Thyroid function in the desert tortoise, Gopherus agassizii /
(T4) exhibited distinct cycles in both sexes, being lowest
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1994.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Summary: | (T4) exhibited distinct cycles in both sexes, being lowest Additionally, testosterone increased dramatically in this aggressive behavior associated with increased testosterone. and increased mating and combat in the late summer. Thus, an assimilation. The second peak of T4 in males may be due to contributes to increased T4, tortoises were fasted for two detectable (less than 0.01 ng/ml). Circulating amounts of T3 during hibernation and rising toward the time of emergence. feeding, mating, and locomotor activity in the early spring Females exhibited only one peak in T4, during the early function, adult, subadult, and juvenile male tortoises were group. Thus, elevated T4 in desert tortoises is associated have distinct activity patterns that include increased in late summer. The desert tortoise has been reported to increase in T4 may be a result of increased food intake or increased feeding elevates T4, possibly to support nutrient increasing testosterone not seen in the females or male maintained at the Desert Tortoise Conservation Center in Las may reflect a low rate of T4 to T3 conversion. Thyroxine metabolic rate after emergence. To determine if food intake peaked in July only in reproductively active adults. period of two years in desert tortoises, Gopherus agassizii, sampled during the months of the second peak in male T4. T4 spring. In males, T4 levels peaked in early spring and again supporting the proposal that this hormone serves to support terrestrial reptile, thyroid hormones were measured over a these energy-demanding activities. To characterize seasonal changes in thyroid function in a To evaluate the effects of reproductive condition on thyroid Vegas, NV. In all samples, triiodothyronine (T3) was non weeks. Upon refeeding, T4 levels increased, indicating that with periods of increased feeding and reproductive activity, |
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| Item Description: | "Major subject: Zoology". Vita. |
| Physical Description: | viii, 50 leaves : illustrations ; 28 cm. Also available online. |
| Bibliography: | Includes bibliographical references. |