The effects of long‐term exposure to cold upon adrenal weight and ascorbic acid content in wild and domesticated norway rats

Woods, J. W.

doi:10.1113/jphysiol.1957.sp005717

Cited by 13 publications

(3 citation statements)

References 8 publications

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“…On purely teleological grounds this suggestion appears to warrant consideration. The results reported here and others from long-term stress experiments (Woods, 1957) raise the question as to whether or not exposure to stress actually does result in increased adrenal cortical secretion in wild animals.…”

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confidence: 55%

“…So far, only a few attempts have been made to correlate this comparatively large amount of adrenal cortical tissue with the function of the organ (Rogers & Richter, 1948;Nichols, 1948; Richter, 1950;Covian, 1949). It has been suggested (Richter, 1950; Covian, 1949) (Woods, 1957) raise the question as to whether or not exposure to stress actually does result in increased adrenal cortical secretion in wild animals.…”

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confidence: 99%

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The effects of acute stress and of ACTH upon ascorbic acid and lipid content of the adrenal glands of wild rats

Woods¹

1957

The Journal of Physiology

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confidence: 55%

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confidence: 99%

The effects of acute stress and of ACTH upon ascorbic acid and lipid content of the adrenal glands of wild rats

Woods¹

1957

The Journal of Physiology

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“…Studies of the effect of chronic cold or isolation on rats have generally indicated a transient activation of the pituitary-adrenal system, as measured by reduced body growth, increased adrenal size, increased plasma corticosterone levels, and other correlates of adrenal activation (5,(9)(10)(11)(12). Furthermore, chronic exposure to cold is a situation that provides little possible behavioral release mechanism.…”

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confidence: 97%

Pituitary-Adrenal Function in Rats Chronically Exposed to Cold

et al. 1982

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Exposure to cold for 2 weeks was used to assess the effects of a sustained stimulus on pituitary-adrenal function in male rats. The diurnal peak in plasma and adrenal corticosterone was advanced by 4 h during the first 24 h of exposure to cold but returned to its usual time (2000 h) by the next day. Plasma ACTH and corticosterone levels were generally greater at all times during the 24-h cycle in animals exposed to cold for up to 2 weeks, with the greatest increase occurring consistently at the time of peak. When rats exposed to cold for 1 week were returned to a normal 24 C environment, plasma corticosterone tended to increase. Plasma ACTH and plasma and adrenal corticosterone responses to a superimposed acute provocative stimulus (ip saline injection) were faster, greater, and more sustained in rats exposed to cold for 3 or 7 days. Similarly, the compensatory adrenal hypertrophy response to unilateral adrenalectomy was greater in cold-exposed rats. Such animals were also more resistant to pituitary-adrenal suppression by prednisolone. In contrast, there was no change in the sensitivity of the adrenal to exogenous ACTH. The results suggest that chronic exposure to cold causes a sustained activation of central mechanisms that regulate pituitary ACTH secretion as well as extra-pituitary mechanisms that regulate adrenal size; it reduces the effectiveness of negative feedback mechanisms, but does not alter those involved in the regulation of adrenal rhythmicity or adrenal sensitivity to ACTH.

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Histologic and physiologic comparisons of the thyroid glands of the wild and domesticated norway rat

Mosier¹,

Richter²

1967

Anat. Rec.

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A comparison of the histological pattern of the thyroid glands of 138 wild and 157 domesticated Norway rats showed that the domesticated rat has smaller epithelial cells, greater uniformity in the size of follicles, larger follicular lamina, and fewer vacuoles in the iiitrafollicular colloid. These differences are not present at birth but develop gradually with age. Hypophysectomy causes a loss of these differences and results in an identical histologic pattern of atrophy in the two strains of rats. There is greater uniformity of thyroid uptake and labelling of the components of thyroglobulin in the domesticated rat, but the average percent uptake of IL3' in the thyroid glands of hoth strains is the same.These differences may bc accountable partly on the basis of different reactions to the environment conditioned by diffcrent temperaments in the two strains, by actual differences in the environrncnt, and by genetic differences.Striking physiological and temperamental differences between the wild and domesticated Norway rat have been described by Richter ('49). The present paper is concerned with comparisons of the thyroid glands of wild and domesticated Norway rats. Although previous workers found no difference in the weight of the gland (Hatai, '14; Donaldson, '24; King and Donaldson, '29), we have observed a tendency for heavier gland weight in the wild Norway rat and other differences in the gross appearance of the glands of many hundreds of adult live and dead rats. The thyroid glands of wild rats are long, slender, and a brownish hue; those of domesticated rats are short, round, and pink or red in color (Richter and Dieke, unpublished), A further study now has been made to determine whether there are any differences in thyroid histology or function between the two strains. METHODSOne hundred thirty-eight wild Norway rats and 157 domesticated rats were used for the study. The wild rats were trapped or shot on farms in Maryland or in the municipal dump, alleys and backyards in Baltimore. Captive wild rats were fed Purina Fox-chow. The domesticated rats were all from the Richter colony which has been in continuous existence since 1923, having been started with albino rats from ANAT. REC., 158: 263-274. The Wistar Institute. A few non-albinos from the stock of Dr. E. V. McCollum were added about 35 years ago. During a fouryear period (12th-16th year) of the colony's existence some rats, especially females, were selected for running activity. There has been no other planned selection. From the time of weaning the domesticated rats were fed a standard diet and tap water ad lib., with a weekly supplement of lettuce. They were kept in a wellventilated room at an average temperature of 25°C and all were handled at least once a week. The wild rats used for thyroid weight measurement were killed and dissected as soon as they were brought into the laboratory. No control of the quality or quantity of food eaten by the rats in the wild environment was possible. This is thus a n uncertain factor except in the ca...

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The effects of long‐term exposure to cold upon adrenal weight and ascorbic acid content in wild and domesticated norway rats

Cited by 13 publications

References 8 publications

The effects of acute stress and of ACTH upon ascorbic acid and lipid content of the adrenal glands of wild rats

The effects of acute stress and of ACTH upon ascorbic acid and lipid content of the adrenal glands of wild rats

Pituitary-Adrenal Function in Rats Chronically Exposed to Cold

Histologic and physiologic comparisons of the thyroid glands of the wild and domesticated norway rat

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