GENDER DIFFERENCES IN ANALGESIC PROCESSES IN RATS: INFLUENCE OF GONADAL AND HORMONAL FACTORS.
Item
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Title
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GENDER DIFFERENCES IN ANALGESIC PROCESSES IN RATS: INFLUENCE OF GONADAL AND HORMONAL FACTORS.
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Identifier
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AAI8801752
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identifier
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8801752
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Creator
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ROMERO, MARIA-TERESA.
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Contributor
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Richard J. Bodnar
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Date
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1987
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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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Gender specific differences are observed both in the perception of noxious stimuli and morphine analgesia in rats. Consequently, the purpose of the present dissertation was to determine whether gender and gonadal steroids play a modulatory role in analgesia processes. Pain thresholds were measured with the tail-flick and jump tests. The first experiment evaluated gender differences in continuous cold water swim (CCWS), intermittent cold water swim (ICWS), 2-Deoxy-D-Glucose (2DG) and systemic morphine analgesia. In order to control for body weight differences, adult age-matched male and female rats and a third group of younger male rats, weight-matched to the female group were used as subjects. Female rats displayed significantly less analgesia than young and adult males following CCWS, ICWS and morphine. Gender differences failed to appear following central morphine administration, suggesting a peripheral mechanism for the gender differences observed in systemic morphine analgesia. Estrous cycle had no effect on the magnitude of CCWS analgesia. The second study evaluated the role of gonadal status of the organism in the observed gender differences. Castration significantly reduced CCWS and ICWS analgesia to levels observed in the intact female. Ovariectomy reduced CCWS and ICWS analgesic magnitude further. This reduction could not be accounted for by changes in CCWS and ICWS hypothermia, activity during the swim or post-operative weight changes. Naloxone significantly reduced opioid-mediated ICWS analgesia in males, but not in females. Nonopioid-mediated CCWS analgesia was not affected by naloxone pretreatment. In the third experiment testosterone proprionate (TP) and estradiol benzoate (EB) were administered to intact and gonadectomized male and female rats. The magnitude of CCWS and ICWS analgesia was reinstated by TP treatment in castrated males and ovariectomized females. TP potentiated CCWS analgesia in intact males. EB attenuated CCWS analgesia in intact females and reinstated ICW analgesia in ovariectomized females. These results suggest that TP, but not EB plays an important role in the gonadal modulation of both opioid-mediated and nonopioid-mediated forms of swim analgesia, but that supplements of neither steroids to intact rats consistently alters these analgesic responses.
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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
