Energy substrates in bovine oviduct and uterine fluid and blood plasma during the oestrous cycle

Up to 40 percent of cattle embryos die within 3 weeks of fertilization but there is little or no published information on the composition of the oviduct and uterine fluids essential for their survival during this time. We have measured the concentrations of the energy substrates, glucose, lactate, and pyruvate in cattle oviduct fluid on Days 0, 2, 4, and 6 and uterine fluid on Days 6, 8, and 14 of the oestrous cycle and corresponding blood samples. Oviduct and uterine fluids were collected in situ. Glucose concentrations in oviduct and uterine fluids were similar on all days and lower than in plasma (P < 0.05). Oviduct lactate concentration was up to eightfold higher than uterine or plasma concentration (P < 0.01). Oviduct pyruvate concentrations were similar on all days and lower than plasma concentrations on Days 0 and 2 (P < 0.005). Pyruvate concentrations were similar in the uterus and in plasma except on Day 14 when the concentration in plasma was higher (P < 0.05). There were no associations between systemic progesterone or oestradiol and glucose, lactate or pyruvate. There was a linear positive relationship (P < 0.001) between oviduct fluid secretion rate and oviduct glucose concentration and a linear negative relationship (P < 0.001) between oviduct fluid secretion rate and oviduct lactate, but no association between uterine fluid secretion rate and energy substrates. The different concentrations and associations between the energy substrates in oviduct and uterine fluids and blood plasma indicate a differential regulation of the secretion of these energy substrates by the oviduct and uterine epithelium.     

Amino acids in oviduct and uterine fluid and blood plasma during the estrous cycle in the bovine

Up to 40% of cattle embryos die within 3 weeks of fertilization while they are nutritionally dependent on the maternal environment provided by the oviduct and uterine fluids for their development and survival. Despite this dependence there is limited information on the composition of these fluids in cattle. Amino acids are essential for the normal growth and development of the early embryo, acting as precursors of proteins and nucleic acids and as energy sources, osmolytes and signaling molecules. The objective of this study was to measure and compare the amino acid concentrations of oviduct and uterine fluid and blood plasma on different days of the estrous cycle. Oviduct fluid was collected in situ from anaesthetised heifers on Days 0, 2, 3, 4 and 6 and uterine fluid on Days 6, 8 and 14 of the estrous cycle and the concentrations of 19 amino acids determined. Glycine was the most abundant amino acid in both oviduct and uterine fluid. However, the concentrations of many amino acids differed between oviduct and uterus and many were present at higher concentrations in oviduct and uterine fluid than in blood plasma. Oviduct fluid concentrations of amino acids were not affected by day of cycle in contrast to uterine fluid for which there was a day of cycle effect on most of the amino acids. These results provide novel information on the amino acid concentrations in the maternal environment of the early cattle embryo and could form the basis for devising improved media for the production of embryos in vitro.     

Regulation of the elemental composition of the epididymal fluids in the tammar, Macropus eugenii

Micropuncture, microanalytical and microelectrode techniques were used to study electrochemical aspects of 7 elements and fluid in the ductuli efferents and ductus epididymidis of the tammar. Rete testis fluid was isosmotic with blood and had a lower pH. It also contained lower concentrations of bicarbonate, sodium, calcium, magnesium, phosphorus and sulphur and higher concentrations of potassium and chloride than blood. The luminal fluid was acidified further during passage through the sperm ducts and all of the elements which were studied moved in or out of the lumen, usually against an electrochemical gradient. The ductuli efferents reabsorbed 87% of the fluid leaving the testis without changing the intraluminal concentrations of sodium, potassium and calcium, but the concentrations of magnesium, phosphorus and sulphur increased. The caput epididymidis reabsorbed about half the fluid entering it: sodium concentrations decreased and those of potassium and phosphorus increased. There was also some fluid reabsorption and an increase in the values of potassium and phosphorus in the corpus epididymidis. There was little net transport of fluid in the cauda epididymidis; sodium, chloride, magnesium and phosphorus concentrations decreased and potassium values increased. Studies involving filtration through a dialysis membrane of blood and fluid from the rete testis and cauda epididymidis showed that, whilst some of the calcium, magnesium, phosphorus and sulphur was associated with high molecular weight compounds in blood, the association was not significant in the reproductive fluids.     

