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PubMed1989

[Therapeutic effect of stage III breast cancer--comparative study of preoperative intra-arterial infusion chemotherapy and non-infusion therapy].

Between January 1977 and March 1988, 111 patients of stage III breast cancer were treated in Sapporo Medical College. The median age was 51.6 years (range, 26-83 years). Menopausal status was 47 cases of premenopausal, 19 cases of perimenopausal and 45 cases of postomenopausal. Fifty-seven of these patients received intra-arterial infusion chemotherapy. The anticancer drugs were mainly given by two routes, infusion into the internal mammary artery and the subclavian artery. Continuous infusion of 5-FU and intermittent injections of MMC, ADR or 4'-epi-ADR were jointly or individually made in each artery. Clinico-histological response was studied in 53 out of 57 patients. Clinical response, defined as CR + PR, was noted in 33 patients (62.3%). Histological response according to Shimosato Criteria, defined as grade IIb or better, appeared in 31 patients (58.5%). Non-infusion group contained 27.7% of stage IIIb, against 72.2% in infusion group. The 5-year overall survival rates were; non-infusion group 62%, 5-FU infusion group 34.1%, and ADR MMC group 66.2%. A significant difference was seen between 5-FU infusion group and ADR-MMC group (p = 0.03). The median disease-free interval was 22.0 months (range, 1-77 months) in infusion group and 28.2 months (range, 1-124 months) in non-infusion group. MMC + ADR combination group revealed the most excellent results in terms of the 5 year survival rate and clinicohistological effect.

Adult↗
PubMedDate not supplied

Comparable safety and antiemetic efficacy of a brief (30-second bolus) intravenous granisetron infusion and a standard (15-minute) intravenous ondansetron infusion in breast cancer patients receiving moderately emetogenic chemotherapy.

PURPOSE: For patients receiving chemotherapy, optimization of antiemetic therapy in terms of safety of administration, efficacy, cost, and convenience remains a subject of intense clinical research. In this study, we evaluated and compared the safety and antiemetic efficacy of a single 30-second intravenous bolus infusion of granisetron which those of a standard 15-minute intravenous infusion of ondansetron in chemotherapy-naive breast cancer patients receiving moderately emetogenic chemotherapy. PATIENTS AND MATERIALS: This was a randomized, double-blind, double-dummy, multicenter crossover study of 623 chemotherapy-naive patients (two male, 621 female) receiving moderately emetogenic chemotherapy (cyclophosphamide plus doxorubicin, with or without 5-fluorouracil) for breast cancer. Patients were assigned randomly to receive either granisetron or ondansetron in cycle 1 and the other agent in cycle 2. Granisetron (10 micrograms/kg) was administered as a 30-second intravenous bolus infusion within 5 minutes before the start of chemotherapy, and ondansetron (32 mg) was administered as a 15-minute intravenous infusion beginning 30 minutes before the start of chemotherapy. A total of 573 patients received the two planned chemotherapy cycles. Safety assessment was based on the type and frequency of adverse experiences reported by the patient at 24 and 48 hours after chemotherapy began. Efficacy assessments included the occurrence of nausea or emesis and the proportion of patients who achieved total emetic control at 24 and 48 hours after chemotherapy. RESULTS: Similar proportions of patients in both treatment groups remained free of emesis at the 24-hour assessment period (58.6% and 62.7% of granisetron- and ondansetron-treated patients, respectively) and at 48 hours (42.2% and 45.0% for granisetron vs ondansetron) in both cycles. The proportions of granisetron- and ondansetron-treated patients who remained nausea-free for the first 24 hours after treatment in both cycles were 44.0% and 48.5%, respectively, and at 48 hours were 26.7% and 31.0%, respectively. Statistical analysis demonstrated no significant treatment-by-cycle interaction. The 30-second granisetron infusion and the 15-minute ondansetron infusion were well tolerated. However, administration of ondansetron as a 15-minute intravenous infusion produced abnormal vision (6.28%) in significantly more patients than granisetron (0.35%). DISCUSSION: These two intravenous 5-hydroxytryptamine3-receptor antagonist antiemetics were similarly effective in controlling acute nausea and emesis during two cycles of moderately emetogenic chemotherapy. Granisetron (30 seconds) and the longer infusion of ondansetron (15 minutes) were well tolerated; however, ondansetron was associated with a greater proportion of patients reporting abnormal vision. Granisetron administered as a 30-second bolus infusion allows a considerably shorter waiting time between the end of the antiemetic infusion and the initiation of chemotherapy. This shorter administration time may enhance patient convenience and provider efficiency.

