ACCLIMATIZATION TO COLD: OBSERVATIONS ON THE MECHANISM OF THE REDUCED IMMEDIATE ADRENAL RESPONSE

1959 ◽  
Vol 37 (1) ◽  
pp. 671-677
Author(s):  
Doris Nicholls ◽  
Rosemary Molloy ◽  
Kathleen Stavraky ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Peripheral Nerve ◽  
Cold Stress ◽  
Cold Exposure ◽  
Inorganic Phosphorus ◽  
Phosphorus Metabolism ◽  
Adrenal Tissue ◽  
Adrenal Response

The incorporation of inorganic phosphorus labelled with P32 into the inorganic phosphorus of the adrenal gland was measured in rats acclimatized to cold for 4 weeks. Previously it was reported that the immediate pituitary–adrenal response to brief cold exposure (2 hours at −5 °C), as judged by the increased P32 incorporation is considerably decreased in rats that have been acclimatized. Some observations are now reported on the mechanism of this reduced immediate response.The administration of ACTH, pitressin, or adrenaline caused similar increases in the adrenal phosphorus metabolism in acclimatized and non-acclimatized control rats. Acclimatization could still be demonstrated in rats after the fur had been removed by clipping.From these results it is concluded that the decreased immediate pituitary–adrenal response to an exposure to more severe cold, observed in acclimatized rats, is not the result of an increased fur thickness, nor is it the result of a decreased sensitivity of the adrenal tissue to ACTH, or to a decreased sensitivity of the pituitary or hypothalamus to a given stimulus. It is suggested that the reduction in the immediate pituitary–adrenal response to a more severe cold stress in acclimatized rats might be due to an alteration in the sensitivity of the peripheral nerve receptors, or in the mechanism, nervous or otherwise, whereby the pituitary is stimulated.

ACCLIMATIZATION TO COLD: OBSERVATIONS ON THE MECHANISM OF THE REDUCED IMMEDIATE ADRENAL RESPONSE

1959 ◽  
Vol 37 (5) ◽  
pp. 671-677 ◽  
Author(s):  
Doris Nicholls ◽  
Rosemary Molloy ◽  
Kathleen Stavraky ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Peripheral Nerve ◽  
Cold Stress ◽  
Cold Exposure ◽  
Inorganic Phosphorus ◽  
Phosphorus Metabolism ◽  
Adrenal Tissue ◽  
Adrenal Response

The incorporation of inorganic phosphorus labelled with P32 into the inorganic phosphorus of the adrenal gland was measured in rats acclimatized to cold for 4 weeks. Previously it was reported that the immediate pituitary–adrenal response to brief cold exposure (2 hours at −5 °C), as judged by the increased P32 incorporation is considerably decreased in rats that have been acclimatized. Some observations are now reported on the mechanism of this reduced immediate response.The administration of ACTH, pitressin, or adrenaline caused similar increases in the adrenal phosphorus metabolism in acclimatized and non-acclimatized control rats. Acclimatization could still be demonstrated in rats after the fur had been removed by clipping.From these results it is concluded that the decreased immediate pituitary–adrenal response to an exposure to more severe cold, observed in acclimatized rats, is not the result of an increased fur thickness, nor is it the result of a decreased sensitivity of the adrenal tissue to ACTH, or to a decreased sensitivity of the pituitary or hypothalamus to a given stimulus. It is suggested that the reduction in the immediate pituitary–adrenal response to a more severe cold stress in acclimatized rats might be due to an alteration in the sensitivity of the peripheral nerve receptors, or in the mechanism, nervous or otherwise, whereby the pituitary is stimulated.

