ANALYSIS OF THE ROLE OF ENDOGENOUS PROLACTIN ON FLUID AND SODIUM CHLORIDE ABSORPTION BY THE RAT JEJUNUM

1975 ◽  
Vol 67 (3) ◽  
pp. 343-349 ◽  
Author(s):  
J. R. MAINOYA
Keyword(s):  
Sodium Chloride ◽  
Adverse Effects ◽  
Intestinal Absorption ◽  
Rat Jejunum ◽  
Chloride Absorption ◽  
Adrenalectomized Rats ◽  
Intact Rats

SUMMARY Intestinal absorption of fluid and NaCl in rats is significantly decreased after hypophysectomy and increased in rats with pituitary implants. Oestrogen and reserpine significantly stimulate mucosal fluid and NaCl transfer in both normal and adrenalectomized rats, comparable to the effects of administration of prolactin. In intact rats, ergocryptine enhanced intestinal absorption of fluid and NaCl; however, it failed to exert any effects in adrenalectomized rats. Adrenalectomy alone had no adverse effects on intestinal absorption in saline-compensated rats. The administration of corticosterone alone or together with prolactin significantly enhanced intestinal absorption, although the effect of corticosterone alone was more variable. These data strongly suggest that increased endogenous prolactin levels produce stimulatory effects on intestinal absorption of fluid and NaCl by the rat jejunum.

Effect of deoxycorticosterone on sodium appetite of intact and adrenalectomized rats

1965 ◽  
Vol 208 (6) ◽  
pp. 1281-1285 ◽  
Author(s):  
George Wolf
Keyword(s):  
Sodium Chloride ◽  
Low Doses ◽  
Sodium Appetite ◽  
Self Selection ◽  
Saline Preference ◽  
High Doses ◽  
Adrenalectomized Rats ◽  
Stimulation Of ◽  
Intact Rats

The effect of DOC on sodium chloride (saline) intake was studied in intact and adrenalectomized rats under "two-bottle" self-selection conditions. It was found that in adrenalectomized rats low doses of DOC produced a decrease in saline intake (restoration of sodium-retaining ability), whereas high doses produced an increase in saline intake (stimulation of sodium appetite). At high doses, however, intact rats consumed more saline and manifested a greater preference for it than did similarly treated adrenalectomized rats. Treatment with corticosterone increased both absolute saline intake and saline preference of DOC-treated adrenalectomized rats.

THE SECRETION OF ANTIDIURETIC HORMONE IN RESPONSE TO HAEMORRHAGE AND THE FATE OF VASOPRESSIN IN ADRENALECTOMIZED RATS

1954 ◽  
Vol 11 (2) ◽  
pp. 165-176 ◽  
Author(s):  
M. GINSBURG
Keyword(s):  
Body Weight ◽  
Sodium Chloride ◽  
Antidiuretic Hormone ◽  
Intravenous Injection ◽  
Posterior Pituitary ◽  
Arterial Blood ◽  
Adrenalectomized Rats ◽  
Intact Rats

SUMMARY 1. The antidiuretic potency of arterial blood from adrenalectomized rats was greater than that from intact rats, but only if 2 or more ml. of blood were taken from each rat. It is concluded that the amounts of posterior pituitary antidiuretic hormone released during haemorrhage are greater in adrenalectomized than in intact rats. 2. The effect of haemorrhage on the antidiuretic potency of blood in adrenalectomized rats treated with sodium chloride or cortisone was not different from that in intact rats. 3. The disappearance of intravenously injected vasopressin (100 mU/100 g body weight) was retarded after adrenalectomy. Up to 48 hr after adrenalectomy this was due to a reduced capacity of the kidneys to remove vasopressin from the circulation. 4. Treatment with cortisone increased the rate of disappearance of vasopressin in adrenalectomized rats, but the rate was not restored to that observed in intact animals. 5. Treatment with sodium chloride did not affect the rate at which vasopressin was removed from the circulation of adrenalectomized rats. 6. The excretion of an antidiuretic agent in the urine which followed intravenous injection of vasopressin (100 mU/100 g) 48 hr after adrenalectomy was equivalent to 2·1% of the dose. This compared with an excretion of 6·7% of the dose in intact animals.

