[Viscocanalostomy: preliminary clinical results]. / Viscocanalostomie: résultats cliniques à court terme.

PURPOSE: Filtration surgery has shifted in the past 20 years to a nonperforating surgery to reduce complications. The purpose of this study was to assess the short-term clinical results and complications of viscocanalostomy. PATIENT AND METHODS: In a prospective and nonrandomized study, 107 consecutive eyes of 67 patients who underwent viscocanalostomy were analyzed. The surgeon conducted postoperative care. The minimal follow-up was 1 year, with a mean follow-up of 13.1 months (range, 12-18 months). The criteria for success were defined as intraocular pressure (IOP) less than 21 mmHg without treatment. RESULTS: The mean preoperative intraocular pressure was 28.3 mmHg while the mean postoperative intraocular pressure was 5.4 mmHg on the first day and 10.2 mmHg at 13 months. The rate of patients who had intraocular pressure below 21 mmHg with or without treatment was 98% at 13 months. The complete success rate without treatment was 80% at 13 months. Seven cases of ocular hypotony lasting more than 1 month were noted. CONCLUSION: Viscocanalostomy is a promising procedure because in the short term it provides good tonometric results in glaucomatous patients without the complications of trabeculectomy. However, it remains a technique with a learning curve.

Antihypertensive activity of the aqueous extract of Retama raetam Forssk. leaves in spontaneously hypertensive rats.

The antihypertensive and diuretic effects of the aqueous extract of Retama raetam Forssk. (RR) leaves were studied in both normotensive (WKY) and spontaneously hypertensive rats (SHR). In SHR rats, daily oral administration of RR (20 mg/kg) for three weeks exhibited a significant reduction in blood pressure. The systolic blood pressure decreased significantly from the seventh day (P < 0.01) and persisted through the end of treatment (P < 0.001) in SHR rats. The RR significantly enhanced the diuresis in WKY rats (P < 0.001). Furthermore, oral administration of RR at a dose of 20 mg/kg produced a significant increase on urinary excretion of sodium (P < 0.05), potassium (P < 0.01) and chlorides (P < 0.01) in SHR rats. In WKY rats, RR treatment induced a significant increase on urinary potassium elimination (P < 0.05) without affecting sodium and chloride excretion. Irbesartan (Avapro) 20 mg/kg (body weight), an angiotensin II receptor antagonist, was used as reference drug. No significant changes were noted in heart rate after RR treatment in SHR as well as in WKY rats. Glomerular filtration rate showed a significant increase after RR administration in WKY rats (P < 0.01) and a no significant increase in SHR rats. These results suggest that oral administration of aqueous RR extract exhibited antihypertensive and diuretic effects in SHR rats and diuretic action in WKY rats.

Acute diuretic effect of aqueous extract of Retama raetam in normal rats.

The purpose of this study was to examine the acute diuretic effect of the water extract of the aerial parts of Retama raetam (RR) at a dose of 5 mg/kg/h in normal rats. The aqueous extract was administered intravenously and the diuresis was followed within 4 h after starting the treatment. Intravenous administration of the aqueous RR extract produced a significant increment on diuresis from the second hour (p<0.01) to the fourth hour (p<0.001). Furosemide at a dose of 0.1 mg/kg/h had a similar effect when compared to RR administration. Parallel, the noticed increase of diuresis was associated with an elevation of glomerular filtration rate (p<0.05) and a significant decrease of urinary osmolarity (p<0.001). However, RR extract did not affect plasma urea levels, urine pH, plasma osmolarity and hematocrite. It is then concluded that the water extract of the aerial parts of RR exhibited a significant diuretic effect in normal rat.

Fraxinus excelsior L. evokes a hypotensive action in normal and spontaneously hypertensive rats.

