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Biomedical subjects

K D Trick

Publications and source records attributed to K D Trick.

12 recordsLinked to original sources
PubMed1994

Changes in pancreatic glutathione peroxidase and superoxide dismutase activities in the prediabetic diabetes-prone BB rat.

Pancreatic superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities were measured during the development of diabetes in diabetes-prone BB rats (BBdp) prior to insulin dependence. The pancreata from seven to eight BBdp rats of each sex were examined at ages 5, 7, 10, and 18 weeks and compared with age-matched control BB rats (BBc). At Week 18, BBdp rats had moderate to high insulitis but normal levels of blood glucose and insulin. Pancreatic CuZnSOD activity in BBdp rats was two times higher than the activity seen in BBc rats at age 5-10 weeks but then declined to the same level as seen in BBc rats at 18 weeks of age. MnSOD activity increased over time in the BBdp rats but remained very low in BBc rats. These changes in CuZnSOD and MnSOD activity resulted in BBdp rats having twice the pancreatic total SOD activity compared with BBc rats (P < 0.0001). Total GSHPx activity was significantly reduced in the pancreata from both male and female BBdp rats compared with their respective controls (P < 0.01 and P < 0.0001, respectively). The lower total GSHPx activity was due to reduced selenium-dependent GSHPx (SeGSHPx) activity. Erythrocyte and plasma activity of these enzymes was not different between rats with or without insulitis, indicating that differences in enzyme activities were confined to the pancreas. Thus, changes in pancreatic antioxidant enzyme activities occur prior to the development of diabetes symptoms in BBdp rats and may be related to the destruction of the pancreatic B cells and ultimate development of diabetes.

Animals↗
PubMed1991

Dietary (n-3) fatty acids affect rat heart, liver and aorta protective enzyme activities and lipid peroxidation.

In a 16-wk study, weanling Wistar rats (32 males and 32 females) were fed a modified AIN-76 diet containing 20% fat with various (n-3) fatty acids. All dietary fats provided the same amount of saturates, monounsaturates, and total essential fatty acids [(n-6) + (n-3)]. The control diet contained lard/corn oil (L/CO). The other diets contained (n-3) fatty acids from linseed oil (LSO), from linseed oil + menhaden oil (LSO + MO) or from menhaden oil (MO). The (n-3) diets reduced total and HDL-cholesterol, particularly in rats fed the MO diet. Platelet thromboxane levels were equally depressed by the LSO and MO diets. Dietary (n-3) fatty acids significantly elevated docosahexaenoic acid in livers and hearts of male and female rats, with females reaching higher levels. This increase was accompanied by reduced arachidonic acid, except for hearts of females in which the major decrease was in linoleic acid. Overall, enzyme activities in the MO-fed group were decreased to the following levels (relative to the activity in the control group): heart Mn superoxide dismutase (SOD), 28%; liver CuZnSOD, 82%; aorta CuZnSOD, 32%. Greater reductions in these enzyme activities were seen in the female rats fed the MO diet compared with male rats. Lipid peroxidation, assessed by urinary, heart and liver thiobarbituric acid reactants, was increased by dietary (n-3) fatty acids (MO greater than LSO + MO greater than LSO greater than L/CO) and was higher in females than in males. These results indicate that enhanced lipid peroxidation occurs with the increased oxidative stress of elevated tissue (n-3) fatty acids accompanied by reduced SOD activity.

Animals↗
PubMed1985

Diet can prevent diabetes in the BB rat.

When compared with laboratory chow, a defined, semipurified diet prevented diabetes, reduced the frequency of insulitis, increased thymus weight and total white blood cell count, and doubled thymus T-helper/T-suppressor cell ratios in diabetes-prone BB rats. These data show that the diabetic syndrome in BB rats may be prevented or delayed by changes in diet, which may occur through alteration of pathogenic defects in the immune system.

Animals↗
PubMed1984

Increased plasma and tissue levels of vitamin E in the spontaneously diabetic BB rat.

Increased plasma and tissue levels of vitamin E were found in spontaneously diabetic BB rats (D) as well as asymptomatic/diabetes-prone BB rats (AD) in comparison to levels in non-diabetic control rats (ND). Treatment of D rats with insulin for 30 days returned plasma and tissue values of vitamin E to control levels. The changes reported here could not be explained solely on the basis of variations in total lipid content of plasma. These data suggest the metabolism of vitamin E is altered in asymptomatic and spontaneously diabetic BB rats and this alteration returns to control values following insulin treatment. Furthermore, it might be speculated that these data indicate a relationship between vitamin E and insulin.

Animals↗
PubMed1984

Serum enzymes in the BB rat before and after onset of the overt diabetic syndrome.

As part of a six-month prospective study of the effects of neonatal thymectomy in the spontaneously diabetic BB Wistar rat, activities of the following enzymes were determined: alkaline phosphatase (AP), lactate dehydrogenase (LDH), creatine phosphokinase (CPK), glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and UDP-galactosyltransferase (UDPG). In prediabetics, AP and LDH levels were higher than in sham-operated, non-diabetic controls; however, this increase was seen in nearly all diabetes-prone BB rats, diminishing the usefulness of these changes in discerning potential diabetics from asymptomatic, diabetes-prone rats. After onset of the syndrome, there was a striking elevation of AP values in all diabetics with no similar alteration in asymptomatic, diabetes-prone rats suggesting this was a diabetes-related phenomenon. By contrast, UDPG was the only enzyme to decrease immediately following the onset of the syndrome. Both UDPG and AP levels correlated with blood glucose, the former negatively and the latter positively, suggesting a close relationship with changes occurring after onset of the syndrome. The remaining enzymes increased only in a portion of diabetics alone (GOT, GPT) or in a portion of both diabetics and asymptomatic, diabetes-prone BB rats (LDH, CPK).

