No clear association was apparent between the use of antihypertensive drugs and prostate cancer. However, specific focus on users of captopril showed a lower risk of subsequent prostate cancer. Further research is needed to explore this association.

A lower rate of biochemical recurrence was observed in men subjected to radical prostatectomy treated with captopril postoperatively than in those not receiving captopril. These results were based on only 32 observations; a larger study may show no evidence of an association.

No abstract

Erythrocyte fluidity and other haemorheological variables were studied in 22 patients with essential hypertension and compared with age- and sex-matched healthy controls. Hypertensive patients displayed a significantly lower erythrocyte fluidity (P less than 0.001). Similarly, significantly elevated values for haematocrit, plasma and whole blood viscosity, as well as aggregation tendency were observed compared to controls. Although differing in these respects from controls, there were no obvious relationships between these rheological variables and either systolic or diastolic blood pressure. The significantly lower erythrocyte fluidity and other changes in haemorheological variables of red blood cells found in hypertensive patients may be explained by an enlarged metabolic pool of free calcium ions in these red blood cells. It is suggested that the molecular mechanisms underlying the evolution of essential hypertension are multifactorial rather than being based on a single molecular derangement. Primary events resulting in altered physicochemical properties of the red blood cells may work in concert in the development of essential hypertension, in addition to the increased availability of calcium ions and their potential role in smooth muscle contraction.

Seminal plasma from 22 men attending an infertility clinic was subjected to preparative ultracentrifu-gation for 2 h at 105,000 g. The pelleted material as well as the supernatant thus obtained were investigated with regard to prostasome membrane-linked enzyme activities in relation to other semen parameters. The mean activity of Zn²⁺-dependent adenosine triphosphatase in the sedimented prostasome fraction was 1.45 ± 1.02 µmol (range 0.29–4.79) orthophosphate released per milligram protein and 20 min, while the corresponding figures for the supernatant were 0.56 ± 0.30 (range 0.12–1.29). Hence, 72% of the specific activity was sedimented, and 28% remained in the supernatant. The same pattern was recognized with regard to the other two enzymes investigated, although they displayed individual characteristics with regard to distribution after ultracentrifugation. The pelleted prostasome-linked mean aminopeptidase activity was 0.39 U/mg protein (81.9%), with only 0.087 U (18.1%) remaining in the supernatant. The corresponding figures for Γ-glutamyltransferase were 7.89 (60.4%) and 5.17 (39.6%) µkat/g protein, respectively. The different enzyme activities in the prostasome fraction and supernatant, respectively, were interrelated to each other and correlated significantly with r values between 0.73 and 0.93 (p < 0.001). It was concluded that a minor fraction of prostasomes remained in the supernatant after ultracentrifugation. A relationship existed between prostasomes and semen volume revealing a rather consistent pattern in that small volumes favoured the presence of comparatively more prostasomes in the supernatant and less prostasomes in the pelleted fraction than large volumes. In addition, the sperm concentration seemed to be another determinant of the distribution of prostasomes in seminal plasma on subsequent ultracentrifugation.