Distribution of pulmonary blood flow has traditionally been regarded as determined by gravity. This view has been challenged recently by reports describing marked gravity-independent distribution of flow. These reports were based on experiments in which local blood flow was measured by methods that have not been thoroughly evaluated. In the present study, we showed that in the goat lung regional trapping of i.v. infused microspheres (O = 15 microns) correlated to endothelial uptake of a simultaneously i.v. infused diamine (r = 0.99, region size approximately 1.5 cm3, dry weight approximately 40 mg). This indicates that the deposition of microspheres reflects true regional pulmonary blood flow. Using the microsphere method, we found a marked gravity-independent heterogeneity in blood flow (coefficient of variation approximately 40%) in the awake goat. We could find no pattern related to anatomy that could account for this variability. We re-examined the influence of gravity by analysing the distribution of pulmonary blood flow in anaesthetized goats both in prone and supine positions. The dorsal to sternal distribution of flow appeared to be inverted when the animals were turned from prone to supine recumbency, indicating that gravity influenced the distribution of pulmonary blood flow along this axis. However, along the gravitational axis, distribution of blood flow varied considerably from lung to lung. It appears that in awake goats the distribution of pulmonary blood flow is the result of several different determinants.

Plasma acetoacetate concentration in the 1st mo of lactation and its relation to BW change, milk yield, DMI, and BW postpartum were studied in 361 first lactation cows during 6 yr. The cows were fed concentrate at 6 and 3 kg/d. Calvings took place from August to December. Single observations for all cows were fitted by a multitrait animal model that accounted for all genetic relationships. Heritability for acetoacetate was .11 with a genetic correlation of .87 for milk yield, -.65 for weight change, and -.13 for BW postpartum. Acetoacetate was higher at 3 kg/d of concentrate than at 6 kg/d, and calving after 3 to 4 mo of indoor feeding was related to higher acetoacetate than was calving shortly after the pasture season. Acetoacetate was related to weight loss postpartum, but at a different degree in different years. In some years, compounds of the silage caused strongly elevated plasma concentrations of acetoacetate after feeding. Experiments were performed to compare hay with silages of different qualities. Rumen concentration of different amines 3 h postfeeding was taken as an index of the amine load of the cow. The concentration of several amines in rumen fluid were high after feeding ketogenic silage.

We studied the kinetics of lysine, methionine, and threonine in six high-yielding dairy cows at peak lactation (stage 1) and 6 mo later (stage 2). The cows were fitted with cannulas in the rumen and duodenum and were automatically fed every 4th h. The three amino acids (AA) were administered intraruminally in mixtures at dosages of 100, 200, 300, and 400 mmol of each, together with polyethylene glycol (PEG) as a liquid marker. Mean rumen liquid pools at stages 1 and 2 were not significantly different. The mean liquid outflow decreased from 13.6 to 9.5 L/h, and there was a significant linear increase in the liquid outflow with increasing dosages of AA. No significant interaction was found between feeding levels and AA dosages on rates of apparent degradation and rumen escape values. Expressed as percentages of the dosage, all three AA studied showed a significant linear decrease in degradation and a significant increase in rumen escape values with increasing dosage. At the feeding levels in stages 1 and 2, the highest relative degradation rates (percentage of dosage) were observed for threonine. The relative degradation rate of methionine was significantly lower than of lysine at the high feeding level but significantly higher at the low feeding level. The mean rumen escape values of threonine, methionine, and lysine across dosages and feeding levels were 16.7, 22.1, and 20.5%, respectively. The flow of the administered AA into the duodenum during an 8-h period after administration increased with increasing dosages, with peak concentrations after 1 h. Thus, the amounts of rumen escape of the three AA were considerable at all dosages, even when the AA were administered in unprotected form.

Apparent rumen degradation and escape of 18 amino acids (AA) after individual administration intraruminally were studied using two nonpregnant, nonlactating, rumen-cannulated cows fed a ration containing hay and concentrate twice daily. The pulse-dosages of AA were 75, 150, 300, and 600 mmol. Polyethylene glycol was used as the liquid marker. Rates of apparent degradation during the first 60 min (initial degradation) varied markedly among the AA; rates were highest for Ser, Asn, Glu, and Gln and lowest for Tyr, Val, Arg, and His. At the 75-mmol dosage, which corresponded to an initial substrate concentration of about 1 mM of rumen fluid, initial degradation varied between 95 and 40% of the dosage, depending on the AA. Rates, expressed as percentages of the dosage, decreased as dosages increased. During the first 8 h after administration, escape of the AA increased from a mean of 9% at the lowest dosage to a mean of 21% at the highest dosage. At the highest dosage, Met caused a net increase in the concentration of 11 of the other AA in rumen fluid. Twelve of the AA administered caused a net increase in the concentration of Ala in rumen fluid. Methionine and Lys are among the AA considered to be limiting to milk yield. These AA showed relatively high rumen escape values and may be useful as feed supplements even in an unprotected form.

Nutritional status was studied over a period of 13 months in 34 patients with rheumatoid arthritis (RA). Seventeen patients fasted for 7-10 days, were then transferred to a gluten-free vegan diet for 3.5 months and finally to a lactovegetarian diet for 9 months. The remaining 17 patients followed a "normal" diet. After one month, the values for body mass index (BMI) and triceps skinfold thickness (TSF) were significantly reduced in the diet group compared with the values at inclusion (p < 0.001), whereas upper arm muscle area (UAMA) was not significantly reduced. Evaluation of the whole study course revealed a significantly lower BMI (p = 0.04) and TSF (p < 0.01) in the diet group compared with the control group. The concentration of insulin-like growth factor 1 (IGF1) was significantly reduced in the diet group after one month compared with the value at inclusion (p = 0.01), but the overall difference between the two groups was not significant. There were no overall significant differences with regard to VAMA, concentration of serum albumin, haemoglobin, ferritin, zinc and copper between the two groups. Thus fast, followed by diet manipulations for one year, had a minor impact on nutritional status in patients with RA.