Effects of corticotrophin-releasing factor and vasopressin on plasma adrenocorticotrophin molecular forms, aldosterone and corticosterone in young and adult rats and rabbits

1996 ◽  
Vol 8 (1) ◽  
pp. 111 ◽  
Author(s):  
P Pradier ◽  
M Dalle
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Arginine Vasopressin ◽  
Guinea Pigs ◽  
Plasma Corticosterone ◽  
Molecular Forms ◽  
Adult Rats ◽  
Molecular Weights ◽  
Corticotrophin Releasing Factor ◽  
Pituitary Adrenal Axis

Synthetic ovine corticotrophin-releasing factor (CRF) and arginine vasopressin (AVP) were injected alone or in combination (for each peptide 1 microgram/kg body weight) in 7-day-old and adult rats and rabbits. Fifteen minutes after the interscapulary injection, blood was collected for plasma adrenocorticotrophin (ACTH), corticosterone and aldosterone evaluation by RIA. The different circulating forms of ACTH were isolated by Sephadex G50 column chromatography with 1% formic acid and measured by RIA using 1-24 ACTH as standard. Such experiments were previously described in lambs and guinea-pigs using the same schedule. In young and adult rabbits the predominant circulating IR-ACTH form was 'big' ACTH; after stimulation with CRF, AVP or CRF + AVP the 'intermediate' IR-ACTH was greatly increased in adults, but no change was observed in young rabbits. In young and adult rats the predominant circulating form was 'intermediate' ACTH in control and injected animals; ACTH increased after CRF alone or in combination with AVP, but not after AVP alone. In both species the 'intermediate' forms of IR-ACTH were not eluted at the same time by chromatography, and calculated molecular weights were different: 14500 in rats and 9500 in rabbits. Plasma corticosterone and aldosterone were increased in rat and rabbit adults after CRF and AVP; however, they remained unchanged in young rabbits and slightly increased only after CRF in young rats in which corticosterone remained at a very low concentration compared with that in adults. Hence, the pituitary-adrenal axis of 7-day-old rabbits and rats in less reactive than that of sheep and guinea-pig of the same age.

The effects of furosemide and bumetanide on lung liquid production by in vitro lungs from fetal guinea pigs

1990 ◽  
Vol 68 (8) ◽  
pp. 1131-1135 ◽  
Author(s):  
J. Thom ◽  
A. M. Perks
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Loop Diuretics ◽  
Dilution Technique ◽  
Blue Dextran ◽  
Lung Fluid ◽  
Lung Liquid ◽  
Secretion Rates

Lungs from fetal guinea pigs of 61 ± 3 days of gestation were supported in vitro for 3 h, and lung liquid secretion rates were measured by a dye dilution technique based on Blue Dextran 2000. Ten preparations that had received no treatment showed an average secretion rate of 1.12 ± 0.28 mL∙kg−1 body weight∙h−1 during the first hour, and there were no significant changes over the following 2 h. In studies of 54 fetal lungs, furosemide, bumetanide, control ethanol carrier, or saline alone were placed in the supporting medium during the middle hour of the 3-h incubations (ABA design). Furosemide at 10−3 M reduced secretion 83.4 ± 16.8%; at 10−4 and 10−5 M it produced smaller reductions. Bumetanide at 10−3 M usually produced reabsorption (129.9 ± 23.0% reduction), at 10−4 M it reduced secretion 30.9 ± 11.8%, but at 10−5 M it was ineffective. Control carrier and saline were without effect. The ability of the loop diuretics to produce reabsorption of fluid in some preparations suggests the unmasking of an active reabsorptive process. The results also suggest that lung liquid secretion in the fetal guinea pig, as in the sheep, is dependent on a Na+ and Cl− cotransport system.Key words: fetus, lung fluid, bumetanide, furosemide.

EFFECT OF HISTAMINE ON GASTRIC PEPSINOGEN, PEPSIN SECRETION, AND BLOOD PEPSINOGEN IN GUINEA PIGS

1957 ◽  
Vol 35 (1) ◽  
pp. 729-732
Author(s):  
K. Kowalewski
Keyword(s):  
Body Weight ◽  
Gastric Mucosa ◽  
Guinea Pig ◽  
Gastric Juice ◽  
Guinea Pigs ◽  
Gastric Tissue ◽  
Pepsin Secretion ◽  
Enzymatic Function ◽  
Guinea Pig Stomach

The endocrine and exocrine activity of guinea pig stomach was measured by the determination of pepsinogen in gastric tissue and in plasma. Gastric juice pepsin was also studied.A significant increase of both pepsinogen and pepsin was found in animals treated with a dose of histamine (75 mg. per kg. of body weight). These results give further evidence that the zymogenic cells of gastric mucosa may be stimulated by histamine. The determination of pepsinogen in gastric tissue seems to permit a direct approach to the enzymatic function of zymogenic cells.