Role of Saline Consumption in the Prevention of Deoxycorticosterone Hypertension in Rats by Central 6-Hydroxydopamine

1975 ◽  
Vol 48 (4) ◽  
pp. 327-330 ◽  
Author(s):  
P. J. Lewis ◽  
H. J. Dargie ◽  
C. T. Dollery
Keyword(s):  
Sodium Chloride ◽  
Potassium Chloride ◽  
6 Hydroxydopamine ◽  
Intact Rats

1. The mechanism by which pretreatment of rats with intracisternal 6-hydroxydopamine prevents the onset of deoxycorticosterone hypertension has been studied. 2. Rats pretreated with central 6-hydroxydopamine increase their consumption of 0.17 mol/l sodium chloride-0.03 mol/l potassium chloride (‘saline’) less than normal rats when implanted with deoxycorticosterone. 3. Intact rats restricted to the equivalent consumption of saline of rats pretreated with 6-hydroxydopamine develop hypertension despite this restriction. 4. It is suggested that the prevention of deoxycorticosterone hypertension by central 6-hydroxydopamine does not depend on reduced saline consumption.

EFFECT OF ADRENALECTOMY AND CORTICOSTERONE ON THYROID WEIGHT OF GOITROGEN-TREATED RATS. ROLE OF ADRENAL-CORTICOIDS IN THE INSULIN INCREASE OF GOITRE WEIGHT

1974 ◽  
Vol 75 (4) ◽  
pp. 734-747 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia
Keyword(s):  
Insulin Treatment ◽  
High Plasma ◽  
The Other ◽  
Corticosterone Secretion ◽  
Thyroid Glands ◽  
Small Doses ◽  
Tsh Levels ◽  
Adrenalectomized Rats ◽  
Intact Rats

ABSTRACT The administration of insulin to intact rats on a low iodine diet (LID) and KClO4, or KClO4 as well as 6-propyl-2-thiouracil (PTU) increases the weights of the thyroid significantly, as compared to rats on goitrogens alone. However, as shown here, insulin treatment has no effect on the weights of the thyroid of adrenalectomized goitrogen-treated animals. Furthermore, in adrenalectomized rats on small doses of corticosterone the administration of insulin does not alter the weight of the goitre induced by KClO4. On the other hand, adrenalectomized rats on PTU, or KClO4, or PTU + KClO4 develop smaller goitres than intact animals. The administration of corticosterone increases the thyroid weights of intact rats on goitrogens, and augments the weights of the goitres of adrenalectomized rats on PTU to the values found for intact rats on the same goitrogen. The above mentioned changes in thyroid weight cannot usually be accounted for by changes in circulating TSH, as assessed by a rat TSH radioimmunoassay. The present results are consistent with the assumption that the adrenals probably via corticosterone secretion, play an important role in the mechanism by which insulin increases the weight of the thyroid glands of rats on LID + KClO4, or LID + KClO4 + PTU, without affecting the high plasma TSH levels.

INFLUENCE OF REPRODUCTIVE STATE ON INTESTINAL FLUID AND ION TRANSPORT BY THE RAT JEJUNUM, IN RELATION TO THE POSSIBLE CONTRIBUTION OF PROLACTIN

1975 ◽  
Vol 67 (3) ◽  
pp. 351-358 ◽  
Author(s):  
J. R. MAINOYA
Keyword(s):  
Intestinal Absorption ◽  
Sodium Transport ◽  
Intestinal Transport ◽  
Ovariectomized Rats ◽  
Sodium Absorption ◽  
Rat Jejunum ◽  
Hormonal Changes ◽  
Oestrogen Treatment ◽  
Chloride Absorption ◽  
Pregnancy And Lactation

SUMMARY Mucosal fluid, sodium and chloride transfer by the rat jejunum was higher at pro-oestrus and oestrus than at dioestrus. Prolactin enhanced intestinal absorption in dioestrous but not in oestrous rats. Ovariectomy had no significant effect on fluid and sodium absorption but resulted in increased chloride absorption. Oestrogen treatment, however, stimulated fluid and sodium transport without affecting chloride absorption in ovariectomized rats. In contrast, progesterone had no influence on fluid and sodium transport but inhibited chloride absorption. Intestinal absorption of fluid, sodium, chloride, potassium, calcium and magnesium was significantly increased during pregnancy and lactation. The limited effect of 2-Br-αergocryptine in depressing intestinal absorption of fluid and NaCl in both pregnant and lactating rats suggests that hormones other than prolactin are also involved. Lactating rats not suckled for 24 h, or subjected to reduction in the number of pups from eight to three, did not show major changes in intestinal absorption of fluid and NaCl. The present data suggest that increases in intestinal transport during oestrus, pregnancy and lactation are attributable to hormonal changes to which prolactin may make an important contribution.