Adult↗
PubMed1990

Effects of isoenergetic infusions of propionate and glucose on portal-drained visceral nutrient flux and concentrations of hormones in lambs maintained by total intragastric infusion.

Three lambs were used in a repeated Latin square design to determine the influence of isoenergetic infusions of propionate or glucose on portal-drained visceral flux (PDV) of nutrients and concentrations of insulin, glucagon, growth hormone and prolactin. Lambs were fitted with appropriate catheters for blood sampling and maintained on total intragastric infusion of nutrients. Basal VFA, casein, mineral and vitamin infusions (isocaloric and isonitrogenous) were supplemented with an additional 22 +/- .5 kcal/h from propionate, glucose or a combination of propionate plus glucose. Ruminal fluid proportion and arterial blood concentration and PDV flux of propionate increased (P less than .10) by 17 mol/100 mol, .02 mM and 40 mmol/h, respectively, with infusion of an additional 61 mmol/h of propionate. Regression equations predicted that, on a net basis, 67% of ruminally infused propionate and 43% of abomasally infused glucose appeared in portal blood. Arterial L-lactate, beta-hydroxybutyrate and acetate concentrations, and beta-hydroxybutyrate flux were increased (P less than .10) by .34 mM, .20 mM, .50 mM and 4.2 mmol/h, respectively, with infusion of 33 mmol/h of added glucose. Net utilization of glucose by the PDV was approximately 4.4 mmol/h when no glucose was infused. Increased infusion of propionate resulted in a 22.2-micrograms/h increase in PDV flux of insulin (P less than .08) but had no effect on arterial insulin, glucagon and prolactin concentrations (P greater than .10). Arterial growth hormone increased by 3.8 ng/ml with increasing glucose infusion (P less than .08).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Absence of particle-induced coronary vasoconstriction during cardioplegic infusion: is it desirable to use a microfilter in the infusion line?

Many cardiac surgical units now use a microfilter in the infusion line for delivery of crystalloid cardioplegic solution to protect against the potential hazards of particulate contamination of cardioplegic solution. The aim of this group of studies was to determine the effects of particulate contamination of cardioplegic solutions, in order to establish whether a microfilter is needed in the infusion line. Total particle counts performed on two commercial cardioplegic solutions were low, but there were sufficient particles greater than 10 microns in diameter to cause coronary vasoconstriction. In isolated rat hearts a 20-minute infusion of St. Thomas' Hospital cardioplegic solution produced a progressive reduction in coronary flow, which was not prevented by the inclusion of a 0.8 micron filter in the infusion line. Two studies were performed on canine hearts to determine the effects of unfiltered cardioplegic solution on coronary vascular resistance. In the first, cardioplegic solution at 20 degrees C was infused for 20 minutes at a constant pressure of 50 mm Hg and flow rate was measured. In the second, the same solution at 4 degrees C was infused at a constant flow rate for 2 1/2 minutes and the infusion pressure was measured. In neither study did coronary vascular resistance rise. A final clinical study involving patients undergoing coronary bypass surgery compared the effects on coronary resistance of infusion at a constant flow of filtered versus unfiltered cardioplegic solution (n = 10 in each group). There was a similar rise in coronary perfusion pressure in both groups during the infusion. We conclude that there is insufficient evidence of particle-induced coronary vasoconstriction to justify the expense of a microfilter in the cardioplegic infusion line.

Animals↗
PubMedDate not supplied

The value of the dehydroepiandrosterone-annexed vitamin C infusion treatment in the clinical control of chronic fatigue syndrome (CFS). I. A Pilot study of the new vitamin C infusion treatment with a volunteer CFS patient.