ON THE ANTIGENICITY OF INSULIN

1957 ◽  
Vol 35 (1) ◽  
pp. 79-92 ◽  
Author(s):  
P. J. Moloney ◽  
L. Goldsmith
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Relative Effectiveness ◽  
Percentage Survival

On the basis of body weight, mice showed a higher percentage survival to large doses of insulin than did rabbits and these in turn were more resistant to insulin than guinea pigs. Antibodies to insulin were induced in five species of animals. Anti-insulins produced by the guinea pig, rabbit, sheep, and horse can each neutralize insulin extracted from the pancreas of the rabbit, sheep, horse, pig, ox, and monkey (Macacus rhesus), but none of the four can neutralize insulin extracted from guinea-pig pancreas. Guinea-pig anti-insulin can neutralize endogenous mouse insulin; horse anti-insulin cannot. The problem of the relative effectiveness of insulin as an antigen is discussed.

scholarly journals Vitamin C status, serum cholesterol levels and bile composition in the pregnant guinea-pig

1980 ◽  
Vol 43 (1) ◽  
pp. 95-100 ◽  
Author(s):  
S. A. Jenkins
Keyword(s):  
Ascorbic Acid ◽  
Body Weight ◽  
Gall Bladder ◽  
Guinea Pig ◽  
Bile Acids ◽  
Serum Cholesterol ◽  
Guinea Pigs ◽  
Cholesterol Content ◽  
Biliary Secretion ◽  
Cholesterol Levels

1. Pregnant guinea-pigs receiving a low dose of L-ascorbic acid (0.2 mg/100 g body-weight per d) developed a hypercholesterolaemia in the third trimester of pregnancy, whereas no change in serum cholesterol levels was observed in pregnant animals receiving a higher dose of the vitamin (2 mg/100 g body-weight per d).2. Pregnancy in the group of guinea-pigs receiving the higher dose of L-ascorbic acid was associated with an increased biliary secretion of bile acids. No change was observed in the biliary secretion of bile acids in pregnant animals receiving the lower dose of L-ascorbic acid, but these animals secreted significantly more cholesterol.3. Changes in the biliary secretion of cholesterol and bile acids in the pregnant guinea-pig according to L-ascorbic acid intake were reflected in the composition of the gall-bladder bile. Thus, the gall-bladder bile of guinea-pigs receiving the lower dose of L-ascorbic acid contained more cholesterol, while the gall-bladder bile of those animals receiving the higher dose of the vitamin had a higher content of bile acids.4. The increased cholesterol content of the gall-bladder of pregnant guinea-pigs receiving the lower dose of L-ascorbic acid resulted in decreased bile acid:cholesterol and phospholipid: cholesterol values, conditions predisposing to cholelithiasis.

Plasma concentrations of adrenocorticotropin-related peptides after corticotropin-releasing hormone and vasopressin injections in sheep

1988 ◽  
Vol 119 (3) ◽  
pp. 391-396 ◽  
Author(s):  
P. Pradier ◽  
M. Dalle ◽  
C. Tournaire ◽  
P. Delost
Keyword(s):  
Body Weight ◽  
Column Chromatography ◽  
Arginine Vasopressin ◽  
Plasma Concentrations ◽  
Molecular Forms ◽  
Pituitary Cells ◽  
Plasma Samples ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Simultaneous Injection

