Recurrent postpartum anaphylaxis with breast-feeding.

BACKGROUND: Anaphylaxis associated with breast-feeding is a rare but potentially life-threatening event. CASE: This woman reported anaphylaxis with three previous pregnancies while breast-feeding. With her fourth pregnancy she was treated with corticosteroids and antihistamines after delivery. Despite treatment, she developed urticaria, facial edema, and throat tightening, less severe than prior episodes. Her symptoms resolved with epinephrine and antihistamine but recurred with subsequent breast-feeding. On postpartum day 4 she had no symptoms while breast-feeding. CONCLUSION: Three cases of postpartum breast-feeding anaphylaxis have been reported. Although the pathophysiology is unclear, it may involve the decrease in progesterone and rise of prolactin causing mast cell degranulation. Avoidance of nonsteroidal antiinflammatories and prophylaxis with corticosteroids and antihistamines may offer the best protection.

An in vivo rat model for assessment of extrahepatic metabolism.

INTRODUCTION: Xenobiotic metabolism in extrahepatic tissues has been extensively studied in vitro, but it is difficult to estimate in vivo the share of xenobiotic transformation in extrahepatic tissues for lack of a suitable approach. In this paper an in vivo rat model for assessment of extrahepatic metabolism is described, and the model was investigated using the conversion of lidocaine to monoethylglycinexylidide (MEGX). METHODS: The rats were anesthetized with ethyl ether inhalation. The liver was exposed, the liver artery ligated, and the portal vein was clamped at its distal end. The left hepatic lobe was partly excised along its inferior margin, and a heparinized silicone catheter, diameter 0.2 cm, was inserted into the portal and left hepatic veins to allow the recirculation of portal vein blood. A sham operation was performed in the control group. RESULTS: Phenol red test showed that hepatic blood supply was absolutely blocked in model rats. At 30 min after establishing the portal-cavum bypass, the renal function and electrolytes did not change, but serum glucose decreased by 64.4 +/- 30.4%; 30 min after intravenous administration of 1.0% lidocaine 2 mg x kg(-1), serum MEGX in model rats was 32.0 +/- 7.14% of that in the control group, which mostly existed in a free form and was not induced by phenobarbital pretreatment. DISCUSSION: The model is easy to establish and provides an in vivo method to study the extrahepatic metabolism of xenobiotics.