Biomedical subjects

P H Holter

Publications and source records attributed to P H Holter.

10 recordsLinked to original sources

PubMed1990

Pulmonary function and energy expenditure after marked weight loss in obese women: observations before and one year after gastric banding.

Pulmonary function and pulmonary gas exchange at rest, and during and after a standard exercise load of 500 kpm in 1 min on bicycle ergometer were studied in 34 women with severe, uncomplicated obesity, aged 37.8 (20-59) years, before and 1 year after gastric banding, resulting in a weight loss from 113.2 (84-156) to 81.7 (60-110) kg. Following the weight loss, TLC and VC rose from 93 and 94 per cent of expected to 98 and 101 per cent, respectively. FRC, ERV and FRC/TLC rose more markedly from 77, 64 and 83 per cent to 98, 109 and 99 per cent. IC fell from 108 to 99 per cent. RV and RV/TLV remained unchanged. FEV1.0 rose from 97 to 103 per cent, while MVV rose from 102 to 112 per cent, i.e. above normal. TLCO and PaCO2 remained unchanged, at 90 and 95 per cent, whereas PaO2 rose from 86 to 91 per cent. Resting O2 intake (VO2) decreased from 147 to 115 per cent of the expected for normal weight women, while VO2/BSA decreased from 113 to 99 per cent, the changes being greater than expected from commonly used formulas for prediction of metabolic rate. O2 cost of work (EO2) decreased from 142 to 105 per cent. Resting ventilation (V) declined from 136 to 113 per cent, while ventilatory cost of work (EV) decreased from 142 to 105 per cent. CO2 recovery time after work (CO2RT) decreased from 121 to 100 per cent, while the ratios CO2RT to EO2 and to extra CO2 output of work (ECO2) rose slightly. Thus, the loss of weight led to increased filling of the lungs, improved dynamic function, reduced ventilation/perfusion disturbances and greater than expected reduction of energy expenditure, both at rest and exercise. In the obese state there was no evidence of alveolar hypoventilation or impaired ventilatory control. The beneficial effect of weight reduction on the exertional dyspnea included a combination of marked reduction of ventilatory demands and moderate rise in ventilatory capacity.

Adult↗

PubMed1988

Postnatal anemia and thrombocytosis in suckling rabbits: influence of delayed weaning and iron supplies.

Two groups of suckling rabbits were studied from the 15th to the 40th day after birth, one group receiving mothers milk only, the other having the choice of iron-containing food pellets from the 20th day. In the milk-only group, the plasma iron concentration (P-Fe), blood hemoglobin concentration (B-Hb), red blood cell count (B-RBC), and mean corpuscular volume (MCV) declined continuously, whereas the hemoglobin mass of the blood (Hb-mass) remained unchanged, and the blood platelet count (B-PLTS), plasma platelet count (P-PLTS), and the estimated platelet release to the blood (PLT-release) showed a continuous rise. The milk-pellet group showed the same pattern until the 25th-30th day; thereafter, P-Fe, B-Hb, and Hb-mass rose markedly, whereas B-PLTS and PLT-release declined. At the time of weaning, both groups showed bimodal erythrocyte volume distribution curves. Thereafter, the milk-only group developed a pure microcytemia, whereas the milk-pellet group got normovolemic erythrocytes only. In conclusion, the erythropoiesis in suckling rabbits is characterized by a balanced recycling of an essentially constant amount of available iron, preventing rise of Hb-mass. The anemia thus reflects a failure of the Hb-mass to keep up with the growth-related rise in plasma volume. A close relationship exists between postnatal iron deficient microcytic anemia and thrombocytosis.

Anemia, Neonatal↗

PubMed1987

Haemoglobin O2 binding in newborn and adult rabbits.

