PITUITARY AND BLOOD CORTICOTROPHIN CHANGES IN ADRENALECTOMIZED RATS MAINTAINED ON PHYSIOLOGICAL DOSES OF CORTICOSTEROIDS

1962 ◽  
Vol 39 (1) ◽  
pp. 79-86 ◽  
Author(s):  
J. R. Hodges ◽  
Joan Vernikos-Danellis
Keyword(s):  
Ascorbic Acid ◽  
Pituitary Gland ◽  
Replacement Therapy ◽  
Daily Treatment ◽  
Mild Stress ◽  
Acid Control ◽  
Small Doses ◽  
Response To Stress ◽  
Adrenalectomized Rats

ABSTRACT Pituitary and blood corticotrophin (ACTH) concentrations were estimated in adrenalectomized rats maintained on cortisol or crude adrenocortical extract (ACE) with and without ascorbic acid. Blood ACTH levels were also determined in similarly treated animals after subjection to mild stress. Thirty days after adrenalectomy there were marked rises in pituitary and blood corticotrophin concentration which were prevented by daily treatment with small doses of cortisol or ACE. In contrast to intact animals, adrenalectomized rats exhibited markedly increased adrenocorticotrophic responses to mild stress. This pituitary hyperexcitability was not diminished by replacement therapy with corticoids alone but was considerably reduced by ascorbic acid given in conjunction with ACE. It is suggested that corticoids control the rate at which ACTH is synthesised in the pituitary gland and that other factors, including ascorbic acid, control the excitability of the pituitary gland in its adrenocorticotrophic response to stress.

Relationship between endogenous opioids and the oestrous cycle in the rat

1984 ◽  
Vol 100 (3) ◽  
pp. 271-275 ◽  
Author(s):  
G. K. Hulse ◽  
G. J. Coleman ◽  
D. L. Copolov ◽  
J. A. Clements
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Ovarian Hormones ◽  
Endogenous Opioids ◽  
Anterior Pituitary Gland ◽  
Oestrous Cycle ◽  
Neurointermediate Lobe ◽  
Response To Stress ◽  
Induced Changes

ABSTRACT The aim of this study was twofold: (1) to document changes in levels of immunoreactive β-endorphin (Ir-β-EP) in the hypothalamus, anterior pituitary gland, neurointermediate lobe and plasma during the oestrous cycle of the rat and (2) to investigate stress-induced changes in plasma Ir-β-EP at different stages of the oestrous cycle. Evidence was found that Ir-β-EP levels in the hypothalamus, anterior pituitary gland and plasma are not constant during the oestrous cycle and that the Ir-β-EP response to stress is a function of the phase of the oestrous cycle at which stress is applied. It is suggested that fluctuations in ovarian hormones may influence oestrous Ir-β-EP levels both under normal conditions and after exposure to stress. J. Endocr. (1984) 100, 271–275

scholarly journals Effect of the ascorbic acid treatment on the NADHd-positive myenteric neurons of diabetic rats proximal colon

2007 ◽  
Vol 50 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Jacqueline Nelisis Zanoni ◽  
Renata Virginia Fernandes Pereira ◽  
Priscila de Freitas
Keyword(s):  
Ascorbic Acid ◽  
Acid Treatment ◽  
Neuroprotective Effect ◽  
Proximal Colon ◽  
Diabetic Rats ◽  
Daily Treatment ◽  
Body Area ◽  
Neuronal Density ◽  
Myenteric Neurons ◽  
Intestinal Segments

The aim of this work was to study the effect of the ascorbic acid on the myenteric neurons of diabetic rats proximal colon. Fifteen rats (90 days old) were divided into three groups: control, untreated diabetic and treated diabetic with ascorbic acid (DA). After 120 days of daily treatment with ascorbic acid, the intestinal segments were submitted to the NADH-diaphorase (NADHd) histochemistry technique to expose the myenteric neurons. The group DA showed a higher neuronal density (33.4 %) when compared to the untreated diabetic animals (p < 0.05). Cellular body area of neurons was significantly larger in group DA (17.3 %) when compared to the untreated diabetics (p < 0.05). It could be concluded that the ascorbic acid promoted a neuroprotective effect on the NADHd myenteric neurons of the proximal colon of diabetic rats.

