Plasma aldosterone concentration of cats

Aldosterone concentrations in the plasma of specific-pathogen-free, domestic, short-hair cats given sodium replete diets were measured by a radio-immunoassay. Plasma samples assayed were taken from male and female cats of 8, 12, 17, 20, 26, 29, 40 and > 52 weeks of age, from adult non-pregnant queens, and from queens in the ninth weeks of pregnancy and in the second and fifth week of lactation. Plasma aldosterone concentration was also measured in samples taken four times over a 24 h period (06:00-06:30, 11:00-11:30, 17:00-17:30 and 23:00-23:30) in a group of seven adult male cats. neither age nor sex had a significant effect on the plasma aldosterone concentration. Also, queens had similar aldosterone concentrations in plasma whether they were non-pregnant, pregnant, or lactating. No circadian rhythm was observed in plasma aldosterone concentrations in adult male cats. The plasma aldosterone concentrations of 148 cats (87 males and 61 females, ranging in ages from 8 to > 52 weeks) had a positive skew distribution with a median of 161 pmol l-1. The upper value for plasma aldosterone concentration in healthy domestic cats as defined by the 95 percentile was 700 pmol l-1.