scholarly journals Regulation of maternal ACTH in ovine pregnancy: does progesterone play a role?

2008 ◽  
Vol 295 (4) ◽  
pp. E913-E920 ◽  
Author(s):  
Maureen Keller-Wood ◽  
Charles E. Wood
Keyword(s):  
Plasma Protein ◽  
Plasma Volume ◽  
Plasma Proteins ◽  
Plasma Cortisol ◽  
Protein Concentration ◽  
Adrenocorticotropic Hormone ◽  
Mineralocorticoid Receptors ◽  
Plasma Acth ◽  
Plasma Protein Concentration

Pregnancy is characterized by increased plasma adrenocorticotropic hormone (ACTH) and cortisol. Studies suggest that progesterone acts as an antagonist at mineralocorticoid receptors. Therefore, we tested the hypothesis that chronic progesterone, produced by treatment of nonpregnant ewes or during pregnancy, will result in increased plasma ACTH relative to the plasma cortisol concentrations. We studied three groups of ewes: ovariectomized nonpregnant, nonpregnant treated with progesterone, and pregnant ewes. In two series of studies, ewes were adrenalectomized and replaced with 0.35 mg·kg−1·day−1 or 0.5 mg·kg−1·day−1 cortisol. In both studies, aldosterone was infused at 3 μg·kg−1·day−1. In the first study, additional infusions of cortisol over 24 h were used to increase daily replacement doses to 0.5, 1, or 1.5 mg·kg−1·day−1, and intact pregnant and nonpregnant ewes were studied with infusions of cortisol at 0, 0.5, and 1 mg·kg−1·day−1. In adrenalectomized ewes chronically replaced to 0.35 mg·kg−1·day−1 cortisol, plasma ACTH concentrations were decreased significantly in the nonpregnant progesterone-treated ewes compared with the ovariectomized nonpregnant ewes. With 0.5 mg·kg−1·day−1 cortisol, plasma ACTH levels were greater in pregnant ewes than in nonpregnant ewes with or without progesterone. Overall plasma ACTH levels at 0.35 mg·kg−1·day−1 were significantly related to the plasma protein concentration, suggesting that the ACTH levels in the hypocorticoid ewes are most closely related to plasma volume. Across all steroid doses, ACTH was positively related to plasma proteins and progesterone, and negatively related to cortisol. We conclude that increased progesterone does not alter the feedback relation of cortisol to ACTH, but may modulate ACTH indirectly through plasma volume.

scholarly journals CHANGES IN THE VOLUME OF PLASMA AND ABSOLUTE AMOUNT OF PLASMA PROTEINS IN NEPHRITIS

1924 ◽  
Vol 39 (6) ◽  
pp. 921-929 ◽  
Author(s):  
G. C. Linder ◽  
C. Lundsgaard ◽  
D. D. Van Slyke ◽  
E. Stillman
Keyword(s):  
Plasma Protein ◽  
Plasma Volume ◽  
Plasma Proteins ◽  
Protein Concentration ◽  
The Body ◽  
Absolute Amount ◽  
Low Protein

1. We have not observed gross increases in plasma volume in glomerulonephritis, nephrosis, or nephrosclerosis, even when the concentration of plasma proteins was much below normal. Our results indicate the probability that "hydremic plethora" does not occur. 2. The low protein concentration frequently observed in the plasma in nephritis is not due to increased plasma volume but to a decrease of the total amount of plasma protein in the body. 3. Changes in plasma volume showed no constant relationship to changes in edema.

scholarly journals BLOOD PLASMA PROTEINS AS INFLUENCED BY INTRAVENOUS INJECTION OF GUM ACACIA

1939 ◽  
Vol 70 (6) ◽  
pp. 605-613 ◽  
Author(s):  
Charles L. Yuile ◽  
Ralph E. Knutti
Keyword(s):  
Plasma Protein ◽  
Plasma Proteins ◽  
Protein Concentration ◽  
Fibrinogen Concentration ◽  
Plasma Protein Concentration ◽  
Total Blood ◽  
Gum Acacia ◽  
Normal Limits ◽  
And Function ◽  
Protein Diets