Continuous collection and analysis of bovine oviduct fluid: preliminary results

Oviduct fluid was collected by cannulating the oviducts of nine cows. The fluid was analyzed for sodium (Na), potassium (K), chlorine (Cl), calcium (Ca), inorganic phosphorus (Pi), magnesium (Mg) concentration and osmolarity (Osm). The mean concentrations +/- the standard error of the means of the constituents were: Na (140.7 +/- 0.37 mEq/L), K (5.12 +/- 0.08 mEq/L), Cl (101.8 +/- 1.54 mEq/L), Ca (1.88 +/- 0.08 mEq/L), Pi (1.97 +/- 0.07 mEq/L), and Mg (1.00 +/- 0.03 mEq/L). Osmolarity was 281.0 +/- 2.56 m Osmols. Significantly lower concentrations of Na (117.4 +/- 2.58 mEq/L) were found in the fluid collected from the oviduct ipsilateral to the ovulating ovary on the day of ovulation. This decrease in Na concentration did not occur in fluid from the contralateral oviduct. The lowest concentrations of Ca were found during days 18 through 21, while the highest were found during days 2 through 6. No significant cyclic changes in the other constituents were observed although the concentrations tended to be highest during days 18 through 21 and lowest on day 1. The concentrations of many of the constituents analyzed were different than those previously reported for bovine oviduct fluid (1).     

THE COMPOSITION OF FLUIDS AND SERA OF SOME MARINE ANIMALS AND OF THE SEA WATER IN WHICH THEY LIVE

1. The electrolyte composition, the pH, and freezing points of the fluids of several invertebrates and one primitive chordate are reported. 2. Fluids of the worms, echinoderms, and the clam Venus were isotonic with sea water; fluids of the Arthropoda were hypertonic to sea water. 3. The pH of all fluids was below that of sea water. In the Arthropoda and Myxine less individual variation in pH appeared than in the echinoderms and worms. 4. Ratios of ionic concentrations in the fluid to those in the sea water indicated (1) uniform distribution of ions between the internal and external media for the echinoderms and Venus, (2) differential distribution of potassium and magnesium in the worms; (3) differential distribution of sulfate, magnesium, potassium, and calcium in the Arthropoda; and (4) differential distribution of calcium, magnesium, and sulfate in Myxine. 5. The unequal distribution of ions implies the expenditure of energy against a concentration gradient across the absorbing or excreting membranes, a capacity frequently overlooked in the invertebrates. 6. The sera of the Arthropoda from diluted sea water showed higher concentrations of sodium, potassium, calcium, and chloride ions relative to the respective concentrations in the external medium than in normal sea water, and also showed different orders for those ions. 7. The increase in osmotic pressure of the sera of the animals moving into brackish water is caused by unequal accumulation of sodium, potassium, calcium, and chloride ions. Sulfate and magnesium ionic ratios do not change.     

Effect of various chloride salts on the utilization of phosphorus, calcium, and magnesium

