Morphometric evaluation of acinar cell number and volume in rat pancreas treated with dl-ethionine

1. The morphological changes of the pancreas induced by administration of dl-eyhionine were determined for treated rats and for a group of pair-fed untreated controls in order to separate the direct effect of dl-ethionine from the effect of accompanying reduction of food intake. 2. Adult male Wistar rats were studied in 3 groups of 10 animals each: 1) fed ad libitum and treated daily with dl-ethionine (35 mg/100 g body weight, ip) for 10 days; 2) treated daily with vehicle (saline) as group 1 and pair-fed to group 1; 3) treated daily with vehicle (saline) and fed ad libitum. Two rats from each group were killed on days 2, 4, 6, 8 and 10 to characterize the ancreas in terms of morphological properties using morphometric analysis. 3. Exposure to del-ethionine induced a progressive and significant decrease in both pancreas weight and acinar cell number and volume. Pair feeding induced less pronounced decreases in pancreas weight and acinar cell volume. Pancreas weight was 125 mg/100g body weight for dl-ethionine-treated vs 205mg/100g body weight for pair-fed controls and 320 mg/100 g body weight for ad libitum-fed controls after 10 days. Acinar cell number (x ñ o-/Vn): 175 x 10**6 ñ 28.4 per µm3 for dl-ethionine-treated vs 221 x 10**6 ñ 17.3 per µm3 for pair-fed controls and 271 x 10**6 ñ 23.9 per µm3 for ad libitum-fed controls. Acinar cell volume (x ñ o-/Vn) was 1292 ñ 65.4 µm3 for dl-ethionine-treated vs 1436 ñ 74.9 µm3 for pair-fed controls and 1758 ñ 117.1 µm3 for ad libitum-fed controls. 4. Continuous treatment with dl-ethionine for 10 days induced pancreatic weight loss for two main reasons: 1) reduction of the number of acinar cells, an effect apparently induced by dl-ethionine administration, and 2) acinar cell atrophy consequent to food restriction

Açäo de sais de cobre sobre a xantina desidrogenase na carcinogênese hepática de ratas / Action of copper salts on xanthine dehydrogenase in hepatic carcinogenesis of rats

Estudou-se a inibiçäo da atividade de xantina desidrogenase (XD) do soro de ratas pelo acetado de cobre (AcCu). Verificou-se também a relaçäo entre a atividade XD e a degeneraçäo hepática e carcinogênese pela D-L-etionina. Experiências mostraram que a AcCu é um potente inibidor da XD e que esta inibiçäo é näo-competitiva quando se mantém constante a concentraçäo do receptor de eletrons, e do tipo competitivo quando esta concentraçäo varia permanecendo constante a concentraçäo de substrato. Comparando-se estes estudos com os resultados da dosagem da atividade de xantina oxidase (oxigênio como receptor de eletrons) sugere-se que radicais estariam, envolvidos na açäo citotóxica do complexo AcCu-etionina com provável necessidade de ocorrência de uma reaçäo de reduçäo