By repeated weekly intravenous injections of gum acacia solution in dogs over periods of 4 to 5 months, it has been possible to maintain plasma protein concentration and total circulating protein at very low levels. If sufficient numbers of such injections are given and then discontinued, plasma protein concentration will remain below the normal limits for several more months. Acacia remains in the blood during this time. Reduction of fibrinogen concentration in such animals is out of proportion to and more marked than the changes in plasma protein concentration. This would indicate interference with liver function. Plasma volume when determined at 7 day intervals during injection periods at first diminishes, then rises 20 to 25 per cent above basal levels. The total blood volume does not show such marked changes because of a decrease in red cell volume. Globulins are reduced to a greater extent than albumin after a single injection of gum acacia, although both albumin and the globulins diminish. This cannot be accounted for by a decrease in fibrinogen alone. After 14 to 16 weekly injections, both albumin and globulins are more profoundly reduced. During injection periods in such animals, it has not been possible to control quantitatively the dietary intake, a complication which has made it difficult to ascertain the effect of various protein diets upon the protein-acacia balance. The changes described, however, have taken place regardless of various types of animal protein diets. Following periods of injection, in spite of very low plasma protein concentration and high acacia concentration in the blood, most of the dogs eat well and therefore they can be used during this period for controlled dietary experiments which may be of value in investigating the mechanism of the production and function of the plasma proteins.

EFFECT OF ADRENOCORTICOTROPIC HORMONE (ACTH) AND CORTISONE ON PROTEINURIA AND HEMATURIA IN THE NEPHROTIC SYNDROME

PEDIATRICS ◽  
1955 ◽  
Vol 15 (1) ◽  
pp. 49-53
Author(s):  
Walter Heymann ◽  
Caroline Gilkey ◽  
Milena Salehar
Keyword(s):  
Nephrotic Syndrome ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Adrenocorticotropic Hormone ◽  
Hormone Treatment ◽  
Oncotic Pressure ◽  
Plasma Protein Concentration

1. Fifteen children suffering from the nephrotic syndrome were treated with 22 courses of either ACTH or cortisone. Three children failed to have a diuresis during 4 courses of treatment. No decrease in proteinuria was noted. Eighteen courses of hormone treatment resulted in diuresis in 12 patients. A decrease in proteinuria preceded diuresis in each instance. [See Table II, Fig. 2 and Fig. 3 in Source Pdf] 2. A relationship between severity of hypoproteinemia and onset of diuresis, once proteinuria has started to decrease, has been established. 3. It is concluded that one of the important actions of ACTH or cortisone in inducing diuresis is concerned with the decrease in proteinuria, resulting in increasing plasma protein concentration and oncotic pressure. 4. The effect of these hormones on hematuria in nephrosis has been noted during 4 courses of treatment. In these proteinuria decreased appreciably. In 4 instances hematuria persisted and proteinuria decreased only slightly or not at all.

scholarly journals THE CONCENTRATION OF THE PLASMA PROTEINS IN NEPHRITIS

1924 ◽  
Vol 39 (6) ◽  
pp. 887-920 ◽  
Author(s):  
G. C. Linder ◽  
C. Lundsgaard ◽  
D. D. Van Slyke
Keyword(s):  
Plasma Protein ◽  
Plasma Proteins ◽  
Protein Concentration ◽  
Total Concentration ◽  
Total Plasma ◽  
Total Protein Concentration ◽  
Plasma Protein Concentration ◽  
Absolute Increase ◽  
Sharp Difference