The relationship between haemoglobin O2 saturation and 2,3-diphosphoglycerate concentration (2,3-DPG) in haemoglobin solutions equilibrated with 3.7% O2-5.7% CO2 were identical in newborn and adult rabbits over a wide range of 2,3-DPG (0.5-40.0 mumol g-1 Hb), and independent of the haemoglobin concentration (1-10 g dl-1). Also, the resistance of the haemoglobin to alkali denaturation and the spectrophotometric absorption spectra of carboxy and oxyhaemoglobin between 500 nm and 650 nm, as well as the isoelectric focusing pattern of the haemoglobin after early and late stabilization with CO, were the same in newborn and adult animals. Both demonstrated one dominant band, focusing at pH 7.17, and one less conspicuous at pH 7.40. The erythrocyte pH was higher in the newborn than in the adult animals. Isoelectric focusing of erythrocyte pyruvate kinase demonstrated two isoenzyme bands in the newborn animals, one dominant fraction at pH 5.85 and one minor fraction at pH 7.97, whereas only the pH 7.97 band was observed in the adult. It is concluded that the physical properties of the haemoglobin molecule itself are the same in newborn and adult rabbits, and that the postnatal decrease in haemoglobin O2 affinity is solely due to changes in the erythrocyte metabolism, leading to a marked rise in 2,3-DPG and a minor decline in erythrocyte pH. The rise in 2,3-DPG is caused by decrease of pyruvate kinase, probably due to proteolytic inactivation of the enzyme.

2,3-Diphosphoglycerate↗

PubMed1986

Erythropoiesis-stimulating factor(s), erythropoiesis and erythrocyte 2,3-diphosphoglycerate in young rabbits with marked post-natal fall in haemoglobin.

The erythropoietic activity and erythrocyte 2,3-diphosphoglycerate (2,3-DPG) were studied during and after the nadir of the post-natal anaemia in normal, rapidly growing rabbits, from the 12th to the 35th day after birth. Whole blood haemoglobin (Hb) decreased from 9.3 g dl-1 on the 12th to 4.9 g dl-1 on the 25th day, while erythropoiesis-stimulating factor(s) (ESF) in plasma (determined by a cell culture assay) concomitantly rose from undetectable to high levels. In spite of marked rise in body weight, from 250 to 480 g, estimated haemoglobin mass (Hb mass) and reticulocyte mass production rate (Rt prod) remained essentially the same, about 1.8 g and 0.3 ml day-1. From the 25th to the 35th day, ESF decreased to a lower level, while Hb increased to 10.8 g dl-1 and Hb mass and Rt prod rose sharply, to 6.9 and 1.2 ml day-1. The 2,3-DPG rose markedly during the observation period, but showed a transient decline on the 29th day, simultaneously with the peak in reticulocyte counts (Rt) (24%) and release of young erythrocytes with low 2,3-DPG. The data indicate that the regions governing the erythropoietin production/release became increasingly sensitive to hypoxia during the observation period. The possibility also exists that the increase in ESF was due only in part to hypoxic stimulation. It could be related to the maturation of the animal in other ways, such as shift from extra-renal to renal erythropoietin production and the growth. The lack of response to increasing stimulation indicates that the erythropoiesis was restricted by the availability of iron and/or other factors necessary for erythrocyte and haemoglobin production.

2,3-Diphosphoglycerate↗

PubMed1985

Erythrocyte 2,3-diphosphoglycerate and erythropoietic activity in rabbits with severe bleeding anaemia superimposed in the early post-natal fall in haemoglobin.

Erythrocyte 2,3-diphosphoglycerate (2,3-DPG), whole blood haemoglobin (Hb), haematocrit (Hct), mean corpuscular haemoglobin concentration (MCHC) and reticulocyte percentage (Rt) were determined before and after bleeding in two groups of suckling chinchilla rabbits. One group was subjected to severe bleeding on the 12th, 15th, 18th and 21st day after birth and studied for 3 weeks, while the other was studied during the first 24 h after one severe bleeding on the 18th day. In the first group Hb and Hct fell to 2.7 g . dl-1 and 11.5%, respectively, on the 25th day. The fall was accompanied by a marked rise in Rt and decline in MCHC, reaching maximum and minimum on the 29th day, and a simultaneous, temporary decline in 2,3-DPG. In the other group the acute bleeding was accompanied by a marked fall in Hb and Hct, but no change in Rt and MCHC. 2,3-DPG was unchanged 8 h after the bleeding, but showed a rise during the following 16 h, definitely beyond the normal rise at this age. It is concluded that severe bleeding anaemia induces a rise in erythrocyte 2,3-DPG synthesis. However, the effect of the acute rise in 2,3-DPG is far from sufficient to maintain the O2 delivery capacity of the blood, and is completely offset by the influence of a subsequent change in the erythrocyte population towards younger cells with low 2,3-DPG.

