of AC in propoxyphene overdosage.