DETERMINATION OF ANTIDIURETIC ACTIVITY IN THE RAT FOR STRUCTURAL ANALOGUES OF THE NEUROHYPOPHYSIAL HORMONES

1967 ◽  
Vol 54 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Vladimir Pliška ◽  
Ivan Rychlík
Keyword(s):  
Dose Range ◽  
Precise Determination ◽  
Urine Flow ◽  
Neurohypophysial Hormones ◽  
Antidiuretic Activity ◽  
Antidiuretic Effect ◽  
Lysine Vasopressin ◽  
Structural Analogues ◽  
Determination Of Parameters

ABSTRACT A procedure for measuring the antidiuretic activity of the neurohypophysial hormones and their synthetic structural analogues in the hydrated rat in the dose range of 5–100 antidiuretic microunits is described. The technique of measurement allows the determination of diuresis over one-minute intervals, as well as the total amount of urine excreted over longer periods. The precision of the measurement is greatly increased by the use of a drop divider. The electrical conductivity of the urine is continuously recorded, and the conductivity and creatinine clearance are correlated with the urine flow. These techniques allow the precise determination of parameters such as the half-life of the antidiuretic effect, formal elimination constants, etc.; they can therefore serve for the comparison even of analogues showing qualitative differences in their antidiuretic effects from the chosen standard (arginine or lysine vasopressin), e. g. analogues of the hormonogen type with prolonged effects.

scholarly journals Ideal cycle of combustion engine with natural gas as a fuel

2016 ◽  
Vol 62 (Special Issue) ◽  
pp. S14-S20 ◽  
Author(s):  
I. Vitázek ◽  
J. Klúčik ◽  
J. Jablonický ◽  
P. Vereš
Keyword(s):  
Natural Gas ◽  
Combustion Engine ◽  
Ideal Gas ◽  
Precise Determination ◽  
Combustion Engines ◽  
Compressed Natural Gas ◽  
Working Cycle ◽  
Residual Space ◽  
Determination Of Parameters

The aim of the paper is to present a detailed methodology of calculations of parameters of an ideal working cycle of spark-ignition combustion engine. Natural gas in the form of compressed natural gas (CNG) was used as a fuel. A theoretical ideal cycle is currently described in simplified way. The paper introduces calculations considering excess air, residual space in the cylinder of the engine and the course of properties of gases in dependence on temperature. The thermodynamics of ideal gas mixture was used. A computer program for clear, quick and accurate calculations of this relatively complicated system of relations was designed. The presented methodology of calculations broadens the scope of the theory of combustion engines and enables a precise determination of parameters of combustion engine with natural gas as a fuel.

Effects of vasopressin-glycine and vasopressin-glycine-lysine-arginine on renal function in the rat

1986 ◽  
Vol 108 (2) ◽  
pp. 255-260 ◽  
Author(s):  
C. J. Lote ◽  
A. J. McVicar ◽  
D. G. Smyth
Keyword(s):  
Body Weight ◽  
Filtration Rate ◽  
Urine Osmolality ◽  
Urine Flow ◽  
Control Group ◽  
Precursor Molecule ◽  
Antidiuretic Activity ◽  
Molar Basis ◽  
Lysine Vasopressin ◽  
Vasopressin Receptors

ABSTRACT The peptides vasopressin-Gly and vasopressin-Gly-Lys-Arg occur as part of the sequence of the vasopressin-neurophysin precursor molecule and may be released from the hypothalamus and/or pituitary. [8-Lysine]-vasopressin-Gly (LVP-Gly) and [8-lysine]-vasopressin-Gly-Lys-Arg were administered i.v. to conscious, water-diuretic rats. The renal effects of the peptides were assessed by comparison with the actions of [8-lysine]-vasopressin (LVP) which was administered to separate groups of rats. LVP-Gly and LVP-Gly-Lys-Arg were weakly antidiuretic. LVP-Gly-Lys-Arg was the more potent of the two peptides, but on a molar basis it only had about 10% of the antidiuretic activity of LVP. LVP-Gly and LVP-Gly-Lys-Arg at 10 pmol/h per 100 g body weight (equivalent to the maximal antidiuretic dose of LVP) slightly decreased (P < 0·001) urine flow without causing significant changes in urine osmolality. LVP (10 pmol/h per 100 g body weight) promoted a marked natriuresis (P < 0·001 ) but LVP-Gly and LVP-Gly-Lys-Arg were not natriuretic, even at the dose which was markedly antidiuretic (100 pmol/h per 100 g body weight). Osmolal output decreased at all doses during administration of the extended peptides, but was not significantly changed in the control group or by LVP. Inulin clearance was decreased by about 30% during administration of both LVP and LVP-Gly-Lys-Arg at 100 pmol/h per 100 g body weight. It is concluded that LVP-Gly and LVP-Gly-Lys-Arg show weak antidiuretic activities and that the effect on urine flow may be partly due to a decrease in glomerular filtration rate (GFR). The decrease in osmolal output produced by the peptides is also a likely consequence of an effect on GFR. It is suggested that LVP-Gly and LVP-Gly-Lys-Arg have a low potential for activation of tubular vasopressin receptors, as shown by the weak antidiuretic activity and lack of a natriuretic action, but that they have a relatively stronger action on glomerular vasopressin receptors. J. Endocr. (1986) 108, 255–260

Determination of parameters of short circuit of power transformer by means of mathematical modeling

2017 ◽  
Vol 26 (102) ◽  
pp. 110-119
Author(s):  
D. S. Yarymbash, ◽  
◽  
S. T. Yarymbash, ◽  
T. E. Divchuk, ◽  
D. A. Litvinov
Keyword(s):  
Mathematical Modeling ◽  
Power Transformer ◽  
Short Circuit ◽  
Determination Of Parameters

EFFECTS OF ARGININE-, LYSINE- AND LEUCINE-VASOPRESSIN ON URINARY OSMOLALITY AND RATE OF URINE FLOW IN HYDRATED RATS AND DOGS

1959 ◽  
Vol XXXII (I) ◽  
pp. 134-141 ◽  
Author(s):  
Niels A. Thorn
Keyword(s):  
Arginine Vasopressin ◽  
Urine Osmolality ◽  
Urine Flow ◽  
The Other ◽  
Maximum Increase ◽  
Urinary Osmolality ◽  
Lysine Vasopressin

ABSTRACT Arginine-, lysine- and leucine-vasopressin, injected i. v. into hydrated rats or dogs caused different patterns of response in that urine osmolality fell much more slowly after the maximum increase following arginine-vasopressin, than after the other two preparations. Using 3 different parameters for antidiuretic response, arginine-vasopressin was somewhat more potent than leucine-vasopressin in both rats and dogs, considerably more potent than lysine-vasopressin in rats, and much more so in dogs.

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