2,3-Diphosphoglycerate↗

PubMed1985

Erythrocyte 2,3-diphosphoglycerate, PO2 50% and available O2 in rabbits with bleeding anaemia superimposed on the early post-natal fall in haemoglobin.

Erythrocyte 2,3-diphosphoglycerate (2,3-DPG), PO2 50%, whole blood haemoglobin (Hb), haematocrit (Hct) and available O2 were determined in two matched groups of suckling rabbits from the 17th to the 34th day after birth. One group was subjected to repeated bleeding, amounting to 1.0-1.5% of the body weight, on day 17, 19, 22 and 25, while the other served as control. The bleeding group had markedly lower Hb and Hct than the control group, which showed the ordinary post-natal fall in Hb. There were, however, no differences between 2,3-DPG and PO2 50% in the two groups. The changes were essentially the same as observed previously in animals in which the post-natal anaemia was avoided by iron-treatment. Thus, these and previously reported data show that the post-natal rise in 2,3-DPG and PO2 50% within wide limits is uninfluenced by marked variations in Hb, even severe bleeding anaemia, and support the assumption that the post-natal rise in 2,3-DPG and PO2 50% is dominated by processes related to the growth and maturation of the animals.

2,3-Diphosphoglycerate↗

PubMed1984

Erythrocyte 2,3-diphosphoglycerate, PO250%, and available oxygen in young rabbits with and without postnatal fall in hemoglobin.

We determined erythrocyte 2,3-diphosphoglycerate (2,3-DPG), PO250%, whole blood hemoglobin concentration, and available O2 from the 12th to the 30th d after birth in two matched groups of young rabbits. One group received iron parenterally on the 12th, 15th, and 18th d and the other received no iron supplement. In the untreated group there was a marked fall in hemoglobin concentration from the 12th to the 22nd d and thereafter a marked increase to the initial level on the 30th d whereas the iron-treated animals showed a marked rise in hemoglobin concentration from the 12th to the 22nd d, and a subsequent, slight decline from the 22nd to the 30th d. The average values of PO250% and 2,3-DPG, and the changes in PO250% and 2,3-DPG were virtually identical for both groups. During the first period (12-22 d) there was a marked rise in both 2,3-DPG and PO250% whereas in the second period (22-30 d) there was a somewhat smaller rise in 2,3-DPG and only a slight tendency toward a further rise in PO250%. In the untreated animals "available O2," reflecting the O2 delivery capacity of the blood, remained unchanged during the period of fall in hemoglobin concentration and showed a rise during the second period. In the iron-treated animals "available O2" rose markedly during the first period, with iron-treatment, and remained unchanged during the second period. We conclude that the marked postnatal rise in 2,3-DPG and PO250% in the rabbit seems to be independent of the changes in the hemoglobin concentration.

2,3-Diphosphoglycerate↗

PubMed1982

Erythrocyte 2,3-DPG, PO2 50% and available O2 during the early post-natal fall in hemoglobin in rabbits.

