Water Uptake and Moulting in Bufo Regularis Reuss

1951 ◽  
Vol 28 (3) ◽  
pp. 369-373 ◽  
Author(s):  
R. F. EWER
Keyword(s):  
Water Uptake ◽  
Urine Flow ◽  
Posterior Pituitary

1. In Bufo regularis Reuss moulting is accompanied by an increase in the rate of water uptake through the skin. An increase in urine flow is also observed, starting some time after the rate of water uptake has begun to increase. 2. No increase in rate of water uptake occurs following thyroxine feeding on 4 successive days. 3. The possibility that posterior pituitary activity is responsible for the observed increase in rate of water uptake during moulting is discussed.

scholarly journals The Effect of Pitressin and Pitocin on Water Balance in Bufo Regularis Reuss

1951 ◽  
Vol 28 (3) ◽  
pp. 374-384
Author(s):  
R. F. EWER
Keyword(s):  
Water Balance ◽  
Water Absorption ◽  
Water Uptake ◽  
Marked Decrease ◽  
Urine Flow ◽  
Diuretic Effect ◽  
Posterior Pituitary ◽  
Antagonistic Action ◽  
Diuretic Action ◽  
Main Factor

1. In Bufo regularis the injection of either pitressin or pitocin is followed by an increase in the rate of water absorption through the skin, together with a marked decrease in urine flow. The response to pitressin is greater than that to pitocin. 2. The effect of pitocin in increasing water uptake can be attributed to the activity of the 5-10% of the pressor fraction which it contains. 3. A mixture of pitressin and pitocin has the same effect on water balance as a corresponding dose of pituitrin. Pitressin alone has a greater anti-diuretic effect than it has when pitocin is added. 4. Taking into account the antagonistic action of pitocin to pitressin it is possible to account for the anti-diuretic action of pitocin in terms of its pressor fraction content. 5. It is concluded that the pressor fraction is the main factor responsible for both the dermal and the renal components of the water-balance effect produced in B. regularis by injection of mammalian posterior pituitary extracts. This conclusion is discussed in relation to the findings of other workers.

Influence of neurohypophysectomy on the renal actions of aldosterone in the adrenalectomized rat

1990 ◽  
Vol 122 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Cephas T. Musabayane ◽  
Martyn J. Brimble ◽  
Richard J. Balment ◽  
Lesley P. Kelly
Keyword(s):  
Adrenal Gland ◽  
Urine Flow ◽  
Posterior Pituitary ◽  
Observable Effect ◽  
Adrenal Steroid ◽  
Hypotonic Saline ◽  
Gland Function ◽  
Low Rate ◽  
Adrenalectomized Rats

Abstract. The influence of aldosterone administration on urine flow, Na+ and K+ excretion was examined in hypotonic saline infused, Inactin® anesthetised rats following removal of the adrenals or adrenals and posterior pituitary. Plasma adrenal steroid levels were considerably depressed but still detectable 10-14 days after adrenalectomy. Removal of the posterior pituitary markedly reduced Na+ excretion in adrenalectomized animals implying that Na+ retention following neurohypophysectomy is not dependent on adrenal gland function. In adrenalectomized rats aldosterone administration at 42 pmol/min reduced Na+ excretion and urine flow without significantly changing K+ excretion, though plasma K+ was reduced. In adrenalectomized/neurohypophysectomized rats aldosterone further reduced the already low rate of Na+ excretion and increased K+ excretion, though there was no observable effect on urine flow. The results obtained indicate that the Na+-retaining actions of aldosterone are largely independent of posterior pituitary influence. The K+-losing action of aldosterone was, however, only observed in animals in which the posterior pituitary was absent.

