Abstract
The effect of 17 beta-oestradiol pretreatment and the natural oestrous cycle on responses of rat cardiac and vascular alpha-adrenoceptors was investigated. It was found that treatment with the oestrogen had no effect on cardiac adrenoceptor sensitivity, while pretreatment with the hormone caused a significant increase in vascular alpha 2-, but not vascular alpha 1-adrenoceptor responsiveness. Pressor responses of pithed rats to selective alpha 1- or alpha 2-adrenoceptor agonists did not alter, however, during the natural oestrous cycle. These findings suggest that changes in oestrogen levels are capable of altering alpha-adrenoceptor-mediated vascular responses but that the relatively small changes in oestrogen which may occur throughout the natural oestrous cycle do not appear to alter the responses of these vascular alpha-adrenoceptors.
Original language | English |
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Pages (from-to) | 656-60 |
Number of pages | 5 |
Journal | Journal of Pharmacy and Pharmacology |
Volume | 47 |
Issue number | 8 |
DOIs | |
Publication status | Published - 31 Aug 1995 |
Keywords
- Adrenergic alpha-Agonists/pharmacology
- Animals
- Blood Pressure/drug effects
- Decerebrate State
- Dose-Response Relationship, Drug
- Estradiol/pharmacology
- Estrus/physiology
- Female
- Heart Atria/drug effects
- Heart Rate/drug effects
- In Vitro Techniques
- Neuromuscular Junction/drug effects
- Ovariectomy
- Papillary Muscles/drug effects
- Rats
- Rats, Wistar
- Receptors, Adrenergic, alpha/drug effects