The effects of oestradiol administration on blood pressure and erythrocyte Na+ influx in oophorectomized rats.
The effects of oestrogen on blood pressure and erythrocyte Na+ influx were measured in oophorectomized rats treated with oestradiol benzoate (100ug/kg/week i.m.) or vehicle for eight weeks. A significant increase in mean blood pressure was observed in the oestradiol-treated compared to the vehicle-treated group, together with a significant increase in red cell [Na+]. Oestradiol administration produced no significant changes in total Na+ influx, cotransport, countertransport or Na+ diffusion and did not alter plasma [Na+], red cell [K+], mean corpuscular haemoglobin concentration (MCHC) or blood volume per 100g body weight. However, significant decreases in body weight, haematocrit and plasma [K+] were observed in the oestradiol-treated group. These results support previous observations that oestradiol increases blood pressure and suggest that chronic administration of oestrogen increases red cell [Na+], probably by a mechanism other than alteration in erythrocyte passive Na+ transport.
Flemming
C L
CL
Department of Clinical Pharmacology, Royal North Shore Hospital, St Leonards, NSW, Australia.
Marwood
J F
JF
Stokes
G S
GS
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D010052:Ovariectomy; D011188:Potassium / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000097:blood*
D004958:Estradiol; D012964:Sodium; D011188:Potassium