Effect of feeding on the diurnal rhythm of plasma cortisol and adrenocorticotrophic hormone concentrations in the pregnant ewe and sheep fetus.

The effects of two different feeding regimes on the 24 h profiles of maternal and fetal plasma cortisol and adrenocorticotrophic hormone (ACTH) concentrations were studied in eight pregnant ewes between 123 and 144 days of gestation. Once daily-fed ewes (n = 4) received 1 kg of lucerne-chaff at 11.00 h, and multi-fed ewes (n = 4) received 100-200 g of lucerne-chaff at 09.00, 11.00 and 13.00 h and then 150 g until 09.00 h the following day. There were significant differences between the two feeding groups in the 24 h profile of maternal plasma osmolality; once daily feeding at 11.00 h was associated with a peak in maternal plasma osmolality at 15.00 h whereas maternal plasma osmolality reached plateau levels at around 17.00 h in the multi-fed group. There were also differences between the two feeding groups in the 24 h profiles of maternal and fetal plasma glucose. Maternal and fetal plasma glucose reached peak concentrations at 19.00 h in the once daily-fed ewes in contrast to the multi-fed group, where a plateau in maternal and fetal plasma glucose was reached between 19.00 h and 09.00 h the following day. A significant diurnal variation in the plasma concentrations of cortisol was present in the once daily-fed ewes from 123 days gestation and in their fetuses after, but not before, 135 days gestation. Plasma cortisol peaked at 11.00 h in the ewes and at 13.00 h in the fetuses of this group. In the once daily-fed group there was also a significant diurnal variation in maternal and fetal plasma ACTH; plasma ACTH concentrations were highest at 11.00 h in the ewes aged between 123 and 144 days and in fetuses after 135 days gestation. In the multi-fed group, whilst ACTH was highest at 09.00 h in the ewes and at 13.00 h in the fetuses, there was no significant diurnal variation in the plasma concentrations of cortisol in the ewes or fetuses of this group at any stage between 123 and 144 days gestation.     

Effect of copper sulphate on alpha-ketoglutarate metabolism in the digestive gland of the snail host, Lymnaealuteola

Significant drop in the size of fuel depots was noted in copper sulphate treated snails. Free amino acid levels dropped and lactate level increased. The effects of copper treatment on rates of fuel oxidation and ammonia production in the presence of exogenously added alpha-ketoglutarate were evaluated. 92% drop in Kg dh complex activity, 33% drop in Alanine amino transferase (ALAT) activity with 78% rise in Glucose-6-phosphatase activity were recorded. Results were discussed in relation to metal ion binding with proteins and its inhibitory effect on alpha Kg dh complex enzyme activity. Molluscicidal activity of copper was found to be due to metabolic block in the TCA cycle at the alpha-ketoglutarate level.     

Kinetics of lactate and glucose metabolism in the pregnant ewe and conceptus

Two monotocous and two ditocous ewes were infused at 124-130 days of gestation with a mixture of L-[U-14C]lactate and D-[6-3H]glucose via a maternal or umbilical catheter, separate days being used for each infusion. Plateaux-specific radioactivities of plasma lactate and glucose were used to derive a four-pool model describing the fluxes between the lactate and glucose pools of the infused conceptus and mother. The average turnover rate of lactate was 23.3 and 13.2 mg carbon min-1 in the conceptus and 32.0 and 44.0 mg carbon min-1 in the mother for monotocous and ditocous ewes, respectively. Glycolysis rates within both conceptus and mother in all sheep were high, accounting for about 80 and 60% of the respective rates of lactate turnover. The synthesis of glucose from lactate accounted for 13 and 31% of the glucose turnover in the mother in monotocous and ditocous ewes, respectively, but was insignificant in the conceptus. Glycolysis within the conceptus used only glucose which had entered and mixed with the conceptus glucose pool; there was no direct transfer of carbon from the maternal glucose pool to the conceptus lactate pool. This finding is an important validation for the use of tracer methods to determine glucose use within the whole conceptus rather than within fetal corporeal tissues alone.     

Origin and distribution of portal blood in the sheep

In sheep, the gastrosplenic and mesenteric veins converge at an angle of about 140° to form the portal vein, which is joined, along its right ventral border, by the gastroduodenal vein. At the porta, right and left branches of the portal vein diverge at an angle of 65–70° to supply separate areas that join along a line between the fossa for the gall bladder, and the middle of the left branch. Right dorsal branches leave the portal vein or its right branch near the point of bifurcation. When ¹³¹I-albumin that had been heated was injected into the right ruminal vein and entered the portal stream in the gastrosplenic vein, no significant differences existed in the levels of radioactivity between the areas supplied by the different portal branches. When the ¹³¹I-albumin entered the portal stream from either the gastroduodenal or mesenteric veins, the area supplied by the right branch contained a significantly higher level of radioactivity than the remainder of the liver. When corrections were made for an unequal distribution of blood, it was found that blood from the gastrosplenic vein was distributed preferentially to the left branch, blood from the gastroduodenal vein to the right branch, and that blood from the mesenteric vein enters the right and left branches in preference to the right dorsal branches of the portal vein.     