THE ACTION AND FATE OF VASOPRESSIN IN NEWBORN AND INFANT RATS

1952 ◽  
Vol 8 (3) ◽  
pp. 214-223 ◽  
Author(s):  
H. HELLER
Keyword(s):  
Body Weight ◽  
Inhibitory Effect ◽  
Urine Flow ◽  
Postnatal Life ◽  
Posterior Pituitary ◽  
Newborn Rats ◽  
Infant Rats ◽  
Antidiuretic Effect ◽  
Diuretic Response ◽  
Response To Water

Estimations of urine volumes and inulin U/P ratios in newborn rats after the administration of 4·5 ml. water and 10 mU. vasopressin/100 g. body weight failed to show an antidiuretic response comparable to that produced in adult controls. When body surface was chosen as the basis of dosage, relatively larger amounts of water were given to newborn rats. These produced an increase in the rate of urine flow (which, however, still remained well below the adult level), but an inhibitory effect of vasopressin again could not be demonstrated. Experiments on older rats (up to 4 weeks of age) showed that an antidiuretic effect of vasopressin comparable to that of adults develops only after several weeks of postnatal life, approximately at the same time as a full diuretic response to water could be obtained. When 10 mU. vasopressin/100 g. body weight was injected both adult and newborn rats excreted about 10% of this dose. It is suggested that vasopressin acts less effectively in newborn rats because for some time after birth the kidney is less responsive to the posterior pituitary antidiuretic hormone than in adults.

The Effects of Posterior Pituitary Extracts on Water Balance in Bufo Carens and Xenopus Laevis, together with some General Considerations of Anuran Water Economy

1952 ◽  
Vol 29 (3) ◽  
pp. 429-439
Author(s):  
R. F. EWER
Keyword(s):  
Water Balance ◽  
Xenopus Laevis ◽  
Water Uptake ◽  
Seasonal Variations ◽  
Biological Significance ◽  
Weight Increase ◽  
Posterior Pituitary ◽  
Large Weight ◽  
Water Economy ◽  
Diuretic Response

1. The effects of pitressin and pitocin on water balance in Bufo carens and Xenopus laevis have been investigated. Bufo carens is most sensitive to pitressin, and shows an increased water uptake together with a well-marked anti-diuretic response. Xenopus reacts equally to the two extracts by an increase in water uptake, but there is no anti-diuresis. 2. The effects of pitressin and pitocin in causing lymph accumulation and resorbtion of fluid from the bladder have been studied in Bufo regularis. Pitressin has the greater effect, and there are indications of seasonal variations in the magnitude of the response. 3. The normal rates of water uptake of B. regularis, B. carens and Xenopus laevis have been measured. The two species of Bufo take up water rapidly, but Xenopus does so much more slowly. After desiccation the water uptake of Bufo regularis increases very considerably. This does not occur in Xenopus. 4. There is a large weight increase after injection of posterior pituitary extracts in Bufo regularis and B. carens, but not in Xenopus laevis. The findings of other workers on the magnitude of the weight increase after posterior pituitary injections are summarized. 5. The results are discussed in relation to the identity of the active principles of the anuran posterior pituitary and to the biological significance of the responses.

The Effect of Pituitrin Injection on the Water Balance of Bufo Regularis Reuss

1950 ◽  
Vol 27 (1) ◽  
pp. 40-49
Author(s):  
R. F. EWER
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Water Uptake ◽  
Lymphatic System ◽  
Biological Significance ◽  
Body Water ◽  
Urine Flow ◽  
The Body ◽  
Excess Water

1. A method of cannulating the cloaca of Anura is described. 2. Using this method it is found that in Bufo regularis the increase in body water which follows pituitrin injection is the result of an increased rate of water uptake, together with a diminished urine flow. 3. The excess water is mostly retained in the lymph spaces, while the water content of the tissues of the body increases very little. 4. The bearing of these results on the problem of the identification of the substance or substances which elicit the amphibian water balance effect, and the biological significance of the organization of the anuran lymphatic system are discussed.

Water uptake by substituted amylose tablets: experimentation and numerical simulation

2009 ◽  
Vol 00 (00) ◽  
pp. 090904073309027-8
Author(s):  
H.W. Wang ◽  
S. Kyriacos ◽  
L. Cartilier
Keyword(s):  
Numerical Simulation ◽  
Water Uptake

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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