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[Comparison between the blood from orbital sinus and heart in analizing plasma biochemical values--increase of plasma enzyme values in the blood from orbital sinus].

Plasma biochemical values, blood urea nitrogen (BUN), glucose, aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine phosphokinase (CPK), were compared between the samples collected from orbital sinus, heart and tail vein in mice, rats and hamsters. The significant higher values of AST, LDH and CPK were shown in samples from orbital sinus as compared with that from other sites. The blood from orbital sinus was bleeding by two methods and compared in the plasma enzyme values. It is suggested that the leakages of these enzymes from destroyed ocular tissues result in the increase of the plasma enzyme values.

Animals↗

Comparison of immunoreactive renin and plasma renin activity in human plasma.

Measurement of immunoreactive plasma renin concentration (PRC) using direct radioimmunoassay (RIA) was compared with the common procedure, measurement of plasma renin activity (PRA). The sensitivity of the PRC assay was 5 pg/ml. In 67 normal subjects aged 45.2 +/- 1.2 year, the mean PRC value was 17.0 +/- 0.9 pg/ml in the recumbent position and 38.0 +/- 5.4 pg/ml in the upright position. In patients with high renin essential hypertension and renovascular hypertension, discrepancies were observed between changes in PRA and PRC at 60 min after the administration of captopril. In a patient with Bartter's syndrome PRC was markedly elevated (393 pg/ml) and the changes in PRA and in PRC after captopril were very different (452% vs. 1249%). In all 10 cases of primary hyperaldosteronism PRC was less than 5 pg/ml. The correlation coefficient between PRC and PRA was 0.85 (n = 227, p less than 0.01). The slope of the regression line between PRA and PRC decreased in proportion to PRC values. Direct RIA for PRC is likely to be useful for the determination of plasma active renin when renin levels are high or substrate concentrations are abnormal. Moreover, the combined use of PRA and PRC measurements might be useful in assessing abnormalities in renin substrate concentration as well as in PRC.

Adolescent↗

Interrelationships of pituitary and plasma corticotrophin and plasma corticosterone during adrenocortical regeneration in the rat.

Pituitary and plasma ACTH and plasma corticosterone were measured at various times after adrenal enucleation or adrenalectomy. The changes in ACTH could be inversely correlated with those in plasma corticosterone. They could also be prevented by maintenance therapy with the steroid. The results indicate that the corticosteroids control both the release and the synthesis of ACTH but that their effect is predominantly on the release of the hormone.

Adrenal Cortex↗

Failure of fasting and changes in plasma metabolites to affect spontaneous fluctuations in plasma concentrations of ovine placental lactogen.

The relationships between plasma concentrations of energy substrates and placental lactogen (PL) were investigated in pregnant ewes. In successive hourly samples of plasma PL, concentrations varied by +/- 30% but were not related to general activity or feeding of the ewes or the time of day. Fasting ewes for 72 h did not alter the pattern or the mean PL titres. Insulin-induced acute hypoglycaemia, hyperglycaemia and decreases or increases in free fatty acids (FFA) all failed to alter PL levels significantly during 5-h post-treatment periods. These experiments demonstrate that PL secretion in the ewe fluctuates markedly and is unaffected by changes in plasma glucose FFA concentrations.

Acetates↗

Elevated plasma levels of oxytocin in women taking low-dose oral contraceptives. Identification of the plasma oxytocin with high performance liquid chromatography.

The aim of the present study was to investigate whether low-dose oral contraceptives affect oxytocin concentrations in plasma. Twenty women participated in an open cross-over study. Six consecutive blood samples were drawn twice, with a 4-week interval, in the luteal phase of the menstrual cycle when the women were/were not taking oral contraceptives. Plasma levels of oxytocin were analysed with a radio-immunoassay specific for oxytocin. A significant increase in oxytocin concentrations was observed following ingestion of oral contraceptives (p less than 0.02). Women with the highest oxytocin levels during a normal menstrual cycle increased their levels the most when on oral contraceptives. Analysis with high performance liquid chromatography demonstrated that immunoreactive oxytocin found in plasma, whether with or without oral contraceptives, co-eluted with synthetic oxytocin standard. An interesting possibility could be that the mental side effects and effects on glucose metabolism occurring after treatment with oral contraceptives might be related to elevated oxytocin levels, since metabolic and CNS effects of oxytocin are known.