A series of publications from our laboratory have indicated that the practice of megadose vitamin C drip infusion treatment enhanced the activity of endogenous glucocorticoids in such a way as to improve the clinical course of allergy and autoimmune disease-a disease entity that is known to respond to the therapeutic effect of glucocorticoids. The present paper represents an extention of our vitamin C studies, and intends to investigate the problem whether or not chronic fatigue syndrome (CFS), an acquired immunodeficiency disease, can also be counted as one of the candidate diseases for the vitamin C infusion treatment. We prepared two kinds of vitamin C infusion sets for the clinical use: the dehydroepiandrosterone-annexed vitamin C infusion set (the new set) and the annex-free vitamin C infusion set (the old set). The new set was expected to enhance the endogenous activities of both glucocorticoids and gonadal steroids. We followed the clinical course of a male CFS patient using the old and new vitamin C infusion sets, and with and without the oral intake of erythromycin and chloramphenico. Results obtained are as follows: a) the observation period of a study subject covered a period of August 1995 to May 1996. Combination of pneumonia signs and dermatomyositis signs marked the onset of his CFS. b) Old infusion treatment together with the short term antibiotics treatment was found effective for the control of pneumonia in the first stage of the disease (from August to October, 1995). c) Signs of pneumonia recurrence gradually became eminent in the second stage of disease (from November, 1995, to January, 1996) in spite of the moderate frequency of the old treatment together with stepwise prolongation of the antibiotics treatment. d) The alternate practice of the old and new infusion treatments together with the long-term antibiotics treatment, as conducted in the 3rd stage of disease (from February to May, 1996) led to substantial extinction of pneumonia signs (leucocytosis, tachycardia etc). e) The practice of the new infusion treatment markedly increased the excretion of both 17-ketosteroids and 17-hydroxycorticosteroids in the urine. Evidence was also available to indicate that the dehydroepiandrosterone annex was converted to testosterone, which in turn made a contribution to the control of CFS. f) The immunological survey of lymphocyte subsets including NK cell percent failed to find a coherent change in a study subject with CFS. In conclusion, the above results could be taken as evidence to indicate that the new vitamin C infusion treatment effectuates the clinical control of CFS by fortifying the endogenous activities of both cortisol and testosterone. The significance of parallelism between pulmonary infection and CFS, as observed in the clinical course of the test subject, was discussed in the light of the focal infection theory of nephritis.

17-Hydroxycorticosteroids↗
PubMed2006

No change in apolipoprotein AI metabolism when subcutaneous insulin infusion is replaced by intraperitoneal insulin infusion in type 1 diabetic patients.

In type 1 diabetic patients, the replacement of subcutaneous insulin infusion by intraperitoneal insulin infusion restores the normal physiological gradient between the portal vein and the peripheral circulation, which is likely to modify HDL metabolism. This stable isotope kinetic study was designed to compare HDL apolipoprotein (apo) AI metabolism in seven type 1 diabetic patients first treated by continuous subcutaneous insulin infusion by an external pump and then 3 months after the beginning of intraperitoneal insulin infusion by an implantable pump. Glycaemic control was comparable under subcutaneous and intraperitoneal insulin infusion (HbA1c=7.34+/-0.94% versus 7.24+/-1.00%, NS). HDL composition was similar under both insulin regimens (esterified cholesterol=20.1+/-2.5% versus 24.0+/-3.0% (NS), free cholesterol=3.4+/-1.1% versus 3.3+/-0.9% (NS), triglycerides=2.4+/-0.9% versus 2.1+/-0.9% (NS), phospholipids=22.7+/-5.3% versus 25.2+/-6.5% (NS) and proteins=51.2+/-6.3% versus 45.5+/-4.7% (NS)). The replacement of subcutaneous insulin infusion by intraperitoneal insulin infusion induced significant changes neither in apoAI fractional catabolic rate, nor in apoAI production rate, nor in apoAI pool size (respectively, 0.199+/-0.051 pool d(-1) versus 0.211+/-0.017 pool d(-1), 12.0+/-3.2 mg kg(-1)d(-1) versus 12.1+/-1.8 mg kg(-1)d(-1), 60.4+/-5.0 mg kg(-1) versus 57.5+/-7.5 mg kg(-1)). In conclusion, HDL metabolism is not modified by the replacement of subcutaneous insulin infusion by intraperitoneal insulin infusion when glycaemia is well controlled under both insulin regimens. As far as HDL metabolism is concerned there is no advantage in favour of one way of insulin administration or another.

Administration, Cutaneous↗
PubMed1977

Pharmacologic studies of continuous infusion of arabinosylcytosine by liquid infusion system.

