The effects of 2,3-diphosphoglycerate, adenosine triphosphate, and glycosylated hemoglobin on the hemoglobin-oxygen affinity of diabetic patients

The position of the oxygen dissociation curve (ODC) is modulated by 2,3-diphosphoglycerate (2,3-DPG). Decreases in 2,3-DPG concentration within the red cell shift the curve to the left, whereas increases in concentration cause a shift to the right of the ODC. Some earlier studies on diabetic patients have reported that insulin treatment may reduce the red cell concentrations of 2,3-DPG, causing a shift of the ODC to the left, but the reports are contradictory. Three groups were compared in the present study: 1) nondiabetic control individuals (N = 19); 2) insulin-dependent diabetes mellitus (IDDM) patients (on insulin treatment) (N = 19); 3) non-insulin-dependent diabetes mellitus (NIDDM) patients using oral hypoglycemic agents and no insulin treatment (N = 22). The overall position of the ODC was the same for the three groups despite an increase of the glycosylated hemoglobin fraction that was expected to shift the ODC to the left in both groups of diabetic patients (HbA1c: control, 4.6%; IDDM, 10.5%; NIDDM, 9.0%). In IDDM patients, the effect of the glycosylated hemoglobin fraction on the position of the ODC appeared to be counterbalanced by small though statistically significant increases in 2,3-DPG concentration from 2.05 (control) to 2.45 µmol/ml blood (IDDM). Though not statistically significant, an increase of 2,3-DPG also occurred in NIDDM patients, while red cell ATP levels were the same for all groups. The positions of the ODC were the same for control subjects, IDDM and NIDDM patients. Thus, the PO2 at 50% hemoglobin-oxygen saturation was 26.8, 28.2 and 28.5 mmHg for control, IDDM and NIDDM, respectively. In conclusion, our data question the idea of adverse side effects of insulin treatment on oxygen transport. In other words, the shift to the left reported by others to be caused by insulin treatment was not detected

Desempenho, características de carcaça e qualidade da carne de bovinos superprecoces das raças Canchim, Nelore e seus mestiços Performance, carcass traits and meat quality of young Canchim, Nellore and crossbread bulls

Oitenta e seis machos jovens, não-castrados, divididos em quatro grupos raciais - Nelore (n=20), Canchim (n=17), ½ Canchim &#215;Nelore (CN) (n=25) e �� Canchim &#215;Nelore (TQ) (n=24) - foram pesados a cada 28 dias para avaliação de ganho de peso (kg/dia), ingestão de matéria seca (kg/dia) e conversão alimentar. Ao atingirem peso de abate médio de 450 kg e espessura de gordura subcutânea superior a 4 mm, os animais foram abatidos para avaliação do peso e do rendimento de carcaça e de cortes comerciais do traseiro, área de olho-de-lombo, espessura de gordura subcutânea (mm), marmorização, força de cisalhamento, extrato etéreo (%) e perdas por cocção. O grupo Nelore apresentou-se adequado ao sistema de produção proposto, revelando desempenho similar ao dos animais CN quanto ao ganho de peso (1,18 e 1,29 kg para Nelore e CN, respectivamente) e conversão alimentar (6,90 e 7,04 para Nelore e CN, respectivamente). A ingestão de matéria seca (kg/dia) diferiu entre os grupos raciais (11,82; 9,39; 8,90 e 8,31 para Canchim, TQ, CN e Nelore, respectivamente). O peso da carcaça (kg) dos Canchim (291,14) foi maior e diferiu dos outros grupos (250,74; 246,64 e 244,18 para TQ, CN e Nelore, respectivamente). Apesar de o rendimento de carcaça ter sido maior no grupo Nelore (58,75%), os animais desse grupo apresentaram menor rendimento de cortes nobres que de traseiro, com diferença para o contrafilé (10,22; 11,55; 11,64 e 11,18 para Nelore, Canchim, TQ e CN, respectivamente). Os valores de força de cisalhamento comprovam que o abate de animais jovens garante carne macia, independentemente do grupo genético estudado.<br>Eighty six young bulls were used, divided into four genetic groups: Nellore (n=20), Canchim (n=17), ½ Canchim &#215;Nellore (NC) (n=25) and ¾ Canchim &#215;Nellore (TQ) (n=24). The animals were weighed every 28 days to evaluate the average daily gain (kg/day), dry matter intake (kg/day) and feed conversion. When the animals reached slaughter weight (450 kg) and fat thickness greater than 4 mm, were slaughtered to evaluate the rib eye area (cm²), subcutaneous fat thickness (mm), marbling, shear force, ether extract (%) and total cooking losses. The Nellore group fitted correctly into the proposed system, showing similar performance when compared to the CN group (1.18 and 1.29 kg/day for Nellore and CN, respectively) and feed conversion (6.90 and 7.04 for Nellore and CN, respectively). The dry matter intake (kg/day) differed among all groups (11.82, 9.39, 8.90 and 8.31 for Canchim, TQ, CN and Nellore, respectively). The carcass weight (kg) was higher in the Canchim group (291.14) than the other groups (250.74, 246.64 and 244.18 for TQ, CN and Nellore respectively). Although the carcass dressing percentage of the Nellore group (58.75%) was the highest, this group had the lowest yield of commercial cuts in the hindquarter especially for the sirloin (10.22, 11.55, 11.64 and 11.18% for Nellore, Canchim, TQ and CN, respectively). The shear force values indicated that the slaughter of young animals can assure tender beef regardless of the genetic group