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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Duodenal calcium absorption is depressed in alloxan and streptozotocin diabetic rats taking normal amounts to dietary vitamin D. Depression of absorption appears to be at least in part the result of altered metabolism of vitamin D with failure to form 1,25-dihydroxycholecalciferol (1,25-(OH)2D3), the vitamin D metabolite that acts directly on duodenum to stimulate calcium absorption. The South American plant Solanum malacoxylon causes extensive soft tissue calcification when ingested by cattle. An extract of this plant restores calcium absorption depressed by dietary strontium blockage of 1,25-(OH)2D3 formation in chicks. We gave an aqueous extract of S. malacoxylon to diabetic rats and restored duodenal calcium absorption to normal. These findings provide further evidence of the ability of a factor in the S. malacoxylon extract to mimic the actions of 1,25-(OH)2D3 on duodenal calcium transport and reinforce the hypothesis that abnormal vitamin D metabolism is an important determinant of depressed duodenal calcium absorption in diabetes.
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PMID:Depressed duodenal calcium absorption in the diabetic rat: restoration by Solanum malacoxylon. 12 46

Control and streptozotocin diabetic rats were studied at 5 and 12 days after induction of diabetes. Strontium absorption was measured by in situ perfusion of duodenum and ileum. Duodenal absorptive capacity (absorption per unit length) and absorptive specific activity (absorption per gram of dry weight mucosa) were depressed. Depression was present both at 5 days, when mucosal growth is similar in controls and diabetics, and at 12 days, when mucosal growth is 50% greater in diabetics. Effects of diabetes on ileal absorption were minimal in comparison with effects on duodenum. This depression of duodenal strontium absorption in the diabetic rat is analogous to effects of diabetes on calcium absorption and may be mediated by abnormal vitamin D metabolism.
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PMID:Effects of experimental diabetes on intestinal strontium absorption in the rat. 13 63

We tested the hypothesis that depressed duodenal calcium absorption in the streptozotocin diabetic rat is the consequence of diabetes rather than nephrotoxicity of the diabetogenic agent causing abnormal renal vitamin D metabolism. We treated streptozotocin diabetic rats with insulin and compared their duodenal calcium transport response with that of untreated diabetics and matched controls. Insulin treatment restored depressed calcium transport of diabetics to control levels in in vivo studies and significantly increased calcium transport in vitro. Previous studies showed that even in uncontrolled diabetes the mucosa retains the ability to respond to an end organ stimulus enhancing calcium transport: 1,25-dihydroxycholecalciferol corrects the defect, but vitamin D and 25-hydroxycholecalciferol are ineffective. Since 1,25-dihydroxycholecalciferol is synthesized in the kidney, these findings, in conjunction with the current study, are consistent with the association of experimental diabetes with a renal defect depressing synthesis of 1,25-dihydroxycholecalciferol. Since insulin treatment restores duodenal calcium transport, the renal defects is unlikely to be caused by streptozotocin nephrotoxicity.
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PMID:Insulin-treatment of diabetic rats: effects on duodenal calcium absorption. 13 10

A calcium binding protein has been purified 220 fold from rat kidney. The molecular weight of this protein (26 000-28 000) is more than double that of the duodenal calcium binding protein of the rat. In response to the stimuli of both streptozotocin diabetes and depletion and repletion with vitamin D, changes in the renal protein are minimal. This contrasts markedly with responses of the duodenal protein to the same stimuli: (a) there was marked depression of duodenal calcium binding protein by vitamin D depletion and diabetes; (b) duodenal calcium binding protein was restored by vitamin D treatment of depleted rats. The renal protein appears to be identical with a previously described 28 000 molecular weight protein from the kidney purified by a different technique (Hermsdorf, C.L. and Bronner, F. (1975) Biochim. Biophys. Acta 379, 553-561). In contrast to findings of the current study, previous investigators were unable to isolate the protein from vitamin D-deficient rats and postulated vitamin D dependence. The protein activator of cyclic AMP phosphodiesterase is a calcium binding protein found in many tissues including kidney. Based on lack of response to stimuli we used and similarity in method of isolation and properties, our renal calcium binding protein may be this protein activator.
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PMID:Renal calcium binding protein in the diabetic and vitamin D-depleted rat. 13 39

Duodenal calcium absorption and a vitamin D-dependent duodenal calcium-binding protein are depressed in rats with alloxan- or streptozotocin-induced diabetes. To test for possible abnormal vitamin D metabolism in diabetes we measured serum concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D in control, streptozotocin diabetic, and insulin-treated diabetic rats. The serum concentration of 1,25-dihydroxyvitamin D was depressed in untreated diabetic rats to one-eighth of the level in controls and was restored to control levels by insulin treatment. The serum concentration of 25-hydroxyvitamin D was the same in all three groups. Hence, effects of diabetes on duodenal calcium transport can be explained by reduced concentrations of 1,25-dihydroxyvitamin D resulting either from failure of renal 1alpha-hydroxylation of 25-hydroxyvitamin D or increased catabolism of 1,25-dihydroxyvitamin D.
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PMID:Experimental diabetes reduces circulating 1,25-dihydroxyvitamin D in the rat. 14 Oct 98