EFFECT OF COLD STRESS ON THE PHOSPHORUS METABOLISM OF THE ADRENAL GLAND

1955 ◽  
Vol 33 (1) ◽  
pp. 233-247 ◽  
Author(s):  
Doris Nicholls ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Cold Stress ◽  
Specific Activity ◽  
Phosphorus Metabolism ◽  
P Fractions ◽  
Total Acid ◽  
Radioactive Phosphorus ◽  
Inorganic P ◽  
Relative Specific Activity ◽  
Soluble P

Observations were made on the effects of cold stress (3° ± 1 °C.) on the concentration of phosphorus and the incorporation of inorganic phosphate labelled with radioactive phosphorus (P32) into the following P-containing fractions in the rat: the inorganic P of the plasma, the inorganic P, 20-min. hydrolyzable P, and total acid-soluble P of the adrenal gland. With short periods of cold stress (2, 3, 6, 24 hr.) there was an increase in the relative specific activity of each of the adrenal fractions, greatest for an exposure of 2–3 hr. and least for 24 hr., with no significant change in the specific activity of the inorganic P of the plasma. With longer periods in the cold (2, 4, 8, 16 days), in addition to the usual increase in adrenal weight, there was an increase in the relative specific activity of each of the three acid-soluble P fractions of the adrenal. The increase in specific activity was not due to a decrease in the concentration of P in any of the fractions.Evidence is presented for the view that this change in the phosphorus metabolism of the adrenal can be interpreted in terms of an increase in the rate at which inorganic P32 passes across the cell membrane, i.e. from the extracellular to the cellular fluid. It is suggested that the change after a short (2–3 hr.) exposure to the cold is brought about by the stimulation of the adrenal cortex by endogenous ACTH from the pituitary. The change after longer (several days) exposures may be related to the function of the thyroid gland.

PHOSPHORUS METABOLISM OF THE ADRENAL GLAND OF THE RAT: EFFECT OF EXPOSURE TO A COLD ENVIRONMENT FOR EIGHT DAYS ON THE AMOUNTS AND P32-LABELLING OF PHOSPHOLIPID AND RIBONUCLEIC ACID

1956 ◽  
Vol 34 (1) ◽  
pp. 543-553
Author(s):  
Doris Nicholls ◽  
F. C. Heagy ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Cold Exposure ◽  
Ribonucleic Acid ◽  
Inorganic Phosphate ◽  
Adrenal Glands ◽  
Specific Activity ◽  
Cold Environment ◽  
Phosphorus Metabolism ◽  
Desoxyribonucleic Acid ◽  
Inorganic P

The incorporation of inorganic phosphate labelled with P32 into the lipid P and ribonucleotide P of the adrenal glands of rats exposed to cold (3 ± 1 °C.) for eight days was measured 16 hr. after the P32 injection. In the cold-exposed animals, there was a decrease in the specific activity of both the lipid P and the ribonucleotide P and also a decrease in the specific activity of the lipid P and the ribonucleotide P relative to that of the inorganic P of the adrenal. The cold exposure caused an increase in the amounts of lipid P, ribonucleic acid (RNA), and desoxyribonucleic acid (DNA) per pair of adrenals. There was an increase in the ratio lipid P: DNA-P, but no change in the ratio RNA-P: DNA-P. Calculation showed that the cold exposure caused a decrease in the percentage renewal rate of both lipid P and ribonucleotide P, most of which could be attributed to the increased amounts of lipid P and ribonucleotide P present at the beginning of the isotope experiment. However, when allowance for this was made by calculating the renewal rates of the P of the phospholipid and RNA per pair of adrenals, the values remained slightly less in the cold-exposed animals.