Adult↗

Plasma noradrenaline concentration in hypertensive and normotensive forty-year-old individuals: relationship to plasma renin concentration.

Forty-year-old individuals with labile and with mild sustained essential hypertension, identified during a survey of a population born in 1936, were investigated. None had ever received antihypertensive treatment. In thirty-three individuals (26 M, 7F) with diastolic blood pressure (DBP) greater than or equal to 95 mmHg at the very first examination and in thirty-one (14 M, 17 F) randomly selected normotensive controls plasma noradrenaline concentration (PNAC) was measured at rest supine. In twenty-two patients (16 M, 6 F), with sustained diastolic hypertension (diastolic blood pressure greater than or equal to 95 mmHg on at least three different occasions) and in twenty-four (14 M, 10 F) normotensive controls PNAC and plasma renin concentration (PRC) were measured supine at rest and again 2 h after furosemide and ambulation. Basal and acutely stimulated values for PNAC and PRC were identical in hypertensive and normotensive individuals. A close correlation between PNAC and PRC after acute stimulation (r = 0.77, P < 0.001) as well as between the absolute changes from resting to acutely stimulated values (r = 0.72, P < 0.001) were found in the hypertensive individuals. It is concluded that sympathetic nerve activity, as defined from measurements of plasma noradrenaline concentration, is similar in young patients with mild hypertension and in normotensive controls. We propose that the discrepancies found in the literature might be related to a lack of comparability between hypertensive and normotensive individuals studied, as far as the source of study populations is concerned.

Adult↗

Influence of plasma protease inhibitors and the secretory leucocyte protease inhibitor on leucocyte elastase-induced consumption of selected plasma proteins in vitro in man.

Cleavage of C3, fibronectin, antithrombin III and alpha 2-antiplasmin in human plasma following the addition of increasing amounts of human leucocyte elastase was studied using an in vitro model. The cleavage was correlated with the degree of saturation of the plasma protease inhibitors alpha 2-macroglobulin and alpha 1-protease inhibitor and also with varying amounts of secretory leucocyte protease inhibitor. When alpha 1-protease inhibitor approached saturation, there was a prompt cleavage of all the four plasma proteins studied. The secretory leucocyte protease inhibitor was needed in a concentration of 6 mumol/l in the present model to block this consumption completely. This concentration also gave some protection of alpha 1-protease inhibitor and alpha 2-macroglobulin.

Antithrombin III↗

Effect of chronic infusion of atrial natriuretic factor on plasma and urinary aldosterone, plasma renin activity, blood pressure and sodium excretion in 2-K, 1-C hypertensive rats.

Conscious two-kidney, one-clip (2-K, 1-C) hypertensive rats and their normotensive sham-operated controls were infused during 13 days with synthetic ANF (Arg 101 - Tyr 126) at 35 pmol/hr/rat by means of osmotic minipumps connected to the jugular vein. The initial blood pressure of 186 +/- 6 mmHg maximally decreased to 118 +/- 7 mmHg at day 5 and slowly rose afterwards without reaching basal values. A concomitant drop in pressure natriuresis and diuresis was observed. No changes were observed in ANF-infused sham-operated rats. Urinary aldosterone excretion declined in ANF-treated rats from a basal value of 63.38 +/- 21.04 micrograms/24 hr to 13.36 +/- 3.78 micrograms/24 hr the last infusion day. No change in urinary aldosterone was observed in either non-infused 2-K, 1-C or ANF-infused sham-operated rats. Plasma aldosterone was significantly higher only in non-treated 2-K, 1-C rats. Renal aldosterone clearance was significantly lower in ANF-infused 2-K, 1-C rats than in the other experimental groups. Plasma renin activity (PRA) was lower in treated (3.92 +/- 2.26 AI ng/ml/hr) than in non-treated (9.08 +/- 2.32 AI ng/ml/hr) hypertensive rats, and not different from ANF-infused or non-infused sham-operated rats. No differences in body weight between infused and non-infused rats, or hematocrit between any group were observed. Atrial immunoreactive ANF was not different in any group. These results demonstrate that chronic administration of ANF not only reduces blood pressure and PRA in 2-K, 1-C hypertensive rats but also plasma and urinary aldosterone. Whether the latter is a direct inhibitory effect or secondary to the normalization of PRA is not known. The hypotensive response may be due to a direct effect on vascular smooth muscle but a role of renin cannot be excluded. Because blood pressure returned toward basal values during the last days of the observation period, the possibility of a tachyphylactic effect of ANF on vascular smooth muscle cannot be excluded.