Only part of the effect of dietary protein on urinary calcium excretion can be ascribed to sulfur amino acids. We hypothesized that chloride, another factor often associated with isolated proteins, and another amino acid, lysine, affect utilization of calcium. The effects of supplemental dietary chloride, inorganic or organic, on calcium, phosphorus, and magnesium utilization were studied in two rat studies. Weanling Sprague-Dawley rats were fed semi-purified diets that contained moderate (1.8 mg Cl/g diet) or supplemental (15.5 mg Cl/g diet) chloride as sodium chloride, potassium chloride, or lysine monohydrochloride with or without calcium carbonate for 56 or 119 days. Rats fed supplemental sodium chloride or potassium chloride had higher urinary phosphorus excretion, more efficient phosphorus absorption, but unchanged tissue phosphorus levels after 7 and 16 weeks of dietary treatment as compared to rats fed moderate chloride. Rats fed supplemental sodium chloride or potassium chloride excreted more calcium in urine at 7 weeks and absorbed calcium less efficiently at 16 weeks. Tissue calcium concentrations were unaffected, but total tibia magnesium and plasma magnesium concentrations were lower in rats fed supplemental sodium chloride or potassium chloride than those fed moderate chloride. Lysine chloride with or without additional calcium elevated urinary calcium excretion even more than sodium chloride and potassium chloride ingestion. Rats fed lysine chloride with supplemental calcium had smaller apparent absorption and urinary losses of phosphorus and magnesium after 16 weeks and lower tibia and plasma magnesium concentrations than rats fed lysine chloride.     

Sodium, potassium, calcium, magnesium, zinc, citrate and chloride content of human prostatic and seminal fluid

The ionic composition of human prostatic fluid varied greatly between individuals, reflecting the secretory activity of the gland and the presence or absence of prostatic inflammatory disease. In normal prostatic fluid the major anion was citrate, while chloride concentrations were lower. Their counterions were mainly sodium and potassium, together with calcium, magnesium and zinc. Prostatic secretions from men with prostatitis comprised mainly sodium and chloride. The electrolytes were closely correlated to each other (except for sodium, which was essentially invariant at about 145 nm). The molar changes per mole of citrate were about 0.52, potassium; -0.53, chloride; 0.17, calcium; 0.14, magnesium; and 0.09, zinc. The pH was also associated with citrate, decreasing from 8.0 to 6.2 as the citrate increased. These various ionic changes can be explained as responses to citrate secretion, without the need to propose specific transport mechanisms for the other ions measured. The marked effect of prostatic inflammation on the composition of prostatic fluid can be seen as being due mainly to decreased secretion rather than active modification.     

Fluid secretion by isolated Malpighian tubules of the housefly Musca domestica

The Malpighian tubules of Musca domestica secrete a fluid with a high concentration of potassium and low concentrations of sodium, calcium, magnesium and chloride compared with the isolating medium.Low secretion rates are produced by low medium potassium concentrations (< 7 mM), with low sodium concentrations (up to 5 mM) increasing secretion; higher potassium concentrations produce higher secretion rates whilst higher sodium concentrations have no further effect. Calcium and magnesium are essential for secretion.The rate of tubule secretion is inversely proportional to the osmotic pressure of the isolating medium and the osmotic pressure of the secreted fluid is slightly hyper-osmotic to the medium over a range of medium osmotic pressures.The metabolic inhibitors cyanide, iodoacetate and 2,4-dinitrophenol inhibit secretion: Cu²⁺ ions, arsenate and ouabain have no effect whereas ethacrynic acid abolishes secretion. 5-hydroxytryptamine, cycle AMP and theophylline have no effect on secretion. Sodium thiocyanate stimulates fluid secretion and increases the osmotic pressure and the concentration of sodium and chloride, but not potassium, in the secreted fluid.     

Ionic composition of the rectal contents and excreta of the reduviid bug Triatoma infestans