Erythrocyte 2,3-DPG, PO2 50%, whole blood hemoglobin and available O2, and fixed acid Bohr effect were studied during the first 10 days after birth in rapidly growing suckling rabbits. The post-natal fall in hemoglobin concentration was accompanied by a marked rise in erythrocyte 2,3-DPG and a gradual increase in PO2 50%. The rise in PO2 50% was sufficient to keep the available O2 of the blood unchanged throughout the observation period. The observations show that a 2,3-DPG mediated rise in PO2 50% very effectively contributes to maintenance of adequate tissue oxygenation during the post-natal fall in hemoglobin. The rise in 2,3-DPG and and PO2 50% may be due to the ordinary hypoxia-induced shift to the right of the hemoglobin O2 dissociation curve, as observed under other circumstances when blood hemoglobin is rapidly reduced, but the very marked rise in 2,3-DPG and the very low delta PO2 50%/delta 2,3-DPG ratio suggest that the rise may as well be due to hypoxia independent, pre-programmed processes. The fixed acid Bohr effect was essentially the same in newborn and adult rabbits, and was uninfluenced by large variations in 2,3-DPG.

2,3-Diphosphoglycerate↗

PubMed1981

Changes in 2,3-Diphosphoglycerate (2,3-DPG) after exercise.

Previous studies of the influence of physical exercise on erythrocyte 2,3-DPG have shown conflicting results, including that exercise induces increase, decrease or no changes in 2,3-DPG. Assuming that the interplay between the factors governing 2,3-DPG metabolism may change considerably during the early phase of recovery after exercise, the level of erythrocyte 2,3-DPG was examined over a prolonged period of time after heavy exercise in five healthy men, on 3 separate days, the duration of exercise being 6 min, 6 min + 6 min with 1 h of rest between, and 60 min, respectively. The short exercise periods were accompanied by a substantial lactate acidosis, whereas the 60 min work was essentially aerobic. With the 6 min work, the erythrocyte 2,3-DPG was unchanged or slightly reduced immediately after and 15 min after the end of exercise, then rose to a new level, 8% above the initial level, 30 min after the exercise (P less than 0.001). With the 6 + 6 min work, the pattern of change followed both bouts of exercise, resulting in a two-step increase of 2,3-DPG, to a new level 12% above its initial value (P less than 0.001). With the 60 min work, 2,3-DPG was increased after a new level, 10% above initial value, 45 min after the exercise (P less than 0.001). With all three types of exercise 2,3-DPG remained unchanged during the following 4 h. Thus, heavy exercise is followed by a definite, slowly developing increase in erythrocyte 2,3-DPG, reaching a new level 30-45 min after exercise.

2,3-Diphosphoglycerate↗

PubMedDate not supplied

Effect of iron treatment on erythrocyte parameters in postnatal anemia of the pig.

The development of postnatal anemia and the preventive and curative effect of iron supplementation were examined in 34 piglets from three litters of Norwegian Landrace pigs. A prostaglandin analog was given on day 111 or 112 of pregnancy, and the piglets were removed by caesarean section. Seventeen piglets were given 180 mg iron as colloidal ferridextran subcutaneously at birth (0 = day group); the remaining 17 were given the same amount on day 13 (13-day group). The piglets had access to a milk substitute from day 1 to day 7 and pelleted food for piglets after day 13. From about 4 weeks of age the piglets ate considerable amounts of pellets. The red blood cell count (RBC) and hemoglobin concentration (Hb) at birth were 3.2 +/- 0.4 (SD) x 10(12)/L and 80.4 +/- 8.1 x 10(12) g/L, respectively. In both groups Hb, RBC, mean corpuscular volume (MCV), and particularly packed cell volume (PCV) decreased markedly the first day after birth. In the 13-day group there was a further decrease until treatment with iron on day 13. Injection with iron on day 13 led to a rapid increase in the above mentioned parameters, with statistically significant increases for Hb, PCV, and MCV four days after treatment. The calculated mass of hemoglobin was fairly constant until treatment in the 13-day group. In the group given iron at birth the data obtained indicate that the amount of iron given is insufficient to sustain a production of normal-sized erythrocytes with a normal mean corpuscular hemoglobin concentration for more than approximately 21 days. Furthermore, the present study also indicates that MCV is a sensitive indicator of iron availability in piglets.

Anemia↗