We studied diabetic rats, 5 days after streptozotocin injection, and matched controls to determine whether depressed duodenal calcium absorption associated with uncontrolled diabetes in the rat would respond to vitamin D or its metabolites. At the appropriate time following the intravenous injection of 0.25 mug of either vitamin D3, 25-hydroxycholecalciferol (25-OHD3), 1,25-dihydroxycholecalciferol (1,25-OH)2D3), or 1alpha-hydroxycholecalciferol (1alpha-OHD3) to half of each diabetic and control group, calcium transport was evaluated using everted duodenal sacs with 0.4 mM40Ca and tracer 45Ca on both mucosal and serosal surfaces. All agents stimulated duodenal calcium absorption in controls. Diabetics responded only to 1,25-(OH)2D3, the metabolite that acts directly on the duodenum, and to its synthetic analog, 1alpha-OHD3. 1alpha-OHD3 is activated to 1,25-(OH)2D3 by 25-hydroxylation in the liver; 25-OHD3 must be 1alpha-hydroxylated in the kidney to be active. The stimulation of duodenal calcium absorption in diabetic rats by 1alpha-OHD3, but not by either vitamin D3 or 25-OHD3, is most consistent with a defect in vitamin D metabolism at the 1alpha-hydroxylation step in the kidney.
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PMID:Effects of vitamin D and its metabolites on calcium transport in the diabetic rat. 18 68

The authors discuss the main features of the complex pathophysiology of patients subjected to duodenocephalopancreatectomy, and particularly the difficulties inherent in clinical assessment of the digestive and metabolic impairment consequent upon the duodeno-gastro-pancreatic mutilation. Out of a total of 57 cases of this description, they singled out for recheck 23 patients who had undergone duodenocephalopancreatectomy not less than six months and not more than seven years before (chronic pancreatitis, 11 cases; various malignancies of the periampullar area, 10 cases; Zollinger-Ellison syndrome, 1 case; retroperitoneal lymphoma, 1 case). Seventy-six per cent of patients who had been gainfully employed were able to resume their jobs after surgery. Steatorrhea, assessed in terms of fecal fats, was present in all cases; notwithstanding, 70% of the patients gained weight (average increase 7 kg). All patients were on enzyme replacement therapy. Only 4% developed diabetes, and none developed postoperative peptic ulcers. Conversely there was a high incidence (65%) of bone structure reshuffling, signally osteoporosis, probably imputable to steatorrhea and vitamin D malabsorption, plus the often associated increase of serum alkaline phosphatase activity.
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PMID:[The biological results of duodenocephalopancreatectomy. Clinical evaluations based on a long-term follow-up]. 53 2

Nutrient requirements do not change markedly with advancing age, but life style, socioeconomic status, psychologic changes, and the presence of chronic disease alter nutrient intake in the elderly. It is important to recognize and deal with these factors in attempting to correct malnutrition and in prescribing dietary treatment. Malnutrition includes a variety of disorders: undernutrition, nutrient deficiencies and imbalances, and obesity. Frequent small feedings, with nutritional supplements for patients with profound weight loss, are the initial treatment for undernutrition. Iron supplements and a diet of foods rich in iron and in promoting iron absorption are required in treating iron deficiency anemia. Management of macrocytic anemia should include specific nutrient therapy plus improvement of diet to include leafy vegetables and animal foodstuffs. Diet is an important adjunct in treating chronic diseases. Maturity-onset diabetes mellitus often can be managed by diet alone, with attention to correct proportions of fat, carbohydrate, and protein and to the decreased caloric requirements of elderly patients. The importance of continuing dietary modifications in hyperlipidemia and hypertension is well known. Although dietary manipulation in osteoporosis is not curative, a diet high in calcium and containing adequate floride and vitamin D affords maximum dietary protection against progress of the disease.
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PMID:Guidelines for maintaining adequate nutrition in old age. 64 78

A progressive rise in arterial calcium content is the most characteristic age-associated alteration in the arterial wall and the decisive factor in arteriosclerotic degeneration. Experimental studies have demonstrated that calcium antagonists can prevent or retard the development of arterial calcinosis associated with vitamin D overload, hypertension or alloxan-induced diabetes. Although similar effects are more difficult to observe in humans, they have been demonstrated in patients with coronary artery disease and in patients with end-stage renal disease, which is characterised by an acceleration of the normal arterial aging process.
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PMID:Arterial calcinosis, chronic renal failure and calcium antagonism. 128 73

Histomorphometric examination and histological observation of femoral bone were performed on long-standing neonatal streptozotocin-induced diabetic rats (n2STZ, n5STZ) as a human model of non-insulin-dependent diabetes mellitus. The growth and strength of femurs decreased in the STZ diabetic rats. Histomorphometric parameters such as cortical bone thickness, number of metaphysical trabeculae and percent trabecular volume of metaphysical area all significantly decreased in the STZ diabetic rats. There were no significant differences in parameters between the n2STZ and n5STZ diabetic rats. Histological findings demonstrated no significant change in the number of osteoclasts in femur nor change corresponding to osteomalacia. Bone absorption in the STZ diabetic rats appeared unchanged. The plasma calcium level did not change in the STZ diabetic rats, although their plasma phosphate or A1-p levels increased. Circulating 24, 25 (OH)2D3 was significantly lower in the STZ diabetic rats than the controls. However, 25 (OH) D3 or biologically active 1, 25 (OH)2D3 was not different between the controls and STZ diabetic rats. Osteopenia is thus present in the femurs of long-standing neonatal STZ diabetic rats, due in part to abnormal vitamin D metabolism.
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PMID:Alterations in femoral bone histomorphometry and vitamin D metabolism in neonatal streptozotocin-induced diabetic rat. 133 71


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