We have investigated the chemical composition of the rectal contents, faeces and urine of the blood-sucking bug Triatoma infestans. This is the environment in which the important disease-causing organism, Trypanosoma cruzi, lives. Directly after feeding of Triatoma infestans, the pH of the excreta switched from an acidic to an alkaline pH and, 1 day later, back to a slightly acidic pH. The osmolality varied in the initial excreta and in the rectal contents on the day following the meal between 300 and 460 mosmol/kg H(2)O, but after an additional day it increased to 350-970 mosmol/kg H(2)O. Determinations by ion capillary electrophoresis showed that sulphate and phosphate dominated the rectal contents in unfed bugs. After feeding, the first four drops of fluid excreta were mainly a sodium chloride solution (>150 mM for each). One to 10 days after feeding strong individual variations in the concentrations of individual ions were evident, especially for potassium and sodium. Mean concentrations of chloride remained at about 70 mM; sulphate and phosphate showed an increase within the first 1 or 2 days and then reached a level of about 160 and 210 mM, respectively. The rectal contents of long-term starved bugs contained high concentrations of phosphate and potassium; sulphate and sodium were slightly lower.     

Cations in Hemolymph and Alimentary Tract Tissues of Healthy and Milky Diseased European Chafer (Amphimallon majalis) Larvae

A study was made of certain cations present in hemolymph and alimentary tract tissues of healthy and diseased European chafer larvae and the spores of Bacillus popilliae collected from diseased hemolymph. The major ions found in the hemolymph, in order of decreasing abundance, were potassium, magnesium, sodium, and calcium. Hemolymph of diseased larvae contained relatively higher concentrations of sodium, potassium, magnesium, iron, and zinc than hemolymph of healthy larvae. Concomitantly, the concentrations of ions were lower in the mid-gut and anterior intestinal tissues of diseased larvae. Only sodium decreased slightly in the diseased tissues of the rectum and rectal sac; other ions remained unchanged or increased. Little or no manganese or copper was detected in the hemolymph or tissues. The major cations of spores of B. popilliae were sodium, calcium, and magnesium. Small amounts of potassium, manganese, copper, iron, and zinc were detected in the spores. Based on calcium and dipicolinic acid determinations of the spores, sufficient calcium was found to allow for the formation of calcium dipicolinate in the expected concentrations.     

Visual imaging of ion distribution in human epidermis

The distribution of calcium, magnesium, potassium, sodium, and hydrogen ions in the human epidermis was visualized by blotting to gel containing chemical indicators and the effects of skin barrier disruption were examined. In normal skin, both calcium and magnesium were localized with high concentration in the upper epidermis. EDTA blocked these imaging. The hydrogen ion was also high in the upper epidermis. Sodium did not show obvious gradation in the epidermis. The potassium concentration was the lowest in the upper epidermis. After the barrier disruption, the gradients of calcium, magnesium, and potassium disappeared while the pH gradation was not altered. Observation at a high magnification revealed lower calcium and sodium concentrations in the nucleus. The concentration of magnesium was slightly higher in the nucleus. The novel method of the present study could show the visual image of the ions in frozen tissue without further preparation.     

Ionic regulation in the Antarctic nematode Panagrolaimus davidi,measured using electron probe X-ray microanalysis

The element composition of the pseudocoelomic fluid of the Antarctic nematode Panagrolaimus davidi was analysed by electron probe X-ray microanalysis after absorbing the fluid into Sephadex G-25 beads, and after producing calibration curves by analysing various concentrations of elements of interest absorbed into beads. The nematodes maintain higher concentrations of sodium and potassium in their pseudocoelomic fluid than in the external medium but lower concentrations of magnesium and calcium. When external concentrations of specific ions were elevated there was evidence for the regulation of internal concentrations of sodium, potassium, magnesium and chlorine. The time course of changes in response to exposure to elevated levels of KCl shows an increase in internal concentrations of potassium and chlorine up to 2 h after exposure, followed by a decline. This is consistent with a model of ionic regulation proposed for Caenorhabditis elegans which suggests that high concentrations of ionic osmolytes are replaced by compatible organic osmolytes.     