Effects of intrahypothalamic crystalline steroids on acute ACTH secretion

1963 ◽  
Vol 205 (4) ◽  
pp. 671-673 ◽  
Author(s):  
Israel Chowers ◽  
Shaul Feldman ◽  
Julian M. Davidson
Keyword(s):  
Ascorbic Acid ◽  
Pituitary Gland ◽  
Median Eminence ◽  
Acute Stress ◽  
Testosterone Propionate ◽  
Experimental Period ◽  
Male Rats ◽  
Acth Secretion ◽  
Unilateral Adrenalectomy ◽  
Cortisol Implants

The respective roles of the hypothalamus and pituitary gland, in the inhibition of adrenocorticotropin secretion by corticoids, were studied by implanting small quantities of crystalline cortisol acetate in the median eminence region and pituitary of male rats. Adrenal weights and adrenal ascorbic acid depletion (AAAD) in response to the acute stress of unilateral adrenalectomy were measured 5, 10, 13, or 21 days postoperatively. Ten days following implantation in the hypothalamus, rats showed adrenal atrophy and inhibition of AAAD. Normal AAAD and slight adrenal hypertrophy were found 10 days after similar implantation of testosterone propionate in the median eminence. Animals with cortisol implants in the pituitary had normal adrenal weights and AAAD responses at this time. In rats with cortisol implants in the hypothalamus, an inhibition of AAAD was present after 5–6 days, had increased maximally at 13 days, and returned to normal at 21 days. Adrenal atrophy, however, was first noted at 10 days and adrenal weight continued to decline throughout the experimental period.

THE ADRENAL ASCORBIC ACID-DEPLETING CAPACITY OF EXTRACTS OF THE INFANT RAT PITUITARY GLAND

Endocrinology ◽  
1955 ◽  
Vol 56 (3) ◽  
pp. 341-344 ◽  
Author(s):  
A. P. RlNFRET ◽  
S. HANK
Keyword(s):  
Ascorbic Acid ◽  
Pituitary Gland ◽  
Infant Rat ◽  
Rat Pituitary

FURTHER STUDIES ON THYROID - ADRENAL - ASCORBIC ACID RELATIONS IN ANIMALS EXPOSED TO COLD

1956 ◽  
Vol 34 (1) ◽  
pp. 1251-1260 ◽  
Author(s):  
André DesMarais
Keyword(s):  
Ascorbic Acid ◽  
Thyroid Hormones ◽  
Deleterious Effect ◽  
Low Doses ◽  
Growth And Survival ◽  
Beneficial Effects ◽  
Alarm Reaction ◽  
Different Doses ◽  
Adrenalectomized Rats

The effect of ascorbate administration on resistance to cold and thyroid function was studied in adrenalectomized rats receiving various amounts of cortisone and/or DCA; in thyroidectomized rats given different doses of of thyroxine, the effect of ascorbate administration was evaluated on both resistance to cold and adrenal function.In adrenalectomized rats given large doses of cortisone (2.5 mgm.) and exposed to cold, the administration of either ascorbate (150 mgm.) or DCA (2.5 mgm.) enhances the survival, reduces the extent of thymolysis, and decreases the activation of the thyroid. In adrenalectomized rats receiving no cortisone or DCA or low doses (0.4 and 0.1 mgm.) of these hormones, ascorbate administration (150 mgm.) still retains some of its beneficial effects on resistance to cold (better growth and survival); when low doses of DCA (0.1 mgm.) are given without cortisone, ascorbate administration seems to have a deleterious effect on the growth and survival during exposure to cold, with a greater increase in thyroid activity.In thyroidectomized rats exposed to cold, ascorbate administration (150 mgm.) has no effect in the absence of thyroxine, but increases the efficiency of low doses (3 μgm.) of thyroxine, preventing at the same time some of the typical signs of an alarm reaction: thymolysis and adrenal enlargement.These results are interpreted as showing that the role of the cortical hormones in resistance to cold might be limited to a "conditioning" action and that the beneficial effects of ascorbate administration would be mediated through the thyroid hormones.