Arabinosylcytosine (ara-C) was administered by prolonged intravenous infusion with a portable liquid infusion system (LIS) to patients with acute myelogenous leukemia. With the use of tritiated ara-C and this portable system, pharmacologic studies were performed in 8 patients. Most of the plasma radioactivity is in the deaminated product, arabinosyluracil (ara-U). After continuous intravenous infusion, a constant ara-C level is achieved slowly in the plasma. Unless a loading (priming) dose is administered immediately before beginning the infusion, a steady-state ara-C level cannot be achieved until 8 to 24 hr after the infusion. The infusion system has two mechanisms--one for giving a loading dose (3 ml/min) and the other for regular infusion at a rate of 0.5 to 2.0 ml/hr. If a loading dose is given before continuous infusion, a steady-state are-C level is achieved within an hour. The plasma ara-C disappearance curves are biphasic with a terminal half-life of 104 min, which is the same as that of a single injection. The cumulative urinary excretion after approximately 23 hr of infusion varied from 14% to 35% in different patients; more than 90% is ara-U and the remainder is ara-C. Our results have demonstrated that LIS can be used conveniently to sustain a constant plasma level of ara-C. The LIS increases mobility of both inpatients and outpatients and is particularly convenient for ambulatory patients.

Arabinofuranosyluracil↗
PubMed2003

The Power Infuser: a new device for rapid fluid infusion.

This study examined the effectiveness and ease of use of the ID Power Infuser, a pocket-sized device that can infuse fluid at rates up to 6 L/hr. Forty-six adults presenting with non-traumatic hypotension or clinical hypovolemia had 0.9% NaCl solution infused by the ID Power Infuser through a peripheral i.v. catheter. Eighteen patients with hemodynamic evidence of hypovolemia had a mean infusion rate of 2 L/hr with time to resolution of hypovolemia 28.5 +/- 7 min, 14 of these had an infusion rate > or = 4 L/hr with resolution of hypovolemia of 13.7 +/- 5.8 min. Resolution of hypovolemia was significantly faster compared with a group receiving gravity infusion. Use of the Power Infuser was deemed easy (VAS = 1.9 +/- 1.9 cm). The ID Power Infuser can accurately and quickly deliver i.v. crystalloid in the ED and has the potential to reduce morbidity, time in the ED, and costs.

Adult↗
PubMed1981

Determination of 24-hour insulin infusion pattern by an artificial endocrine pancreas for intravenous insulin infusion with a miniature pump.

UNLABELLED: Intravenous insulin infusion with a glucose controlled insulin infusion system (GCIIS) is known to restore glucose homeostasis. A simpler approach to improve blood glucose regulation is preprogrammed intravenous insulin infusion with portable pumps without sensor-mediated feedback. We report a study designed to evaluate whether the preprogrammed insulin infusion pattern to be used in the miniature insulin infusion pump (MIIP) could be optimized by concomitant employment of the GCIIS for blood glucose control. Six juvenile-onset insulin-dependent diabetics (mean age 31 yrs) were studied. Mean blood glucose (MBG) was 6.2 mmol/l +/- 0.5 (SD) during glucose controlled infusion and 5.3 +/- 0.6 during the combined MIIP + GCIIS-day. The insulin requirements calculated from the s.c. regimen (56 U +/- 10 SD) were identical to the GCIIS-measured (51 U +/- 14) and to the amounts delivered during the combined MIIP-GCIIS infusion day (54 U +/- 13). A mean surplus of 3 U was given by the GCIIS. Mean amplitude of glycaemic excursions (MAGE) was 3.0 mmol/l during GCIIS-control, and 3.3 mmol/l during combined infusion. IN CONCLUSION: The GCIIS was found capable of calculating the 24-hour insulin dose in well-known, unstable diabetics; however, it did not improve the preprogrammed insulin infusion profile obtained by the MIIP.

Artificial Organs↗
PubMed1994

Continuous infusion versus intermittent short infusion of metoclopramide for cisplatin-induced acute emesis.

