Β-Glucuronidase ACTIVITY AFTER THYRO-PARATHYROIDECTOMY IN RATS

Abstract

\g=b\-Glucuronidaseactivity was followed in the liver, spleen, thymus, adrenals, kidneys and submaxillary glands of the rat during the atrophy of these organs caused by thyro-parathyroidectomy. The atrophy is not related, except in the case of the liver, to deficient food intake.\g=b\-Glucuronidaseactivity per unit weight of tissue was found to be increased in almost all the organs examined in correlation with the period of fastest loss in weight: when the rate of weight loss decreased or was reduced to nil, the enzyme levels showed a tendency to return to normal values.The significance of these data is discussed.It has recently been observed that atrophy of the spleen, thymus gland and lymph nodes produced by starvation [Pedegrino & Vdlani, 1956] or X-rays [Pellegrino & Villani, in preparation] is accompanied by a two-or three-fold increase in /3-glucuroni¬ dase activity. On the other hand, it has been known for a long time [Hammett, 1923a and 6] that in thyro-parathyroidectomized rats the weight of the liver, spleen, thymus gland, ovaries, testes, adrenals, pancreas and kidneys is markedly decreased. It was therefore considered interesting to discover whether a correlation existed between atrophy and /3-glucuronidase increase in the organs of such animals. METHODSForty-five virgin female albino rats of the Italico strain bred in this department and weighing about 150 g each were used. The animals were kept on a standard balanced diet [Random & Causeret, 1947], supplemented with green vegetables. Two types of experiments were performed. In the first, the animals were fed ad lib., in the second, paired-feeding was used. The thyro-parathyroidectomized rats ate on the average 10 g of food dady. Thyro-parathyroidectomy was performed under light ether anaesthesia and all the animals were allowed free access to 0-5 % CaCl2 solution in tap water during the experimental periods.The rats were killed by exsanguination under light ether anaesthesia 5, 9, 15 or 30 days after the operation. The completeness of the operation was checked at necropsy and rats with symptoms of wound infection were discarded. The thymus gland, submaxillary glands, liver, spleen, kidneys and adrenals were dissected, freed of connec¬ tive tissue, and weighed on a torsion balance to the nearest mg. A small portion of each organ was weighed and suspended in distilled water (adjusted to pH 7-4) with a glass homogenizer [Potter & Elvehjem, 1936] kept in cracked ice. The final dilution of the suspensions was 1:200 (w/v). They were stored in the cold room at 2°C and were always used within 6 hr of preparation.