EFFECT OF COLD STRESS ON THE PHOSPHORUS METABOLISM OF THE ADRENAL GLAND

1955 ◽  
Vol 33 (3) ◽  
pp. 233-247 ◽  
Author(s):  
Doris Nicholls ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Cold Stress ◽  
Specific Activity ◽  
Phosphorus Metabolism ◽  
P Fractions ◽  
Total Acid ◽  
Radioactive Phosphorus ◽  
Inorganic P ◽  
Relative Specific Activity ◽  
Soluble P

Observations were made on the effects of cold stress (3° ± 1 °C.) on the concentration of phosphorus and the incorporation of inorganic phosphate labelled with radioactive phosphorus (P32) into the following P-containing fractions in the rat: the inorganic P of the plasma, the inorganic P, 20-min. hydrolyzable P, and total acid-soluble P of the adrenal gland. With short periods of cold stress (2, 3, 6, 24 hr.) there was an increase in the relative specific activity of each of the adrenal fractions, greatest for an exposure of 2–3 hr. and least for 24 hr., with no significant change in the specific activity of the inorganic P of the plasma. With longer periods in the cold (2, 4, 8, 16 days), in addition to the usual increase in adrenal weight, there was an increase in the relative specific activity of each of the three acid-soluble P fractions of the adrenal. The increase in specific activity was not due to a decrease in the concentration of P in any of the fractions.Evidence is presented for the view that this change in the phosphorus metabolism of the adrenal can be interpreted in terms of an increase in the rate at which inorganic P32 passes across the cell membrane, i.e. from the extracellular to the cellular fluid. It is suggested that the change after a short (2–3 hr.) exposure to the cold is brought about by the stimulation of the adrenal cortex by endogenous ACTH from the pituitary. The change after longer (several days) exposures may be related to the function of the thyroid gland.

PHOSPHORUS METABOLISM OF THE ADRENAL GLAND OF THE RAT: EFFECT OF EXPOSURE TO A COLD ENVIRONMENT FOR EIGHT DAYS ON THE AMOUNTS AND P32-LABELLING OF PHOSPHOLIPID AND RIBONUCLEIC ACID

1956 ◽  
Vol 34 (3) ◽  
pp. 543-553 ◽  
Author(s):  
Doris Nicholls ◽  
F. C. Heagy ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Cold Exposure ◽  
Ribonucleic Acid ◽  
Inorganic Phosphate ◽  
Adrenal Glands ◽  
Specific Activity ◽  
Cold Environment ◽  
Phosphorus Metabolism ◽  
Desoxyribonucleic Acid ◽  
Inorganic P

The incorporation of inorganic phosphate labelled with P32 into the lipid P and ribonucleotide P of the adrenal glands of rats exposed to cold (3 ± 1 °C.) for eight days was measured 16 hr. after the P32 injection. In the cold-exposed animals, there was a decrease in the specific activity of both the lipid P and the ribonucleotide P and also a decrease in the specific activity of the lipid P and the ribonucleotide P relative to that of the inorganic P of the adrenal. The cold exposure caused an increase in the amounts of lipid P, ribonucleic acid (RNA), and desoxyribonucleic acid (DNA) per pair of adrenals. There was an increase in the ratio lipid P: DNA-P, but no change in the ratio RNA-P: DNA-P. Calculation showed that the cold exposure caused a decrease in the percentage renewal rate of both lipid P and ribonucleotide P, most of which could be attributed to the increased amounts of lipid P and ribonucleotide P present at the beginning of the isotope experiment. However, when allowance for this was made by calculating the renewal rates of the P of the phospholipid and RNA per pair of adrenals, the values remained slightly less in the cold-exposed animals.

Phosphorus Metabolism of the Adrenal Gland of the Rat

1956 ◽  
Vol 187 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Doris Nicholls ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Inorganic Phosphate ◽  
Room Temperature ◽  
Great Increase ◽  
Phosphorus Metabolism ◽  
Total Acid ◽  
Inorganic P ◽  
Adrenal Response ◽  
Soluble P ◽  
Prior Administration

Observations were made on the incorporation of inorganic phosphate labeled with P32 into the inorganic P, 20-minute hydrolyzable P and total acid-soluble P of the adrenal gland of rats either maintained at room temperature (22 ± 1°C) or conditioned to cold (3 ± 1°C). In confirmation of previous findings, there was an increase in the incorporation of inorganic P32 into the acid-soluble P of the adrenal of the rats maintained in the cold. Exposure to more severe cold (–5°C) for 2 hours, caused a great increase in the incorporation of inorganic P32 into the acid-soluble P of the adrenal of the nonacclimatized rats, compared to a slight, and statistically insignificant, increase in the acclimatized animals. The adrenal response to cold in the nonacclimatized rats was greatly decreased by the prior administration of cortisone.