Variations in the distribution of calcium, magnesium and inorganic phosphorus within chronically catheterized sheep conceptuses during the last eight weeks of pregnancy

The concentrations of calcium, magnesium and inorganic phosphorus were higher in foetal arterial plasma than in maternal jugular plasma in sheep examined between 90 and 145 days of gestation. During the same period the calcium and magnesium concentrations of foetal urine were usually less than amniotic fluid values which in turn were less than maternal plasma concentrations. In allantoic fluid, calcium concentrations were usually less and magnesium concentrations greater than maternal and foetal plasma values. A 2-5 fold increase in the calcium concentrations of allantoic fluid after superfical uterine surgery and in amniotic fluid from a group of foetuses that were exposed during operation, were considered to be artefacts of technique. Inorganic phosphorus concentrations in foetal urine, amniotic fluid and allantoic fluid were variable.     

X-ray micro analyses of cations (Na, K, Ca) and anions (S, P, Cl) in uterine secretions during blastocyst implantation in the rat

The mass changes of sodium, potassium, and calcium ions in the rat uterine secretion at blastocyst delay, activation, and attachment have been estimated with X-ray microanalyses of samples of uterine secretions absorbed by small Sephadex beads. A quantification of the ions was attempted by using a standardized coat of gold on the beads as a reference element for normalization of the ion peaks and by fitting the normalized values into corresponding linear regression equations obtained from measurements of step-wise dilutions of a control rat serum. The concentrations of sodium observed at delay, activation, and attachment were 117, 201, and 203 mEq/l, respectively, and those of potassium were 6, 18, and 19 mEq/l, respectively. Calcium values were about 2 mEq/l and decreased at attachment. Among the anions, only the chloride concentration increased at activation and attachment.     

Effect of salinity stress on organic and mineral constituents in the leaves of pigeonpea (Cajanus cajan L. Var. C-11)

Summary Effects of sodium chloride and sodium sulphate on the content of some organic and inorganic constituents in the leaves of pigeonpea (Cajanus cajan L. Var. C-11) were studied. Increased water content under saline conditions made the leaves succulent. The concentration of reducing sugars appeared to be higher while that of total sugars and starch was lower. The plants also failed to accumulate proline at higher salinity levels. Phosphorus and potassium content were lowered while those of calcium, magnesium, sodium, chloride and sulphate were increase under both salinities. This indicates that there is no regulation on the uptake of latter elements under saline conditions.     

In situ oviduct and uterine pH in cattle

Knowledge of oviduct and uterine pH in cattle is lacking mainly because of the difficulty of accessing these reproductive tissues, which for the oviduct at least necessitates anesthesia. Because halothane anesthesia is known to depress respiratory function and thus increase blood CO2 and decrease pH, oviduct and uterine pH was measured both in the presence and absence of halothane. Using short-term anesthesia with thiopentone only, oviduct pH was measured on days 2-4 of the estrous cycle and uterine pH on days 6 and 8; there was no significant effect of day of the cycle but oviduct pH ( 7.60+/-0.010 ) was greater ( P<0.001 ) than uterine pH ( 6.96+/-0.009 ). Oviduct pH was higher ( P<0.001 ) and uterine pH lower ( P<0.001 ) than venous blood pH ( 7.41+/-0.007 ). Using thiopentone/halothane anesthesia, oviduct pH was measured on days 0, 2, 3, 4 and 6, and uterine pH on days 6, 8 and 14; there was no effect of day of cycle but oviduct pH values were generally higher than uterine values and significantly so ( P<0.001 ) on day 6 where direct comparison was possible. To our knowledge these are the first published in situ measurements of oviduct pH in cattle.     