Immunoglobulins on the surface of sheep lymphocytes I. Class and cellular distribution

Sheep immunoglobulins were purified and rabbit antisera specific for μ and γ heavy chains and light chains prepared. Lymphocytes obtained by cannulation of the efferent duct of the sheep popliteal node were labeled in vitro with ¹²⁵I-anti-Ig antibodies. The percentage of lymphocytes labeling for μ, γ or light chains, was, in each case, approximately 20 – 25 %, but cells were most heavily-labeled by anti-μ chain and least by anti-γ chain antibodies. As the sum of the proportions of cells labeling for μ and γ chains (total, 40.6 %) greatly exceeded that labeling for light chains (20.4 %), it was concluded that labeled cells had both γ and μ chains exposed on their surfaces, probably as IgG and IgM. Lymphocytes were titrated against anti-μ or anti-γ chain sera and means (± 1 standard deviation) of 19 200 ± 8200 molecules IgG and 14 700 ± 9300 molecules IgM (19 S, or 73 600 ± 46 800 molecules 8 S) were calculated to be exposed on the surface of each cell labeled by anti-Ig antibodies. It is suggested that those cells from the sheep which bound anti-Ig antibodies were bone marrow-derived lymphocytes as has been found in the mouse.     

Major and collateral components of blood flow to pregnant sheep uterus.

In vivo measurements of vessel diameter, latex injections, and acrylic-cast studies indentified the middle uterine arteries as the main source of blood supply to the pregnant sheep uterus. Collateral circulation stemmed from the dorsal uterine arteries, and the ovarian arteries, and small cervical branches derived from the external iliac arteries (in decreasing order of importance). These morphological observations were related to estimates of collateral flow obtained during isolated, in situ perfusion of the pregnant sheep uterus carried out through the cannulated middle uterine arteries. Collateral blood flow was estimated from the shift of the flow-pressure curve produced by inflation of a balloon catheter advanced into the aorta below the renal arteries. Middle uterine artery flow to one horn increased from 162 +/- 23 ml/min in midgestation to 323 +/- 44 ml/min near term. Collateral uterine blood flow did not change significantly: 82 +/- 15 ml/min in midterm, 74 +/- 9 ml/min near term. Collateral flow consituted a larger fraction of inflow to the horn containing the fetus in 9 of 10 single pregnancies.     

Effect of dietary D-penicillamine on metabolism of copper in the rat.

When normal rats were put on a diet containing d-penicillamine equivalent to a dosage of about 1.75 g/day in a 70-kg man, there was a prompt, marked decrease in biliary excretion of copper and of radiocopper after its intravenous administration. Urinary copper increased as tissue copper levels decreased; this decrease was most pronounced in bone marrow, kidney, lung, and spleen. Plasma copper increased and p-phenylendiamine oxidase activity increased. Fecal copper decreased modestly, which was probably attributable to decreases in food intake and biliary copper. Copper-toxic rats, already hypercupriuric, excreted more urinary copper when given d-penicillamine.     

Organ distribution of sheep red blood cells in ALS-treated rats.

The inter-organ distribution of radioactivity in rats injected with 51Cr-labelled SRBC is altered after treatment with ALS absorbed with this antigen. The alteration is due to the presence of soluble SRBC antigens in the serum and subsequent immunization of the tested animals. The 51Cr distribution does not correspond to the uptake of antigenic material in immunized rats.     

Effects of the B-cell activators lipid A and dextran sulphate on the antibody response to sheep red blood cells in piglets.

The in vivo effects of Lipid A and dextran sulphate on the antibody response to the thymus-dependent antigen SRBC in piglets are reported. No alteration of the low primary antibody response was observed with any of the B-cell activators. However, both substances induced an increase in antibody titre after secondary challenge with the antigen, which was shown to be of the IgG class. An activation of immunological memory in the absence of primary antibody response is suggested.     

Correlation of zinc and copper values in the blood serum of Makuii sheep

In autumn 2009, 87 blood samples (28 male and 59 female) were taken, via jugular vein puncture using a heparinised venoject, from Makuii sheep in a preserved herd. The samples were divided into four age groups. Blood samples were transferred to a laboratory on ice, and the serum samples were separated from whole blood by centrifugation. Concentration of zinc and copper was measured in the serum by atomic absorption spectrophotometry. The mean?±?SE of zinc and copper was 8.34?±?1.07 and 12.32?±?0.28?μmol/l, respectively. Zinc values were less than the normal expected range (P?<?0.05), but the copper value was normal in serum samples. It is possible that there is zinc deficiency in the herd in this part of Iran.