The effect of protein or energy restriction on the biodistribution of Na99TcmO4 in Wistar rats

Abstract

The effect of malnutrition on the biodistribution of radiopharmaceuticals is not known. We studied the biodistribution of 99Tcm-labelled sodium pertechnetate (Na99TcmO4) in two rat models of malnutrition. Three groups of 2-month-old rats were separated according to their diets: (1) control diet, 23% protein (C); (2) protein-restricted, receiving 8% protein (PR), both ad libitum; and (3) energy-restricted, receiving 60% of control diet (ER). After 21 days of the diet, 99Tcm was injected and the animals were killed after 30 min. The organs were isolated, their weight determined and the absolute per cent (%ID) and the per cent per gram injected dose (%ID x g(-1)) calculated. The %ID and %ID x g(-1) had a similar pattern, increasing in stomach and brain and decreasing in the thyroid, but did not change significantly in kidney, lung, liver, bone or testis in PR rats, except in the heart where the increase was only observed in the %ID x g(-1). In the ER group the %ID x g(-1) was decreased in the bone only, and did not change in the other organs. It is suggested that when using Na99TcmO4 scintigraphy in malnourished patients, the different patterns of distribution must be kept in mind.

Metabolic programming of ovarian angiogenesis and folliculogenesis by maternal malnutrition during lactation

“…In rodents, the primordial follicles are formed by day 3 of age, and the first wave of follicles develops into antral follicles over the next 3 weeks (64)(65)(66). In agreement with the literature (55,67,68), our study showed that during this period, the PER group presents significant alterations in body weight. In addition, thyroid function and milk composition are altered at this time (55,67,68).…”

“…Epidemiological data and studies in animals have focused on the concept of metabolic programming, which specifies that the quantity and quality of nutrition in the perinatal period generate consequences in adulthood (45,51,53,55,60). Restricting food during the perinatal period is associated with a reduction in growth rate.…”

“…The PER group, in spite of having free access to diet, consumed about 60% of that consumed by the control group (55). The protein-restricted diet was prepared at our laboratory by using the control diet (Nuvilab-Nuvital Ltd., Paran a, Brazil), with the replacement of part of its protein content with cornstarch.…”

Biodistribution of the radiopharmaceutical sodium pertechnetate after biliopancreatic bypass with a duodenal switch

“…The reduction in the %ATI/g in thyroid can be related to the postoperative energy deficiency, knowing that half of the small bowel is defunccionalyzed and the stomach is highly reduced. Steps et al had attributed this phenomenon to a reduction of the transport of sodium pertechnetate to the thyroid gland, as happen with iodine in malnourished patients (Passos et al, 2000;Passos et al, 2002). Further studies are necessary to explain these findings.…”

Aqueous extract of the medicinal plant Mentha crispa alters the biodistribution of the radiopharmaceutical sodium pertechnetate in Wistar rats

“…The interaction of drugs with radiobiocomplexes has also been studied, with both positive and negative results (Owunwanne et al, 1995). Passos et al (2000; have also demonstrated that dietary conditions can interfere with the biodistribution of radiobiocomplex. Several authors have also reported that, due to their pharmacological properties, some chemical compounds can alter the biodistribution of various radiobiocomplexes (Brito et al, 1998;Diré et al, 2003;Gomes et al, 2002;Diré et al, 2001;Grigoleit and Grigoleit, 2005;Hesslewood and Leung, 1994;Aguiar et al, 2002;Gomes et al, 2001;Mattos et al, 1999;Mattos et al, 2001).…”