In nephrosclerosis (Volhard and Fahr classification of nephritis) there was no decrease in the plasma proteins. With heart failure the ratio of albumin to globulin fell from the normal 1.7 ± 0.3 to about 1. There is a sharp difference between the two types of glomerulonephritis in the effect on plasma proteins. In the vascular-interstitial type the effect was the same as in nephrosclerosis. There was no decrease in the plasma proteins until shortly before death. In the glomerulotubular or nephrotic type, active or recently active, the total plasma proteins were less than 5 gm. per 100 cc. This decrease from the normal 5.5 to 7.5 occurred whether edema was present or absent. The decrease affected chiefly the albumin, the globulin being usually diminished but little, and sometimes slightly increased. Consequently the ratio of albumin to globulin was reduced to less than 1, and occasionally to 0.6. In nephrosis similar changes were found in the total protein concentration but in severe cases the decrease in albumin was greater than in nephrotic glomerulonephritis while the globulin was either very slightly reduced or was increased. The albumin : globulin ratio was therefore lower than in nephrotic glomerulonephritis, ranging down to 0.26. With the disappearance of edema there was usually an increase in the plasma protein concentration, but this was not invariable, and concentrations of 4.5 per cent or less were compatible with the persistent absence of edema. The ratio of albumin to globulin showed an irregular tendency to rise. Whenever the total concentration was less than 4 per cent there was some edema present, but it was sometimes slight in amount. With recovery in acute cases, and remission with decrease of proteinuria in chronic cases, normal concentrations were regained. The albumin : globulin ratio remained low in some instances for a longer period on account of an absolute increase in globulin concentration. In "functional proteinuria" no change in plasma proteins was found. Low plasma protein concentrations were always associated with considerable losses of protein in the urine, but these losses did not provide an explanation for all our observations. A disturbance in the production of the plasma proteins appears probable.

scholarly journals PROTEINURIA RELATED TO HYPERPROTEINEMIA IN DOGS FOLLOWING PLASMA GIVEN PARENTERALLY

1948 ◽  
Vol 87 (6) ◽  
pp. 561-573 ◽  
Author(s):  
Roger Terry ◽  
David R. Hawkins ◽  
Edwin H. Church ◽  
G. H. Whipple
Keyword(s):  
Plasma Protein ◽  
Plasma Proteins ◽  
Protein Concentration ◽  
The Body ◽  
Plasma Protein Concentration ◽  
Renal Threshold ◽  
Dog Plasma ◽  
Maximal Output ◽  
Plasma Protein Level ◽  
At Will

Proteinuria in normal dogs can be produced at will by parenteral injections of dog plasma. As the plasma injections are continued the plasma protein concentration rises and at some point protein begins to appear in the urine. The level of plasma protein concentration at which proteinuria appears in normal dogs ranges from 9.6 to 10.4 gm. per cent. This may be termed the renal threshold for proteinuria. Repeat experiments in the same dog show threshold levels to be practically identical. An interval of days (4 to 26 days) has been noted between the start of plasma protein injections and the appearance of the proteinuria. Larger doses of plasma shorten this interval and the critical plasma protein level is attained sooner. Considerable amounts of protein may appear in the urine—298 gm. protein during a 52 day period in one instance studied—yet the urine clears in 1 to 4 days after cessation of protein injections. Autopsy shows undamaged kidneys. Maximal levels of plasma protein concentration range from 10.0 to 11.5 gm. per cent. The highest levels are usually associated with maximal output of protein in the urine. It seems clear that plasma proteins readily pass cell barriers (or membranes) within the body, including the endothelium and epithelium of the renal glomerulus.

Acid-base effects of altering plasma protein concentration in human blood in vitro

1986 ◽  
Vol 61 (6) ◽  
pp. 2260-2265 ◽  
Author(s):  
T. H. Rossing ◽  
N. Maffeo ◽  
V. Fencl
Keyword(s):  
Plasma Protein ◽  
Human Blood ◽  
Plasma Proteins ◽  
Protein Concentration ◽  
Albumin Concentration ◽  
High Concentration ◽  
Acid Base ◽  
Plasma Protein Concentration ◽  
Minor Variation

