EARLY SEPARATION AND THE DEVELOPMENT OF IMPAIRED THERMOREGULATION IN RATS: A RISK FACTOR IN GASTRIC ULCER SUSCEPTIBILITY (BROWN ADIPOSE TISSUE, METABOLISM).
Item
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Title
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EARLY SEPARATION AND THE DEVELOPMENT OF IMPAIRED THERMOREGULATION IN RATS: A RISK FACTOR IN GASTRIC ULCER SUSCEPTIBILITY (BROWN ADIPOSE TISSUE, METABOLISM).
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Identifier
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AAI8409392
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identifier
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8409392
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Creator
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GREENBERG, DANIELLE.
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Contributor
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Gerald Turkewitz
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Date
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1984
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Physiological
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Abstract
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Previous work showed that rats prematurely separated from dams at 15 days of age subsequently have heightened vulnerability to restraint induced gastric erosions (RGEs). This vulnerability was highly correlated with a fall in body temperature during restraint at normal room temperatures. The present work examined the nature of the thermoregulatory disturbances of prematurely weaned rats.;As available fat is important in heat production, I investigated differences in fat deposition of early and normally weaned rats. Early weaned rats had significantly less white and brown adipose tissue than normally weaned rats. Early weaned rats also had relatively greater fat depletion during conditions of food deprivation and restraint. A high correlation was found between hypothermia or RGE susceptibility and low body fat content.;The competence of 30 day old rat's behavioral thermoregulation was assessed. Rats were tested on a thermal runway where free choice of ambient temperature was available, and in situations of inescapable heat and cold. Robust differences in temperature selection behaviors of early and normally weaned rats were not found. However, rats of both weaning conditions evidenced the ability to detect and avoid temperature extremes. In inescapable cold early weaned rats responded appropriately, showing significantly greater incidences of heat producing behaviors than normally weaned rats. However, early weaned rats became relatively hypothermic during 20 minute test sessions. Thus 30 day old early weaned rats mobilize behavioral mechanisms for heat production but these behaviors are ineffective in preventing hypothermia.;Oxygen consumption measurement was used to assess physioloical thermoregulatory mechanisms of early and normally weaned rats. During food deprivation or food deprivation and restraint, early weaned rats became hypothermic and used significantly less oxygen than normally weaned rats. When food was available early weaned rats used as much oxygen as normally weaned rats. Food deprived early weaned animals did not increase oxygen consumption in response to exogenous norepinepherine.;I concluded that early weaned rats are more vulnerable than normally weaned rats to hypothermia during food deprivation and restraint because heat production is diminished and fuel stores are more depleted.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Psychology
