Sexual dimorphism of renal alpha2-adrenergic receptor regulation in Dahl rats.
Male Dahl salt-sensitive hypertensive (S) rats develop hypertension faster than females. We measured renal alpha2-adrenergic receptor density of inbred Dahl salt-sensitive (SS/JR) and salt-resistant (SR/JR) rats, using [3H]-rauwolscine saturation binding studies. Male and female SS/JR rats were gonadectomized or sham-operated at 6 weeks of age and fed a high salt diet for 4 weeks. Additional intact SS/JR and SR/JR rats of both sexes were fed the high salt diet for a longer period of time (7 weeks instead of 4 weeks). Both blood pressure and renal alpha2-adrenergic receptor density were significantly higher in male than female SS/JR rats on high salt diet for 4 weeks. Gonadectomy did not change blood pressure nor did it change renal alpha2-adrenergic receptor density measured at the 4th week of high salt feeding in either male or female SS/JR rats. When the SS/JR rats were fed high salt diet for a longer period (for 7 weeks), blood pressure of female SS/JR reached the level of males, but the density of renal alpha2-adrenergic receptors was still significantly lower than that of males. Both renal alpha2-adrenergic receptor density and blood pressure were higher in male than female SR/JR. We conclude that higher blood pressure in male Dahl SS/JR and SR/JR rats is associated with higher renal alpha2-adrenergic receptor density compared with their female counterparts.
Gong
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G
Department of Internal Medicine, Creighton University School of Medicine, Omaha, Nebraska 68131, USA.
Dobin
A
A
Johnson
M L
ML
Pettinger
W A
WA
D000317:Adrenergic alpha-Antagonists / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006977:Hypertension, Renal / Q000139:chemically induced / Q000378:metabolism*; D007668:Kidney / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D011869:Radioligand Assay; D051381:Rats; D020303:Rats, Inbred Dahl; D018341:Receptors, Adrenergic, alpha-2 / Q000032:analysis / Q000378:metabolism*; D012727:Sex Characteristics; D017673:Sodium Chloride, Dietary / Q000494:pharmacology; D014316:Tritium; D015016:Yohimbine / Q000378:metabolism / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D018341:Receptors, Adrenergic, alpha-2; D017673:Sodium Chloride, Dietary; D014316:Tritium; D015016:Yohimbine