Abstract. Ovine corticotropin-releasing hormone (1 μg/kg body weight) and arginine vasopressin (1 μg/kg) were injected iv in sheep, both separately and in combination. Plasma were sampled just before and 5, 15 and 30 min after the injection. Adrenocorticotropin-related peptides were isolated by Sephadex G-50 column chromatography and measured by RIA. Cortisol and aldosterone were determined on the same plasma samples. Three molecular forms of immunoreactive ACTH (IR-ACTH) were isolated: 'big' (> 20 000 mol wt), 'intermediate' (= 8000 mol wt) and 'little' (= 4500 mol wt). Following CRH injections, the three molecular forms of ACTH were enhanced, particularly the 'little' form, whereas 'intermediate' IR-ACTH was highly and specifically responsive to AVP. After a simultaneous injection of CRH and AVP, additive increases occurred for 'intermediate' and 'little' IR-ACTH. The release of different molecular forms of IR-ACTH after stimulation by CRH or AVP of corticotrope cells suggests that ACTH-related peptides could be stored in different intracellular pools or secreted by different pituitary cells.

scholarly journals Efficacy of Voriconazole in a Guinea Pig Model of Invasive Trichosporonosis

2006 ◽  
Vol 50 (6) ◽  
pp. 2240-2243 ◽  
Author(s):  
Carolina Serena ◽  
Félix Gilgado ◽  
Marçal Mariné ◽  
F. Javier Pastor ◽  
Josep Guarro
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Amphotericin B ◽  
Guinea Pigs ◽  
Systemic Infection ◽  
Pig Model ◽  
Trichosporon Asahii ◽  
Tissue Burden ◽  
Guinea Pig Model

ABSTRACT We have evaluated the efficacy of voriconazole (VRC) in a systemic infection by Trichosporon asahii in immunosuppressed guinea pigs. VRC was more effective than amphotericin B in prolonging survival and reducing tissue burden. The best results were obtained with VRC at 10 mg/kg of body weight/day.

ON THE ANTIGENICITY OF INSULIN

1957 ◽  
Vol 35 (1) ◽  
pp. 79-92 ◽  
Author(s):  
P. J. Moloney ◽  
L. Goldsmith
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Relative Effectiveness ◽  
Percentage Survival

On the basis of body weight, mice showed a higher percentage survival to large doses of insulin than did rabbits and these in turn were more resistant to insulin than guinea pigs. Antibodies to insulin were induced in five species of animals. Anti-insulins produced by the guinea pig, rabbit, sheep, and horse can each neutralize insulin extracted from the pancreas of the rabbit, sheep, horse, pig, ox, and monkey (Macacus rhesus), but none of the four can neutralize insulin extracted from guinea-pig pancreas. Guinea-pig anti-insulin can neutralize endogenous mouse insulin; horse anti-insulin cannot. The problem of the relative effectiveness of insulin as an antigen is discussed.

scholarly journals Species variations in the threshold molecular-weight factor for the biliary excretion of organic anions

1972 ◽  
Vol 129 (5) ◽  
pp. 1071-1077 ◽  
Author(s):  
P. C. Hirom ◽  
P. Millburn ◽  
R. L. Smith ◽  
R. T. Williams
Keyword(s):  
Molecular Weight ◽  
Guinea Pig ◽  
Urinary Excretion ◽  
Intravenous Injection ◽  
Biliary Excretion ◽  
Guinea Pigs ◽  
Organic Anions ◽  
Female Rats ◽  
Weight Factor ◽  
Molecular Weights

1. The excretion in the bile and urine after intravenous injection of 16 organic anions having molecular weights between 355 and 752 was studied in female rats, guinea pigs and rabbits. 2. These compounds were mostly excreted unchanged, except for three of them, which were metabolized to a slight extent (<7% of dose). 3. The rat excreted all the compounds extensively (22–90% of dose) in the bile. 4. In guinea pigs four of the compounds with mol.wt. 355–403 were excreted in the bile to the extent of 7–16% of the dose, four with mol.wt. 407–465 to the extent of 25–44% and eight compounds with mol.wt. 479–752 to the extent of 44–100%. 5. In rabbits four compounds with mol.wt. 355–465 were excreted in the bile to the extent of 1–8% of the dose, two compounds with mol.wt. 479 and 495 to the extent of 24 and 22%, and six compounds with mol.wt. 505–752 to the extent of 31–94%. 6. These results, together with those of other investigations from this laboratory, are discussed and the conclusion is reached that there is a threshold molecular weight for appreciable biliary excretion (i.e. more than 10% of dose) of anions, which varies with species: about 325±50 for the rat, 400±50 for the guinea pig and 475±50 for the rabbit. 7. Anions with molecular weights greater than about 500 are extensively excreted in the bile of all three species. 8. That proportion of the dose of these compounds which is not excreted in the bile is excreted in the urine, and in the three species, bile and urine are complementary excretory pathways, urinary excretion being greatest for the compounds of lowest molecular weight and tending to decrease with increasing molecular weight. 9. Some implications of this interspecies variation in the molecular-weight requirement for extensive biliary excretion are discussed.