Pro-opiocortin: The mutiple adrenal hormone precursor

1984 ◽  
Vol 4 (6) ◽  
pp. 467-482 ◽  
Author(s):  
P. J. Lowry
Keyword(s):  
Pituitary Gland ◽  
Biological Significance ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Adrenal Hormone ◽  
Response To Stress

Corticotropin (ACTH) is biosynthesized in the human pituitary gland as a long polypeptide precursor (pro-opiocortin) of some 240 residues. When ACTH is secreted in response to stress, the peptides derived from the rest or this precursor, pro-γ-melanotropin (γ-MSH) and β-1ipotropin (β-LPH), are also secreted (Fig. 1). This article will describe the search for a biological significance for this phenomenon.

Effect of Ascorbic Acid on Skin Permeability in Adrenalectomized Rats

Nature ◽  
1951 ◽  
Vol 168 (4264) ◽  
pp. 119-120 ◽  
Author(s):  
BENGT H. PERSSON
Keyword(s):  
Ascorbic Acid ◽  
Skin Permeability ◽  
Adrenalectomized Rats

Adrenal cortical function following stepwise removal of the brain in the dog

1959 ◽  
Vol 196 (3) ◽  
pp. 583-588 ◽  
Author(s):  
J. L. Story ◽  
J. C. Melby ◽  
R. H. Egdahl ◽  
L. A. French
Keyword(s):  
Pituitary Gland ◽  
Venous Blood ◽  
Cortical Response ◽  
Cortical Function ◽  
Operative Trauma ◽  
Hypothalamic Lesions ◽  
Response To Stress ◽  
The Brain ◽  
Adrenal Cortical Function

Previous studies indicate that hypothalamic lesions will prevent adrenal cortical response to stress. The present study was undertaken to determine if higher centers of the brain are necessary for adrenal cortical hypersecretion of 17-hydroxycorticosteroids due to operative trauma. Intermittent samples of adrenal venous blood were obtained from dogs by means of adrenal cannulas and 17-hydroxycorticosteroid output was determined. Stepwise removal of the brain was performed, with collections of adrenal venous blood at various levels of anatomic integrity. Removal of the brain down to the hypothalamus resulted in no diminution in the maximal adrenal cortical response following operative trauma as measured by 17-OH-corticosteroid output. After removal of the hypothalamus there is a persistence of adrenal corticoid secretion up to 6 hours after removal of this structure leaving the pituitary gland intact. It is concluded that a) the CNS above the hypothalamus is not essential for adrenal 17-OH-corticosteroid production in response to operative trauma; and b) adrenal cortical secretion persists in response to stress up to 6 hours after removal of the hypothalamus.

ON THE ANTI-INFLAMMATORY ACTION OF AMINOACETONITRILE (AAN)

1957 ◽  
Vol 35 (11) ◽  
pp. 1029-1031 ◽  
Author(s):  
Hans Selye
Keyword(s):  
Inherent Property ◽  
Inflammatory Exudate ◽  
Small Doses ◽  
Anti Inflammatory ◽  
Desoxycorticosterone Acetate ◽  
Inflammatory Action ◽  
Adrenalectomized Rats

Experiments on adrenalectomized rats maintained on small doses of cortisol acetate and desoxycorticosterone acetate indicate that aminoacetonitrile markedly inhibits the production of inflammatory exudate in the "granuloma pouch" test. It is concluded that this antiphlogistic effect is an inherent property of the lathyrogenic aminonitrile and not merely the consequence of an adrenal-mediated stressor action.

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