Aldosterone↗

Immunoradiometric assay of active renin in human plasma: comparison with plasma renin activity.

The direct measurement of active renin with monoclonal antibodies (IRMA) in plasma from hypertensive patients was compared with the traditional PRA method. Two monoclonal antibodies were used: 3E8 and 4G1. The first was coupled to magnetizable beads and was used to trap both active and inactive renin from plasma. The second antibody, 4G1, was iodinated and used to detect active renin trapped by 3E8. The correlation coefficient between the two methods was very high (r = 0.98, p less than 0.001) in plasma samples whose PRA values were higher than 2 ng/ml/h; in low renin samples (PRA lower than 2 ng/ml/h) no significant correlation was found (r = 0.12 n.s.). When PRA and IRMA were performed before and after trypsin activation of inactive renin, the percentage of inactive over total renin was 86.8% and 84% as calculated with PRA and IRMA respectively. The direct monoclonal antibodies method for measuring active renin can be usefully adopted, in conjunction with the traditional PRA procedure, in studying both clinical and pathophysiological aspects of the renin-angiotensin system.

Antibodies, Monoclonal↗

Uptake of 5(125I) iodo-2-deoxyuridine (IDU) in plasma and cerebrospinal fluid in a case of herpes encephalitis with a comparative study on the uptake in plasma, cerebrospinal fluid and brain tissue in dogs.

A case of herpes encephalitis diagnosed by brain biopsy and treated with 5-iodo-2-deoxyuridine (IDU) is presented. The infection occurred in a previously well 19-year-old female patient. Plasma and cerebrospinal fluid (CSF) uptake of the substance was determined using 125I labelled IDU. Top CSF levels of IUD and metabolites of less than 4 microgram/ml, about 1/10 of the corresponding plasma level, were obtained after 6 hours of continuous infusion. The result is discussed and compared with a similar study made on 5 healthy beagle dogs where in addition the levels obtained in various parts of the brain were determined. In the animal experiment a mean value of 2.5 microgram/ml of IDU and metabolites was obtained in the CSF after 8 hours, less than 1/20 of the plasma level. The levels in brain tissue were only slightly higher than in the CSF. The causes of therapeutic failures with IDU treatment are discussed.

Adult↗

Plasma concentration of urea, ammonia, glutamine around calving, and the relation of hepatic triglyceride, to plasma ammonia removal and blood acid-base balance.

Two experiments were conducted to test the following two hypotheses: 1) fatty liver could hamper hepatic conversion of ammonia to urea and increase circulating ammonia or Gln% [Gln% = Gln x 100/(Gln + Glu)] in cows around parturition; 2) decreased ureagenesis might cause alkalosis and in turn reduce blood Ca. In the first experiment, 14 Holstein cows were monitored from 27 d prepartum to 35 d postpartum. There was a rise in circulating ammonia and Gln% at calving, suggesting an increase in ammonia passing to and through the liver. Stepwise regression analysis revealed the following relationship for plasma samples at 22 h and liver triglyceride at 2 d postpartum: ammonia (microM) = 32.1+/-0.89 triglyceride (% DM), Gln% = 71.2 + 0.23 triglyceride (% DM) + 1.31 urea (mM). The positive correlation between liver triglyceride and plasma ammonia and Gln% suggests that hepatic triglyceride accumulation might inhibit ureagenesis, thereby increasing ammonia concentration at the perivenous hepatocytes where Gln synthesis occurs and increasing ammonia concentration in blood leaving the liver. In the second experiment, 28 rats were used to determine whether hepatic triglyceride accumulation, induced by choline deficiency, affects urinary ammonia N and blood pH homeostasis. There was a trend for a positive correlation between urinary ammonia N and liver triglyceride. No correlation between liver triglyceride and blood pH, bicarbonate, pCO2 or plasma Ca was found. In conclusion, hepatic triglyceride accumulation may inhibit ureagenesis and result in increased circulating ammonia, Gln% and urinary ammonia N in vivo. Hepatic triglyceride accumulation did not affect blood pH homeostasis.

Acid-Base Equilibrium↗

Amino acids in plasma and duodenal digesta and plasma growth hormone in cows fed varying amounts of protein of differing degradability.

