Raised prorenin and renin concentrations in pre-eclamptic placentae when measured after acid activation.

AIM: The aim of the study was to ascertain if there was any difference in the levels of prorenin and active renin between pre-eclamptic and normotensive feto-placental tissues. METHODS: Supernatants of homogenates from fresh, vaginally delivered placentae from 15 normotensive and 15 pre-eclamptic women were measured for renin concentration (RC), prorenin concentration and renin activity (RA). RA and RC were measured in the absence and presence of nephrectomised sheep plasma, respectively. Prorenin was estimated as the difference between renin concentration in the sample before and after acid activation. All concentrations are expressed as rate of angiotensin generation (ng/ml/h). Angiotensin I was measured by radioimmunoassay. Statistical analysis was performed using Student's 't' test for unpaired samples. All results are presented as mean+/-SEM. RESULTS: The concentrations of renin and prorenin were highest in the chorion laeve when compared to amnion and placenta (p < 0.01) in both the groups. Furthermore, the concentrations of renin and prorenin were significantly higher in all the tissues from women with pre-eclampsia (p < 0.01). CONCLUSION: Renin and prorenin levels are raised in the placental tissues from women with pre-eclampsia. With recent evidence suggesting that both prorenin and renin may have cellular effects independent of angiotensin II generation, there is a need for further study into its role in placentation.

Relationship between Type A and B personality and debrisoquine hydroxylation capacity.

AIM: A person with Type A personality is an 'aggressor' compared with the rarely harried Type B. Although debrisoquine hydroxylase (CYP2D6) capacity has been associated with personality, no study has specifically investigated its association with personality Type A and B. Therefore the aim of this research was to study the impact of CYP2D6 on Type A and B personality. METHODS: Type A and B personality questionnaires were administered to 48 healthy patients undergoing elective orthopaedic surgery. After obtaining informed consent, patients were genotyped for the various CYP2D6 alleles by allele-specific polymerase chain reaction. Based on the genotypes, patients were grouped as extensive metabolizer (EM)1 (normal) (CYP2D6*1/*1), EM2 (intermediate) (CYP2D6*1/*4, CYP2D6*1/*5, CYP2D6*1/*9 and CYP2D6*1/*10) and EM3 (slow) (CYP2D6*4/*10, CYP2D6*5/*10, CYP2D6*10/*10 and CYP2D6*10/*17). Chi(2) was used to determine the relationship between the groups and personality types. RESULTS: The percentages of patients who were of the EM1, EM2 and EM3 groups were 20.8%, 52.1% and 27.1%, respectively. There was a significant difference (P = 0.032) between the three groups in terms of personality type, in which EM1 showed a tendency to be of personality Type A while EM2 and EM3 tended to be of personality Type B. CONCLUSION: The study suggests that there is a relationship between CYP2D6 activity and Type A and B personality.

Endothelin-l in feto-placental tissues from normotensive pregnant women and women with pre-eclampsia.

AIMS: The pathogenesis of pre-eclampsia is still unclear. Placental hypoperfusion, which precedes the maternal manifestations of pre-eclampsia, could be due to some vasoconstrictor factor/s like endothelin-1. The aim of the study therefore was to estimate the levels of endothelin-1 in feto-placental tissue homogenates from normotensive pregnant women and women with pre-eclampsia. METHOD AND MATERIAL: Fresh, vaginally delivered placentae from ten normotensive pregnant women and nine women with pre-eclampsia were carefully dissected and 4 gm each of amnion, chorion laeve, placental plate chorion, fetal placenta (fetal surface of the placenta) and maternal placenta (surface of the placenta attached to the uterine wall) were obtained. These tissues were then thoroughly washed in a 0.5 M phosphate buffer, pH 7.5, at room temperature and then individually homogenized for one minute in 4 ml of the same buffer. After centrifugation the supernatant was removed. The pellet was re-suspended in buffer, re-homogenized and then centrifuged. The supernatant was removed and the procedure was repeated once again and the three supernatants of each tissue were pooled. Endothelin-1 was estimated by RIA. All results are presented as mean+/-SEM. Statistical analysis was performed using students 't' test for unpaired samples and a 'p' value of <0.05 was considered significant. RESULTS: In tissues from normotensive pregnant women, no significant differences were evident in endothelin-1 concentrations in the chorion laeve, fetal placenta and maternal placenta but were significantly higher than those in the amnion and placental plate chorion (p<0.01). In tissues from pre-eclamptic women, no significant differences were evident between endothelin-1 concentrations in the chorion laeve, placental plate chorion and fetal placenta. Mean endothelin-1 concentration in the amnion and maternal placenta were significantly lower than those in chorion laeve, placental plate chorion and fetal placenta (p<0.01). Endothelin-1 concentrations were significantly higher in the amnion, chorion laeve, placental plate chorion and fetal placenta from women with pre-eclampsia when compared to tissues from normotensive pregnant women (p<0.01). CONCLUSIONS: Endothelin-1 levels were significantly higher in the placental tissues from women with pre-eclampsia. Endothelin-1, being a powerful vasoconstrictor, could cause significant vasoconstriction in the placental vasculature, and alterations in endothelin-1 levels in placental vasculature may therefore have a role in the pathogenesis of pre-eclampsia.

The in vitro effects of griffonin and ouabain on erythrocyte sodium content obtained from normal subjects and sickle cell patients.

The in vitro effects of griffonin and ouabain on erythrocyte sodium content have been investigated in 6 normal subjects and 6 sickle cell patients. Intracellular sodium contents of normal or sickle cells incubated for 8 h in tris buffer, griffonin/tris buffer, or ouabain/tris buffer were determined. Incubation of normal cells in tris buffer or 0.5 mmol/l griffonin had little effect on the cell sodium content. However, 1.0 mmol/l griffonin/tris buffer raised the cell sodium level (P less than 0.05) over the incubation period. Ouabain/tris buffer (0.5 mmol/l or 1.0 mmol/l) also raised the sodium content (P less than 0.05 to P less than 0.001). Incubation of sickle cells in tris buffer raised the cell sodium (P less than 0.05) as did 0.5 mmol/l or 1.0 mmol/l griffonin (P less than 0.05 to P less than 0.001). Ouabain/tris buffer (0.5 mmol/l or 1.0 mmol/l) raised the intra-erythrocyte sodium level (P less than 0.01 to P less than 0.001). These findings suggest that ouabain and griffonin both have similar actions on intra-erythrocyte sodium content although ouabain was more potent. It is suggested therefore that griffonin could be a useful anti-sickling drug for sickle cell disease crisis.

Total body water, total exchangeable sodium and related variables in the Ghanaian.

1. Standard radioisotope dilution techniques employing [3H]water and [22Na]sodium chloride have been used to determine the total body water and total exchangeable sodium of 20 male and 10 female normal Ghanaians (Africans) aged 19--25 years. 2. Lean body mass and total body fat are calculated as a percentage of body weight; the total exchangeable sodium values have been expressed in relation to lean body mass. 3. Comparison of the data for Ghanaian subjects with published figures for Caucasian subjects of similar age shows that the Ghanaian men have much less total body fat and the women a little less total body fat than their Caucasian counterparts. 4. Total exchangeable sodium expressed in terms of lean body mass shows close agreement in both men and women.