We altered the concentration of plasma proteins in human blood in vitro by adding solutions with [Na+], [K+], and [Cl-] resembling those in normal blood plasma, either protein-free or with a high concentration of human albumin. After equilibrating the samples with a gas containing 5% CO2-12% O2–83% N2 at 37 degrees C, we measured pH, PCO2, and PO2; in separated plasma, we determined the concentrations of total plasma proteins and albumin and of the completely dissociated electrolytes (strong cations Na+, K+, Mg2+ and anions Cl-, citrate3-). With PCO2 nearly constant (mean = 35.5 Torr; coefficient of variation = 0.02), lowering plasma protein concentration produced a metabolic alkalosis, whereas increasing plasma albumin concentration gave rise to a metabolic acidosis. These acid-base disturbances occurred independently of a minor variation in the balance between the sums of strong cations and anions. We quantified the dependence of several acid-base variables in plasma on albumin (or total protein) concentration. Normal plasma proteins are weak nonvolatile acids. Although their concentration is not regulated as part of acid-base homeostasis, hypoproteinemia and hyperalbuminemia per se produce alkalosis and acidosis, respectively.

Effects of hypoproteinemia on fluid volumes and arterial pressure

1983 ◽  
Vol 245 (2) ◽  
pp. H284-H293 ◽  
Author(s):  
R. D. Manning ◽  
A. C. Guyton
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Blood Volume ◽  
Plasma Protein ◽  
Plasma Volume ◽  
Protein Concentration ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Protein Concentration

The effects of both moderate and large decreases in plasma protein concentration on arterial pressure and fluid volumes were studied in 23 conscious dogs. In experiment 1, plasma protein concentration decreased 33% during a 5-day plasmapheresis period. During this time sodium space increased 11%, mean arterial pressure decreased slightly, and neither blood volume nor plasma volume decreased. Experiment 2 was performed to see if blockade of the alpha-sympathetic and angiotensin systems could prevent the blood volume homeostasis during moderate hypoproteinemia. Sodium space increased; however, blood volume was unchanged. During experiment 3 plasma protein concentration decreased 68% over a 12-day plasmapheresis period. By the last day of plasmapheresis, plasma protein concentration was 2.4 g/100 ml, mean arterial pressure had decreased 26 mmHg, sodium space had increased 12%, plasma renin activity had increased 11-fold, and blood volume and plasma volume were 63.9 +/- 4.0 and 66.9 +/- 2.5% of control, respectively. We conclude that the maintenance of a normal blood volume during moderate hypoproteinemia does not require active participation of the renin-angiotensin and alpha-sympathetic systems and large decreases in plasma protein concentration are accompanied by marked hypovolemia, hypotension, and hyperreninemia.

scholarly journals PARENTERAL PLASMA PROTEIN MAINTAINS NITROGEN EQUILIBRIUM OVER LONG PERIODS

1948 ◽  
Vol 87 (6) ◽  
pp. 547-559 ◽  
Author(s):  
Roger Terry ◽  
William E. Sandrock ◽  
Robert E. Nye ◽  
G. H. Whipple
Keyword(s):  
Plasma Protein ◽  
Plasma Proteins ◽  
Protein Concentration ◽  
The Body ◽  
Plasma Protein Concentration ◽  
Renal Threshold ◽  
Dog Plasma ◽  
Maximal Output ◽  
Plasma Protein Level ◽  
At Will

Proteinuria in normal dogs can be produced at will by parenteral injections of dog plasma. As the plasma injections are continued the plasma protein concentration rises and at some point protein begins to appear in the urine. The level of plasma protein concentration at which proteinuria appears in normal dogs ranges from 9.6 to 10.4 gm. per cent. This may be termed the renal threshold for proteinuria. Repeat experiments in the same dog show threshold levels to be practically identical. An interval of days (4 to 26 days) has been noted between the start of plasma protein injections and the appearance of the proteinuria. Larger doses of plasma shorten this interval and the critical plasma protein level is attained sooner. Considerable amounts of protein may appear in the urine—298 gm. protein during a 52 day period in one instance studied—yet the urine clears in 1 to 4 days after cessation of protein injections. Autopsy shows undamaged kidneys. Maximal levels of plasma protein concentration range from 10.0 to 11.5 gm. per cent. The highest levels are usually associated with maximal output of protein in the urine. It seems clear that plasma proteins readily pass cell barriers (or membranes) within the body, including the endothelium and epithelium of the renal glomerulus.

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