Eighty-four Holstein cows in early lactation fed diets varying in protein percent (11, 14, and 17% crude protein) and degradability in the rumen (normal and heated soybean meal) were sampled for effects on amino acids and growth hormone in blood plasma, and amino acid profiles in the duodenal digesta. Essential and branched chain amino acids in plasma increased as protein and amount of protected protein in the diet increased. These changes were accompanied by decreased concentrations of nonessential amino acids. Plasma growth hormone was highest at low protein (11.3%) probably because of decreased intakes on this diet. Molar percentages of amino acids in duodenal contents were not affected by diet suggesting that our heat-treated soybean meal influenced quantity more than quality of amino acids available for absorption in the small intestines.

Amino Acids↗

Physiological changes in caged layers during a forced molt. 3. Plasma thyroxine, plasma triiodothyronine, adrenal cholesterol, and total adrenal steroids.

The effects of forced molting on plasma levels of thyroxine (T4), triiodothyronine (T3), and adrenal cholesterol and total adrenal steroid content were studied. Commercially available strains of Single Comb White Leghorn (SCWL) hens, reared and maintained under commercial conditions, were used in the three trials. The hens were moved to environmentally modified facilities prior to the forced molt which was accomplished by reducing daylength and by withdrawing feed and water. Egg production ceased within one week of initiation of this procedure. The hens were sampled either daily or an alternate days for up to 22 days beginning at the time of feed removal. Plasma T4 initially decreased upon removal of feed, but increased above control levels by the sixth day of feed withdrawal. Plasma T3 levels remained relatively constant throughout the feed withdrawal period. Resumption of feeding with a fortified ground corn ration resulted in a decrease in T4 and concomitant increase in T3. Changes in adrenal cholesterol and total adrenal steroids were not consistent. However, there was a trend toward increased total adrenal steroids during feed withdrawal, and an increase in adrenal cholesterol upon the resumption of feeding.

Adrenal Cortex Hormones↗

Seminal plasma free amino acids and seminal and blood plasma proteins of the guinea fowl (Numidia meleagris).

Glutamic acid was the major free amino acid in guinea seminal plasma, representing 90.00% of the total amino acids. Threonine comprised 3.74%, aspartic acid 3.23%, and serine 1.50%. Others were detected at less than .50% of the total free amino acids. Blood plasma protein concentration and SE were 2.68 +/- .35 g/100 ml, and the proteins were fractionated by disc acrylamide electrophoresis into seven major bands: albumin, alpha-1, a dense beta fraction, and four postbeta, or gamma, proteins. Seminal plasma protein concentration and SE were .45 +/- .03 g/100 ml, and the proteins separated into nine fractions: albumin, alpha-1 and -2, beta-1, -2, and -3, and three postbeta, or gamma, bands.

Amino Acids↗

Can the creatinine dialysate-to-plasma ratio from the peritoneal equilibration test be replaced by the sodium dialysate-to-plasma ratio and the sodium level in the dialysate?

The peritoneal equilibration test (PET) is a useful tool that categorizes peritoneal transport. However, the method has some inconveniences. Some authors suggest that measuring the sodium level in the dialysate (NaD) or the dialysate-to-plasma ratio for sodium (D/PNa) can substitute for the PET. We applied a mathematical analysis [Fisher intraclass correlation coefficient (FICC)] to 43 PETs performed in 43 peritoneal dialysis patients (29 males, 14 females) with a mean age of 55.3 years (range: 28-85 years). Determinations of NaD, of sodium level in plasma (NaP), and of D/PNa at times 0, 30, 60, 120, and 240 minutes were added to the usual PET determinations. After using the NaD240 and the D/PNa240 values to calculate the cut-off values for the various peritoneal transport categories, we obtained a transport distribution very similar to that of the PET dialysate-to-plasma ratio for creatinine after 240 minutes (D/PCr240). At the same time, the FICC showed good (0.69) and excellent (0.77) correlation of NaD240 and D/PNa240 respectively with the D/PCr240. Therefore either of these two methods, which are cheaper and quicker than a PET, can be used to categorize peritoneal transport with a high degree of reliability.

Adult↗

Effect of palm oil on plasma lipoprotein concentrations and plasma low-density lipoprotein composition in non-human primates.