Metoclopramide is an active antiemetic against cisplatin-induced acute emesis. However, the optimal administration method (continuous infusion versus intermittent short infusion) for metoclopramide has not yet been clearly defined. We have conducted a randomized crossover study to compare the antiemetic efficacy of continuous infusion of metoclopramide with that of intermittent short infusion of metoclopramide in 54 evaluable patients. Patients were stratified according to sex and were randomized to receive either a continuous-infusion regimen (regimen A) or an intermittent-short infusion regimen (regimen B). Patients were switched to the alternate therapy in the second course. In regimen A, metoclopramide at 3 mg/kg i.v. was given before cisplatin, and then metoclopramide at 4 mg/kg was infused intravenously over 7.5 hours. In regimen B, metoclopramide at 3 mg/kg i.v. was followed by 2 mg/kg i.v. for two doses. Dexamethasone and diphenhydramine were given intravenously in both regimens. There was no significant difference between two regimens in their ability to prevent emesis. Complete protection (no episode of emesis) and major protection (< or = 2 episodes of emesis), respectively, were obtained by 67% (95% confidence interval: 53-79%) and 85% (95% confidence interval: 73-93%) of all patients given regimen A and by 59% (95% confidence interval: 45-72%) and 81% (95% confidence interval: 68-91%) of those given regimen B. The two regimens were also equally effective in controlling nausea. However, male patients showed better control of nausea and vomiting than did female patients, regardless of treatment regimen. Toxicity was mild in both regimens and was well tolerated. Our findings indicate that both continuous-infusion metoclopramide and intermittent-short infusion metoclopramide are effective in controlling cisplatin-induced acute nausea and vomiting.

Acute Disease↗
PubMed2005

Volume turnover kinetics of fluid shifts after hemorrhage, fluid infusion, and the combination of hemorrhage and fluid infusion in sheep.

BACKGROUND: Hemorrhage is commonly treated with intravenous infusion of crystalloids. However, the dynamics of fluid shifts between body fluid spaces are not completely known, causing contradictory recommendations regarding timing and volume of fluid infusions. The authors have developed a turnover model that characterizes these fluid shifts. METHODS: Conscious, chronically instrumented sheep (n = 12) were randomly assigned to three protocol groups: infusion of 25 ml/kg of 0.9% saline over 20 min (infusion only), hemorrhage of 300 ml (7.8 +/- 1.1 ml/kg) over 5 min (hemorrhage only), and hemorrhage of 300 ml over 5 min followed by infusion as noted above (hemorrhage plus infusion). A two-compartment volume turnover kinetic model containing seven model parameters was fitted to data obtained by repeated sampling of hemoglobin concentration and urinary excretion. RESULTS: The volume turnover model successfully predicted fluid shifts. Mean baseline volumes of the central and tissue compartments were 1799 +/- 1276 ml and 7653 +/- 5478 ml, respectively. Immediate fluid infusion failed to prevent hemorrhage-induced depression of cardiac output and diuresis. The model suggested that volume recruitment to the central compartment after hemorrhage was primarily achieved by mechanisms other than volume equilibration between the two model compartments. CONCLUSION: Volume turnover kinetics is a promising tool for explaining fluid shifts between body compartments after perturbations such as hemorrhage and intravenous fluid infusions. The pronounced inhibition of renal output after hemorrhage prevailed regardless of fluid infusion and caused fluid retention, which expanded the tissue compartment.

Algorithms↗
PubMed1986

Modulation of LH-secretion in ovariectomized ewes by constant infusions of oestradiol and 4-hydroxyoestradiol: effects of varying infusion times and of high oestrogen doses.

Ovariectomized ewes were infused for different times (2-24 h) during the breeding season (September to February) with oestradiol (E2, 2 micrograms/h) or the catecholoestrogen 4-hydroxyoestradiol (4-OHE2, 10 micrograms/h). At these infusion rates comparable plasma levels of E2 and 4-OHE2 were obtained when steady state was reached after 3 h (E2: 20 +/- 4 pg/ml; 4-OHE2: 22 +/- 3 pg/ml). When E2 was infused for at least 6 h, all animals had significant LH-surges, starting 14-16 h after the beginning of oestrogen treatment, even when E2 was infused for up to 24 h. 4-OHE2, however, had only to be infused for 4 h to induce significant LH-surges in all animals tested. When E2 was infused for 12 h at a rate of 100 micrograms/h, the LH-surges in these ewes were significantly lower than the LH-surges in the same animals treated for 12 h with E2 at a rate of 2 micrograms/h. These data indicate: Once E2 has been administered at a specific infusion rate for a critical time period of 6 h, LH-surges occur, no matter whether the E2-infusion is continued or stopped. For the catecholoestrogen 4-OHE2 this critical time period amounts only to 4 h, if comparable plasma levels of either oestrogen are achieved. This might hint at a prolonged intracellular action of 4-OHE2 as compared to E2. At extremely high infusion rates of E2 (100 micrograms/h for 12 h) the positive oestrogen effect is significantly impaired, a finding supporting the concept of a bell-shaped dose-response relationship between oestrogens and their positive effect on LH-secretion.