Microprobe analysis of Na,K, Cl,P, S,Ca, Mg and H2O in frozen-hydrated sections of anterior caeca of the locust, Schistocerca gregaria

Electron probe X-ray microanalysis of frozen-hydrated sections was carried out for sodium, potassium, chlorine, calcium, magnesium, sulphur, phosphorus and water concentrations in the lumen and epithelial cells of freshly-fed adult female desert locusts, and in blood of fed and starved locusts.Sodium and chloride were found to be at a much lower level in the lumen and cells than potassium, and at a much higher level in the blood. The luminal folds were plugged with a dense organic matrix, presumed to be polyanionic glycosaminoglycans, which appeared to restrict access of charged moieties of the absorptive sites. The data were consistent with a model of caecal fluid absorption in which a passive flux of potassium from lumen to blood, possibly assisted by an active absorption of chloride, drives fluid into the blood. Unlike the case of the vertebrate intestine, active absorption of sodium from the lumen would not contribute significantly to the fluid transport in vivo.     

Nitrogen and sulphur requirements of Colletotrichum inamdarii Lal

Summary Nitrogen and sulphur requirements ofColletotrichum inamdarii Lal isolated from the leaves ofCarissa carandas L. have been studied. DL-serine, L-asparagine and L-phenylalanine have been found to be of good nitrogen source followed by potassium nitrate, calcium nitrate, magnesium nitrate, DL-alanine, ammonium nitrate, glutamic acid, ammonium sulphate, DL-valine, aspartic acid, ammonium chloride, ammonium hydrogencarbonate, L-histidine and potassium nitrite. There was no growth in the absence of nitrogen.Sporulation was excellent on calcium nitrate and sodium nitrate, Very good on DL-serine, potassium nitrate, and magnesium nitrate. Good on L-asparagine, L-phenylalanine and ammonium oxalate. Fair on DL-alanine, DL-leucine, ammonium sulphate, DL-valine, ammonium chloride and L-histidine whereas poor on glutamic acid, aspartic acid, ammonium tartarate and ammonium nitrate. Few spores were observed on ammonium hydrogencarbonate but potassium nitrite did not show any sporulation.Amongst the sulphur compounds sodium bisulphate gave the best growth and good sporulation, followed by sodium thiosulphate, magnesium sulphate, ammonium sulphate and potassium sulphate. Thiourea gave negligible growth whereas it failed to grow on zinc sulphate and potassium persulphate.     

Resolution of Pump and Leak Components of Sodium and Potassium Ion Transport in Human Erythrocytes

Further support for the pump-leak concept was obtained. Net transport was resolved into pump and leak components with the cardiac glycoside, ouabain. The specificity of ouabain as a pump inhibitor was demonstrated by its ineffectiveness when the pump was already inhibited by lack of one of the three pump substrates, sodium ion, potassium ion, or adenosine triphosphate. In the presence of ouabain the rates of passive transport of sodium and potassium ions changed almost in proportion to changes in their extracellular concentrations when one ion was exchanged for the other. In the presence of ouabain and at the extracellular concentrations which produced zero net transport, the ratio of potassium ions to sodium ions was 1.2-fold higher inside the cells than outside. This finding was attributed to a residual pump activity of less than 2% of capacity. The permeability to potassium ions was 10% greater than the permeability to sodium ions. A test was made of the independence of pump and leak. Conditions were chosen to change the rate through each pathway separately or in combination. When both pathways were active, net transport was the sum of the rates observed when each acted separately. A ratio of three sodium ions pumped outward per two potassium ions pumped inward was confirmed.     

Cannulation of the equine oviduct and chemical analysis of oviduct fluid

Siliconized rubber tubes were used to cannulate one oviduct in 7 mares, and secretions were collected in a polycarbonate container located externally, in the region of the left paralumbar fossa. Secretion rates were recorded daily during the estrous cycle. Concentrations of calcium, magnesium, sodium, potassium, inorganic phosphorus and glucose were determined in the oviduct fluids secreted throughout the estrous cycle. Secretion rates were greatest during estrus (days 1-9), with a significant decrease (P<.01) noted during nonestrus (days 10-21). Concentrations of all constitutents measured were low during estrus, with a marked elevation in concentration during the nonestrus period. Histologic examination of oviducts following long-term cannulation demonstrated infiltration of lymphocytes, plasma cells, and small areas of degenerated epithelium.