Alanine Transaminase↗
PubMed1984

Time course of serum glucoregulatory variables and lipids following neonatal thymectomy of diabetes-prone and control BB Wistar rats fed a defined diet.

The acute diabetic syndrome in the BB Wistar rat resembles human type 1 (insulin-dependent) diabetes, including a possible association with T cell-mediated, (auto)immune processes. In most previous studies 'normoglycemic' littermates of diabetic BB rats have been used as controls and little attention has been paid to the role of diet. It now appears that asymptomatic/diabetes-prone littermates of diabetics have immune system defects as well as metabolic abnormalities. Since there are also indicators that the disease process starts before animals become symptomatic, we looked for prospective metabolic changes in prediabetic, asymptomatic/diabetes-prone and control (diabetes-free) BB rats following intervention in the immune system while maintaining the animals on a defined diet (AIN-76). The results reported here confirm and extend the finding of Like et al. (1982) that neonatal thymectomy reduces the frequency of the syndrome and emphasize the role of diet in modifying its expression. In contrast to previous reports of hyperglucagonemia only after onset of diabetes, asymptomatic/diabetes-prone animals had periodic increases of plasma glucagon values up to 3-fold those of diabetes-free controls; prediabetics displayed a similar pattern. Asymptomatic/diabetes-prone rats also tended to have slightly higher blood cholesterol levels. The low incidence and delayed onset of the syndrome in rats fed a modified AIN-76 diet (27%, 127 +/- 21 days) compared to the previous chow-fed generation (60%, 93 +/- 18 days) and chow-fed littermates (38%, 87 +/- 16 days) suggested that diet can modify expression of the syndrome.

Animals↗
PubMed1982

Variation of rat serum biochemical values following decapitation or anesthesia with ether, halothane or Innovar-VetR: rapid Innovar-VetR-induced hyperuricemia and hyperglycemia.

True reference values (TRV) should ultimately be determined in blood from inactive, unstimulated rats but in practice, acceptable reference values (ARV) may be established using blood from decapitated or anesthetized animals if one is cognizant of variations associated with blood sampling procedures. Data reported here illustrate some variations in serum biochemical values following decapitation or anesthesia. Decapitation does not provide serum in which ARV for sodium, potassium or lactate dehydrogenase can be found but ARV can be determined for glucose, insulin and several other parameters. It is suggested that both TRV and ARV for serum electrolytes be determined using serum from cannulated rats. All three anesthetics raised glucose levels and ether and halothane increased alkaline phosphatase activity. Both halothane and Innovar-VetR decreased insulin:glucose ratios suggesting inhibition of insulin release from the pancreas. Innovar-VetR also produced hypoxia due to severe respiratory depression and bradycardia as well as hyperuricemia, hyperglycemia and hyperphosphatemia. Techniques most likely to provide ARV should be of the shortest possible duration, afford least respiratory and cardiovascular suppression and minimize stimulation of the sympathetic nervous system.

Anesthetics↗
PubMed1982

High pressure liquid chromatographic determination of mono- and disaccharides in presweetened cereals: Collaborative study.

A collaborative study was conducted using a modified AOAC method (sugars in chocolate) for the determination of fructose, glucose, sucrose, and maltose in presweetened cereals by high pressure liquid chromatography (HPLC). Eight samples consisting of 6 products were analyzed in duplicate by the HPLC method and the AOAC Lane-Eynon method. The AOAC method was modified to use water-alcohol (1 + 1) and Sep-Pak C18 cartridges for sample cleanup. The HPLC results indicate precision comparable to the lane-Eynon method and the chocolate method. The modified HPLC method has been adopted official first action.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Effect of dietary selenium and tumor status on the retention of 75Se by tissues and mammary tumors of DMBA-treated rats.

The effects of the presence of mammary tumors on 75Se retention was examined in DMBA-treated rats. Tumor bearing rats fed varying amounts of Se exhibited an inverse linear dose response between dietary Se intake and tissue retention of 75Se in whole body, heart, lungs, ovaries, adrenals, spleen, and muscle. Tumor 75Se retention, however, was independent of the dietary intake of Se. Tumor bearing rats excreted more 75 Se label in the urine compared to both control rats fed the same amount of Se and DMBA-treated animals that remained tumor free. In the short term, no significant differences were seen in tissue retention of 75Se. By 7 d, the increased urinary excretion of the label resulted in significantly decreased retention of 75Se in blood, spleen, liver, lungs, and kidneys of tumor-bearing rats compared to tumor-free animals. The presence of tumors, however, did not affect the liver distribution of the label among cytosolic proteins. These results suggest that tumor bearing animals have an accelerated urinary excretion of Se compared to animals without tumors and that tumors either have a very slow turnover of Se or a low priority for the element.

9,10-Dimethyl-1,2-benzanthracene↗