Animals↗
PubMed1995

Paclitaxel by 3-hour infusion followed by 96-hour infusion on failure in patients with refractory malignant disease.

To explore the potential therapeutic differences between 3- and 96-hour infusions of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in patients with refractory malignant diseases, we conducted a phase II study in which patients were treated first with paclitaxel 135 mg/m2 by 3-hour infusion. If patients did not respond or relapsed after response, they were then treated by 96-hour infusion of paclitaxel at the same dose. Patients with metastatic or incurable breast, ovarian, lung, head/neck carcinomas, and lymphoma were eligible. They were required to have an Eastern Cooperative Oncology Group performance status of 2 or better and adequate hematologic, hepatic, and renal functions. In 22 patients entered thus far, we have observed one partial response in 10 lung cancer patients treated by 3-hour paclitaxel and one partial response in six patients treated by 96-hour infusion. Four partial responses were observed with 3-hour paclitaxel alone in nine breast cancer patients, while three partial responses occurred in five patients with 96-hour infusion after the 3-hour infusion failed. Nonhematologic toxicities such as fatigue, peripheral neuropathy, and mucositis occurred more commonly in the 96-hour infusion group. Our preliminary results suggest (1) that 3-hour infusion of paclitaxel is active against refractory breast cancer, (2) that 96-hour infusion of paclitaxel can induce partial response in breast cancer that was refractory to 3-hour treatment of paclitaxel, and (3) that more studies are needed to define the optimal treatment schedule of paclitaxel.

Adult↗
PubMed1997

Effect of a 15-minute infusion of DDAVP on the pharmacokinetics and pharmacodynamics of REVASC during a four-hour intravenous infusion in healthy male volunteers.

Plasma pharmacokinetics, effect on coagulation parameters, and safety and tolerability of an intravenous infusion of REVASC before, during and after a DDAVP infusion were investigated. Twelve healthy volunteers were given an intravenous bolus dose followed by a constant rate four-hour infusion of REVASC. Fifteen-minute infusions of 0.9% saline and DDAVP were started two and three hours respectively after the start of the REVASC infusion. Plasma REVASC concentrations were not affected by either the saline or DDAVP infusion. REVASC infusion produced an increase in APTT which plateaued between 0.5 and 3 hours. After the DDAVP infusion there was a tendency towards a new lower plateau whilst the REVASC infusion continued. There were no serious adverse events or bleeding episodes throughout the study. In conclusion, the co-administration of intravenous DDAVP has no effect on the plasma pharmacokinetics of REVASC and partially reverses the REVASC-induced increase in APTT. This may represent a role for DDAVP in the partial reversal of anticoagulation induced by REVASC.

Adult↗
PubMed1995

Effects of intraruminal infusion of propionate on the concentrations of ammonia and insulin in peripheral blood of cows receiving an intraruminal infusion of urea.

To test the hypothesis that propionate can reduce hepatic capacity to detoxify ammonia, effects of the inclusion of propionate in intraruminal infusions of urea on the concentrations of ammonia, other metabolites and insulin in peripheral blood were investigated in two experiments with non-lactating dairy cows. Both experiments were of a 4 x 4 Latin square design with four animals, four treatments and four experimental periods of 7 d; feed was given in two equal meals each day, all intraruminal infusions were given for 1 h at the time of the morning feed, and propionic acid was partly neutralized with NaOH. In Expt 1, the treatments were a basal diet of pelleted lucerne and chopped hay alone or with the following infusions (g/d): urea 80, propionic acid 350, urea 80 plus propionic acid 350. The inclusion of propionate in the urea infusion markedly increased (P < 0.001) the concentration of ammonia in plasma compared with infusion of urea alone. Moreover, the inclusion of urea with the propionate infusion abolished (P < 0.01) the increase in blood insulin level seen with the infusion of propionate alone. In Expt 2, less severe treatments were imposed, the aim being to reproduce metabolic loads of propionate and ammonia that might be expected from a diet of high-protein grass silage rich in lactic acid. The treatments were a basal diet of grass silage alone or with the following infusions (g/d): NaCl 145, NaCl 145 plus urea 50, propionic acid 200, urea 50 plus propionic acid 200. Effects were less pronounced than in Expt 1 but, in the period immediately after infusion, similar effects were seen. It is concluded that propionate-ammonia interactions may have potentially important effects on milk production especially for diets with high proportions of grass silage containing high levels of protein and lactic acid.

Ammonia↗