ABSTRACT
A low-salt diet is known to decrease and salt excess to increase blood pressure in humans and rodents. Sex steroids seem to play a role in salt dependent hypertension. However, little is known about sex differences in mineralocorticoid receptor blockade between male and female rats. The objective of the work was at first to investigate the effects of a low-salt vs. a high-salt diet on blood pressure without the influence of gonadal steroids in male and female rats. Second, to determine the sex-specific effects of mineralocorticoid receptor blockade by spironolactone in high-salt and low-salt fed gonadectomized male and female animals. Normotensive male and female Wistar rats were gonadectomized and put on a low (NaCl<0.03%) or high (NaCl=4%) salt diet. On each diet animals received spironolactone or placebo. Blood pressure was measured by tail-cuff-method; 24-h urine samples were collected in metabolic cages and blood was collected for hormonal measurements. High-salt diet significantly increased systolic blood pressure in both sexes. This effect could be blocked effectively by spironolactone only in male rats. Spironolactone treatment significantly increased aldosterone levels in males and females independent of the sodium content of the diet. High sodium diet significantly increased relative kidney weight, which was not altered by spironolactone treatment. Independently of gonadal steroids a high-salt diet increased blood pressure in gonadectomized male and female rats. Spironolactone lowered blood pressure only in male not in female rats on a high-salt diet clearly indicating sex-specific effects of the mineralo-corticoid antagonist spironolactone.
Subject(s)
Blood Pressure/drug effects , Gonads/surgery , Hypertension/drug therapy , Hypertension/physiopathology , Mineralocorticoid Receptor Antagonists/administration & dosage , Spironolactone/administration & dosage , Aldosterone/metabolism , Animals , Female , Gonads/metabolism , Humans , Hypertension/genetics , Hypertension/metabolism , Male , Orchiectomy , Ovariectomy , Rats , Rats, Wistar , Receptors, Mineralocorticoid/genetics , Receptors, Mineralocorticoid/metabolism , Sex FactorsABSTRACT
BACKGROUND: Much interest has been drawn to the investigation of the hypothalamic-pituitary-thyroid (HPT)-axis in patients suffering from depression or panic disorder. However, there is no data concerning agoraphobia. METHODS: Patients with panic disorder, agoraphobia, major depression were compared to normal controls (total n=88) in respect to HPT axis, obtaining basal TSH and administering a TRH test. RESULTS: Normal controls and agoraphobics showed significantly higher Delta(max) TSH than depressives and panic patients. There were no differences between agoraphobics and normal controls. CONCLUSIONS: Agoraphobia, unlike depression or panic disorder, seems to be less biologically determined in respect to the HPT-axis.