THE EFFECT OF ADRENALINE, HISTAMINE, AND PITRESSIN ON THE PHOSPHORUS METABOLISM OF THE ADRENAL GLAND

1957 ◽  
Vol 35 (6) ◽  
pp. 401-406
Author(s):  
Doris Nicholls ◽  
Carolyn Graham
Keyword(s):  
Ascorbic Acid ◽  
Adrenal Gland ◽  
Specific Activity ◽  
Previous Treatment ◽  
Inorganic Phosphorus ◽  
Phosphorus Metabolism ◽  
Inorganic P ◽  
Relative Specific Activity ◽  
Hypophysectomized Rats ◽  
Valid Index

The relative specific activity of the inorganic phosphorus of the adrenal gland of rats 2 hours after an intraperitoneal injection of inorganic P32 was increased by the administration of adrenaline, histamine, or commercial pitressin. These substances are all known to cause a depletion of the adrenal ascorbic acid. The effect on the adrenal phosphorus metabolism, like the effect on the adrenal ascorbic acid, was absent or greatly reduced in hypophysectomized rats and in rats previously treated with cortisone.In hypophysectomized rats the administration of exogenous ACTH caused an increase in the relative specific activity of the adrenal inorganic P and, again like the adrenal ascorbic acid depletion, this increase was not abolished by previous treatment with cortisone.These results, together with other observations on adrenal phosphorus metabolism previously reported for rats exposed to a cold environment, strongly suggest that the incorporation of inorganic P32 into the adrenal gland is controlled by the same factors that control the depletion of adrenal ascorbic acid. It is, therefore, concluded that the incorporation of inorganic P32 into the adrenal gland is a valid index of the activity of the adrenal cortex.

THE EFFECT OF ADRENALINE, HISTAMINE, AND PITRESSIN ON THE PHOSPHORUS METABOLISM OF THE ADRENAL GLAND

1957 ◽  
Vol 35 (1) ◽  
pp. 401-406
Author(s):  
Doris Nicholls ◽  
Carolyn Graham
Keyword(s):  
Ascorbic Acid ◽  
Adrenal Gland ◽  
Specific Activity ◽  
Previous Treatment ◽  
Inorganic Phosphorus ◽  
Phosphorus Metabolism ◽  
Inorganic P ◽  
Relative Specific Activity ◽  
Hypophysectomized Rats ◽  
Valid Index

The relative specific activity of the inorganic phosphorus of the adrenal gland of rats 2 hours after an intraperitoneal injection of inorganic P32 was increased by the administration of adrenaline, histamine, or commercial pitressin. These substances are all known to cause a depletion of the adrenal ascorbic acid. The effect on the adrenal phosphorus metabolism, like the effect on the adrenal ascorbic acid, was absent or greatly reduced in hypophysectomized rats and in rats previously treated with cortisone.In hypophysectomized rats the administration of exogenous ACTH caused an increase in the relative specific activity of the adrenal inorganic P and, again like the adrenal ascorbic acid depletion, this increase was not abolished by previous treatment with cortisone.These results, together with other observations on adrenal phosphorus metabolism previously reported for rats exposed to a cold environment, strongly suggest that the incorporation of inorganic P32 into the adrenal gland is controlled by the same factors that control the depletion of adrenal ascorbic acid. It is, therefore, concluded that the incorporation of inorganic P32 into the adrenal gland is a valid index of the activity of the adrenal cortex.

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