Tolerance of estrogen-treated rats to acute cold exposure
| Autor: | Melvin J. Fregly, Dennis L. Kelleher, D. J. Black |
|---|---|
| Rok vydání: | 1979 |
| Předmět: |
medicine.medical_specialty
Colon Physiology medicine.drug_class Untreated group Cold exposure chemistry.chemical_element Ethinyl Estradiol Oxygen Body Temperature Oxygen Consumption Animal science Physiology (medical) medicine Animals Drug Interactions Cold stress Chemistry Body Weight Heat losses Norethynodrel Rats Surgery Cold Temperature Estrogen Acute exposure Female Body Temperature Regulation |
| Zdroj: | Journal of Applied Physiology. 47:59-66 |
| ISSN: | 1522-1601 8750-7587 |
| Popis: | Female rats treated chronically with ethynylestradiol (36 micrograms/kg per day) alone, and in combination with the progestational agent, norethynodrel (253 micrograms/kg per day), cooled significantly faster than controls when lightly restrained and exposed to air at 5 degrees C. Rate of cooling of rats given only norethynodrel was similar to that of the control group. In other studies, rate of oxygen consumption was determined for all groups during acute exposure to cold (14 degrees C). All estrogen-treated groups achieved the same maximal rate of oxygen consumption as control and norethynodrel-treated groups during cold exposure, but cooled significantly faster. Two groups of female rats were treated chronically with ethynylestradiol at two separate doses (36 and 61 micrograms/kg per day). An untreated group served as controls. Rate of oxygen consumption of all animals were measured during restraint and exposure to cold (18 degrees C). The estrogen-treated groups again achieved the same maximal rate of oxygen consumption as the control group, but also cooled significantly faster despite the fact that the cold stress was less severe than in the previous experiment. That estrogen-treated rats cooled faster than controls in both studies despite achieving a maximal rate of heat production which did not differ from controls suggests that reduced cold tolerance of estrogen-treated rats may be related to increased heat loss. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|