ANTIDIURETIC ACTIVITY IN THE NEUROHYPOPHYSIS OF RATS AFTER ADRENALECTOMY AND REPLACEMENT THERAPY

1954 ◽  
Vol 10 (3) ◽  
pp. 228-237 ◽  
Author(s):  
C. CAVALLERO ◽  
EMMA DOVA ◽  
L. ROSSI
Keyword(s):  
Sodium Chloride ◽  
Antidiuretic Hormone ◽  
Urine Volume ◽  
Daily Output ◽  
Antidiuretic Activity ◽  
Hormone Content ◽  
Pars Nervosa ◽  
Daily Urine ◽  
Adrenalectomized Rats ◽  
Intact Rats

SUMMARY 1. The content of antidiuretic hormone in the neurohypophysis, the weight of the neurohypophysis and the daily output of urine were studied in the following groups of rats: intact rats which received 2 g NaCl/100 ml. as drinking fluid; adrenalectomized rats; sham-adrenalectomized rats; adrenalectomized rats injected with deoxycorticosterone acetate or aqueous adrenocortical extract, lipo-adrenal extract, cortisone or cortisone and noradrenaline; adrenalectomized rats to which sodium chloride had been administered; and adrenalectomized rats which received both sodium chloride and adrenocortical hormones. 2. The antidiuretic hormone content of the pars nervosa (per mg wet gland) of intact rats to which salt had been given was about half of that of controls without extra salt. There was no significant difference between the mean daily urine volumes of the two series. 3. In adrenalectomized and sham-adrenalectomized rats, 2 days after the operation, the hormone content of the pars nervosa was reduced. In adrenalectomized animals this decrease in antidiuretic activity persisted; in sham-operated rats the antidiuretic activity had increased 5 days after the operation and was fully restored after 7. The daily urine output of the adrenalectomized animals was about one-third of that of intact controls. 4. No significant increase in antidiuretic hormone content of the neurohypophysis occurred when adrenocortical preparations were injected into adrenalectomized rats, but the urine volume of these animals increased. 5. Salt alone, in low or high doses, both orally or subcutaneously administered, increased the amount of antidiuretic principle in the pituitaries of adrenalectomized rats, but control levels were not attained. The daily urine volume of these animals returned to normal. 6. Combined treatment of adrenalectomized rats with salt and adrenocortical extract or cortisone, but not with salt and deoxycorticosterone acetate, led to full restoration of the antidiuretic hormone content of the neurohypophysis. These treatments also produced a rise of the daily urine volume above that of intact controls. 7. In adrenalectomized rats a close relationship was found between the degree to which the various treatments raised the hormone content of the gland and that to which they increased the daily output of urine. 8. The significance of the results is discussed, and the impossibility of drawing conclusions from them about neurohypophysial function in adrenocortical deficiency is stressed.

Nycthemeral rhythms and sodium chloride appetite in rats

1985 ◽  
Vol 249 (3) ◽  
pp. R375-R378 ◽  
Author(s):  
N. E. Rowland ◽  
L. L. Bellush ◽  
M. J. Fregly
Keyword(s):  
Polyethylene Glycol ◽  
Sodium Chloride ◽  
Nacl Solution ◽  
Dark Cycle ◽  
Adrenalectomized Rats ◽  
Intact Rats

Adrenalectomized rats maintained on a 12:12 light-dark cycle drank large amounts of 0.3 M NaCl solution during the night. They showed virtually no NaCl appetite during the day. As a result of their high day natriuresis, the adrenalectomized rats sustained a negative Na+ balance during the day about three times that of controls. This was offset by a correspondingly higher positive Na+ balance at night. In a second experiment in intact rats, the latency to exhibit NaCl appetite during polyethylene glycol-induced hypovolemia was shorter when the treatment was administered in the evening than in the morning. This again demonstrates a relative facilitation of NaCl intake at night and suggests a major nycthemeral interaction with putative physiological stimuli of NaCl appetite.