Palm oil (PO) contains approximately 43% of palmitic acid. It is the most abundant saturated fatty acid in the diet and it is generally considered the primary cholesterol (C)-raising fatty acid. However, the effect of palmitic acid on plasma cholesterol appears to depend on the cholesterol content of the diet. The aim of this study was to determine the effect of PO with either a high-fat, high-C or moderate-fat, moderate-C diet on lipoprotein C and low-density lipoprotein (LDL) composition. Fifty adult, male vervet monkeys were randomly assigned to the high-fat diet group (HFD: 35%E fat, approximately 0.106 mg C/kJ; n = 30) and the moderate-fat diet group (MFD: 30%E fat, approximately 0.027 mg C/kJ; n = 30). Baseline LDL-C, high-density lipoprotein (HDL)-C and body weight were used to stratify the vervets into comparable experimental groups within each dietary group. The HFD group was divided into two groups of 10 each: one group continued with the HFD in which 8.1%E was derived from lard (AF); in the other group, AF was substituted isocalorically with PO. The MFD group was divided into three groups of 10 each: one group continued with the MFD in which 11.8%E was derived from AF; in the other two groups, the AF was substituted isocalorically with either sunflower oil (SO) or PO. This article presents preliminary results on plasma lipoproteins and LDL composition after 6 months of dietary intervention. Plasma total and LDL-C was higher in all the groups, but the mean changes elicited by PO with either the HFD or MFD were no different from that observed with AF and SO. There was no difference in the mean change of LDL molecular weight within the HFD and MFD. It is concluded that PO is no different from AF (HFD and MFD) or SO (MFD) in its cholesterolaemic effect.

Animal Nutritional Physiological Phenomena↗

Plasma lipids in Turkish children: impact of puberty, socioeconomic status, and nutrition on plasma cholesterol and HDL.

In Turkish adults, HDL cholesterol (HDL-C) levels are 10-15 mg/dl lower than those of adults in western Europe and the United States. In this study, we determined whether HDL-C levels in Turks are low from birth to adulthood and assessed the effect of socioeconomic status (SES) on plasma lipids and lipoproteins. Analyses of cord blood from 105 Turkish newborns showed low levels of plasma cholesterol ( approximately 60 mg/dl) and HDL-C (approximately 30 mg/dl), consistent with results from other Western ethnic groups. Prepubescent 8- to 10-year-old Turkish boys and girls of upper (n = 82) and lower (n = 143) SES had high HDL-C levels (50-60 mg/dl) similar to those of western European children. However, the cholesterol (154-158 mg/dl) and HDL-C (55-58 mg/dl) levels of upper SES children were approximately 25 and approximately 12 mg/dl higher, respectively, than those of lower SES children. Height, weight, skinfold thickness, and estimated body fat were greater in the upper SES children and appeared to reflect dietary differences. Upper SES children consumed more total fat (approximately 35% vs. 25% of total calories), including more saturated fat of animal origin, and less carbohydrate (approximately 50% vs. 62% of total calories), consistent with their elevated plasma cholesterol levels. Carbohydrate intake correlated inversely with the HDL-C level. The HDL-C levels in the prepubescent children, especially those of higher SES, who consumed diets more like western Europeans, decreased markedly to adult levels, with males exhibiting a approximately 20 mg/dl decrease (from 58 to 37 mg/dl) and females a approximately 13 mg/dl decrease (from 55 to 42 mg/dl). SES did not affect HDL-C levels in adults. The profound decrease may reflect alterations in androgen/estrogen balance in Turks at puberty and a modulation of hepatic lipase affecting HDL-C levels.

Adult↗

Plasma concentrations, plasma protein binding and residues of sulfamonomethoxine in pigs, horses and cattle.

The protein binding, the plasma half-life and the residue depletion of sulfamonomethoxine (SMM) after intramuscular administration were investigated in pigs, horses and cattle. Protein binding was weakly concentration-dependent. The bound fraction in plasma in the therapeutic range amounted to approximately 45, 40 and 50% for pigs, horses and cattle respectively, and the plasma half-lives were approximately 5.1, 5.7 and 3.1 hours respectively. SMM levels were less than 1 mug/g in muscle tissue after 36, 20 and 12 hours in pigs, horses and cattle respectively. In the kidney SMM levels were not less than 1 mug/g until 48, 60 (extrapolated) and 36 (extrapolated) hours respectively. In pigs and horses SMM residues in the injection site were extremely variable. In cattle, SMM disappearance from the injection site was more regular. SMM concentrations in pig, horse and cattle liver remained more or less constant in the latter part of the period investigated.

Animals↗