EFFECT OF HISTAMINE ON GASTRIC PEPSINOGEN, PEPSIN SECRETION, AND BLOOD PEPSINOGEN IN GUINEA PIGS

1957 ◽  
Vol 35 (9) ◽  
pp. 729-732 ◽  
Author(s):  
K. Kowalewski
Keyword(s):  
Body Weight ◽  
Gastric Mucosa ◽  
Guinea Pig ◽  
Gastric Juice ◽  
Guinea Pigs ◽  
Gastric Tissue ◽  
Pepsin Secretion ◽  
Enzymatic Function ◽  
Guinea Pig Stomach

The endocrine and exocrine activity of guinea pig stomach was measured by the determination of pepsinogen in gastric tissue and in plasma. Gastric juice pepsin was also studied.A significant increase of both pepsinogen and pepsin was found in animals treated with a dose of histamine (75 mg. per kg. of body weight). These results give further evidence that the zymogenic cells of gastric mucosa may be stimulated by histamine. The determination of pepsinogen in gastric tissue seems to permit a direct approach to the enzymatic function of zymogenic cells.

Activation of pituitary-adrenal function in fetal sheep by corticotrophin-releasing factor and arginine vasopressin

1990 ◽  
Vol 124 (1) ◽  
pp. 27-35 ◽  
Author(s):  
A. N. Brooks ◽  
A. White
Keyword(s):  
Negative Feedback ◽  
Arginine Vasopressin ◽  
Plasma Concentrations ◽  
Premature Delivery ◽  
Fetal Sheep ◽  
Feedback Effects ◽  
Adrenal Axis ◽  
Corticotrophin Releasing Factor ◽  
Endogenous Cortisol ◽  
Pituitary Adrenal Axis

ABSTRACT In sheep, birth is preceded by an increase in fetal plasma concentrations of ACTH and cortisol. Activation of the fetal pituitary-adrenal axis is pivotal to the onset of parturition in this species and may be regulated, at least in part, by corticotrophin-releasing factor (CRF). Pulsed administration of CRF has been shown to activate the fetal pituitary-adrenal axis in immature fetal sheep. However, pituitary ACTH responsiveness declined after continued administration of CRF, as a result of increasing negative feedback effects of increased concentrations of endogenous cortisol. To test the hypothesis that arginine vasopressin (AVP) is required, in addition to CRF, to produce the necessary trophic stimulus to the pituitary-adrenal axis, we administered saline, CRF (1 μg), AVP (200 ng) or CRF plus AVP as pulses every 4 h for 7 days to fetal sheep beginning at days 117–120 of pregnancy (term =145 days). Pituitary-adrenal responses were assessed by measuring plasma concentrations of immunoreactive (ir) ACTH and cortisol in response to one of the pulses on each of the 7 days of treatment. On day 1, CRF and AVP significantly increased plasma concentrations of ir-ACTH and there was a synergistic interaction when the two peptides were given together (P<0·05). However, as pulsed treatment continued there was a decline in the pituitary ir-ACTH response to all treatments (P<0·05). This decline in pituitary response occurred over a much longer period of time when CRF and AVP were given together when compared with the two peptides given separately. In contrast, the cortisol response to endogenously released ir-ACTH after administration of CRF, AVP or CRF plus AVP was small on day 1 but gradually increased as treatment progressed. This was particularly apparent when the two peptides were given together. A significant inverse correlation (r = 0·781, P<0·01) between basal cortisol concentrations and the ir-ACTH response to CRF plus AVP was observed over the 7 days of treatment. Premature delivery was not induced by any of the treatments despite significant increases in fetal adrenal weight. Furthermore, there were no changes in the circulating maternal plasma concentrations of progesterone or oestrone during the 7 days of the experiment. We conclude that combination of CRF and AVP administered as pulses to immature fetal sheep results in a greater degree of pituitary-adrenal activation when compared with the two peptides given independently. However, even after this combined treatment regimen pituitary responsiveness eventually declines, an effect which may be due to increased negative feedback effects of increased endogenous cortisol. Journal of Endocrinology (1990) 124, 27–35

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