Blocking effect of naloxone, dihydroergotamine and adrenalectomy in lithium-induced hyperglycaemia and glucose intolerance in the rat

1986 ◽  
Vol 111 (3) ◽  
pp. 342-348 ◽  
Author(s):  
T. Fontela ◽  
O. García Hermida ◽  
J. Gómez-Acebo
Keyword(s):  
Insulin Release ◽  
Blocking Agent ◽  
Blocking Effect ◽  
Opiate Antagonist ◽  
Glucose Levels ◽  
Sympathetic Nervous ◽  
Adrenergic Blocking ◽  
Adrenalectomized Rats ◽  
Intact Rats

Abstract. The direct effect of lithium administration on plasma glucose levels and glucose-induced insulin release, and the role of opioid and amine systems in these effects were examined in rats. Naloxone, an opiate antagonist, and dihydroergotamine, an alpha-adrenergic blocking agent, reversed the hyperglycaemia as well as the inhibition of glucose-stimulated insulin release induced by lithium. In adrenalectomized rats, administration of lithium induced hypoglycaemia and not hyperglycaemia as in the intact rats. The results suggest that the interaction of secreted endorphins with the sympathetic nervous system is the likely cause of the hyperglycaemia and the inhibition of the glucose-stimulated insulin release induced by lithium.

Renal potassium adaptation in the rat: role of glucocorticoids and aldosterone

1984 ◽  
Vol 246 (3) ◽  
pp. F300-F308 ◽  
Author(s):  
W. R. Adam ◽  
G. J. Goland ◽  
R. M. Wellard
Keyword(s):  
Potassium Excretion ◽  
High Potassium ◽  
Variable Effect ◽  
Adrenocortical Hormones ◽  
Potassium Adaptation ◽  
Urinary Potassium ◽  
Conscious Control ◽  
Adrenalectomized Rats ◽  
Intact Rats

This study examines the role of adrenocortical hormones in the kaliuresis following an acute intragastric KCl load in conscious control (CK) and high potassium diet (HK) rats. Adrenalectomy, 1 day before test, reduced K+ excretion by 35% in CK and 60% in HK rats, leading to minimal differences in K excretion between CK and HK. By contrast, spironolactone inhibited K excretion by only 10%. Glucocorticoids (dexamethasone 3-10 micrograms/100 g) increased K+ excretion in adrenalectomized CK and to a greater extent in adrenalectomized HK rats. Aldosterone (3 micrograms/100 g) alone had a variable effect on urinary potassium excretion in adrenalectomized rats. A combination of dexamethasone (3 micrograms/100 g) and aldosterone (3 micrograms/100 g) in adrenalectomized rats induced potassium excretion equivalent to that in intact rats. Adrenalectomized HK rats had a greater kaliuretic response to dexamethasone and aldosterone than CK rats. These results 1) demonstrate a role for glucocorticoids in K+ excretion in HK rats and 2) illustrate the importance of the increased responsiveness to both glucocorticoids and mineralocorticoids in potassium adaptation.

POSSIBLE ROLE OF 5α-ANDROSTANE-3α,17β-DIOL IN THE CONTROL OF FOLLICLE-STIMULATING HORMONE SECRETION IN THE IMMATURE FEMALE RAT

1982 ◽  
Vol 92 (1) ◽  
pp. 37-42 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
P. KRAMER ◽  
L. GRIBLING-HEGGE
Keyword(s):  
Inhibitory Action ◽  
Combined Treatment ◽  
Hormone Secretion ◽  
Inhibitory Effect ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Immature Rat ◽  
Rat Strain ◽  
Intact Rats

A possible role of 5α-androstane-3α,17β-diol (3α-androstanediol) in the control of FSH secretion was studied at various ages in ovariectomized rats. In the rat strain used, vaginal opening, coincident with first ovulation, generally occurs between 37 and 42 days of age. If 3α-androstanediol alone was given as an ovarian substitute, an inhibitory effect on FSH release was evident with all three doses tested (50, 100, 300 μg/100 g body wt) between 13 and 30 days of age; at 33–35 days of age only the 300 μg dose caused some inhibition of FSH release. Results were more complex if 3α-androstanediol was given in combined treatment with oestradiol and progesterone. Given with progesterone, 3α-androstanediol showed a synergistic inhibitory action on FSH release between 20 and 30 days of age. However, when 3α-androstanediol was combined with oestradiol a clear decrease in effect, as compared to the effect of oestradiol alone, was found between 20 and 30 days of age. Also the effect of combined oestradiol and progesterone treatment was greater than the effect of combined treatment with oestradiol, progesterone and 3α-androstanediol. At all ages after day 20 none of the steroid combinations tested was capable of maintaining FSH levels in ovariectomized rats similar to those in intact rats. It is concluded that 3α-androstanediol might play a role in the control of FSH secretion in the immature rat, but after day 20 the potentially inhibitory action of 3α-androstanediol on FSH secretion is limited in the presence of oestradiol.

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