The hypotensive effect of an aqueous extract of Fraxinus excelsior L. was investigated in both normotensive (WKY) and spontaneously hypertensive rats (SHR). Daily oral administration of Fraxinus excelsior (20 mg/kg) aqueous extract for 3 weeks produced a significant decrease in systolic blood pressure (SBP) with variation coefficient (Delta%) of 13.5% in SHR (p<0.01) and 9% in WKY rats (p<0.05). The aqueous extract of Fraxinus excelsior significantly enhanced the urination in both SHR (p<0.05 compared to control) and WKY (p<0.05 compared to control). Irbesartan (Avapro), an angiotensin II antagonist, was used as reference drug. Furthermore, oral administration of aqueous Fraxinus excelsior extract at a dose of 20 mg/kg produced a significant increase in urinary excretion of sodium (p<0.01 compared to control), potassium (p<0.001 compared to control) and chlorides (p<0.01) in SHR rats. In normal rats, the aqueous Fraxinus excelsior extract administration induced a significant increase of the urinary elimination of sodium (p<0.05 compared to control), chlorides (p<0.01 compared to control) and potassium (p<0.01 versus control). While there were no significant changes in heart rate (HR) after Fraxinus excelsior treatment in both SHR and WKY rats, glomerular filtration rate (GFR) showed a significant increase in SH rats (p<0.001) after Fraxinus excelsior treatment. These results suggest that oral administration of aqueous extract of Fraxinus excelsior exhibited hypotensive and diuretic actions.

Effect of Retama raetam on lipid metabolism in normal and recent-onset diabetic rats.

The purpose of this study was to examine the effect of single and repeated oral administration of the aqueous extract of Retama raetam (Forssk) Webb (RR) (20 mg/kg) on lipid metabolism in normal and streptozotocin-induced diabetic rats. In normal rats, the aqueous extract of RR induced a significant decrease of the plasma triglycerides concentrations one week after repeated oral administration (P<0.05). This reduction was maintained two weeks after once daily repeated oral administration (P<0.05). A significant decrease of plasma cholesterol levels was also observed one week (P<0.05) and two weeks (0.05) after repeated oral administration. In diabetic rats, RR treatment caused a significant decrease of plasma triglycerides levels after a single (P<0.05) and repeated (P<0.001) oral administration. A significant decrease of cholesterol levels was observed four hours after a single oral administration of the RR aqueous extract (P<0.05). One week after repeated oral administration of RR aqueous extract, the plasma cholesterol levels were significantly decreased (P<0.05) and still dropped after two weeks (P<0.005). On the other hand, the repeated oral administration of RR aqueous extract caused a significant decrease of body weight one week after repeated oral treatment in diabetic rats (P<0.05). We conclude that the aqueous extract of RR exhibits lipid and body weight lowering activities in both normal and severe hyperglycemic rats after repeated oral administration of RR aqueous extract at a dose of 20 mg/kg.

Effects of an aqueous extract of Triticum repens on lipid metabolism in normal and recent-onset diabetic rats.

The aim of this study was to demonstrate the effects of single and repeated oral administration of the aqueous rhizomes extract of Triticum repens (TR) (20 mg/kg) on lipid metabolism in normal and streptozotocin-induced diabetic rats. In normal rats, the aqueous extract of TR induced a significant decrease in the plasma triglycerides concentrations 4 days (P<0.05) and 1 week after repeated oral administration (P<0.05). This reduction was abolished 2 weeks after once daily repeated oral administration. A significant decrease of plasma cholesterol levels was observed only 1 week (P<0.05) after repeated oral administration. In diabetic rats, TR treatment caused a significant decrease in plasma triglycerides levels after a single (P<0.01) and repeated (P<0.001) oral administration. A strong decrease in cholesterol level was observed 6 h after a single oral administration of the aqueous extract TR (P<0.001). Four days after repeated oral administration of TR aqueous extract, the plasma cholesterol level was significantly decreased (P<0.05) and still dropped after 2 weeks (P<0.001). On other hand, the repeated oral administration of aqueous TR extract caused a significant decrease in body weight 2 weeks after repeated oral treatment in diabetic rats (P<0.05). We conclude that the aqueous extract of TR exhibits lipid and body weight lowering activities in severe hyperglycaemic rats after repeated oral administration of aqueous TR extract at a dose of 20 mg/kg.

Ethnobotanical survey of medicinal plants used for the treatment of diabetes, cardiac and renal diseases in the North centre region of Morocco (Fez-Boulemane).

In order to make an inventory of herbal remedies commonly used in the treatment of diabetes, hypertension and renal diseases in the North centre region of Morocco, 1527 patients (1095 diabetic patients, 274 with renal disorders and 158 with cardiac disorders) and 25 traditional herbal healers were interviewed in four different areas of Fez-Boulemane region. More than 1153 of the total patients interviewed (76%) used regularly medicinal plants to treat diabetes, cardiac and renal diseases. These data showed that phytotherapy has always be practiced in this region. All the persons interviewed have indicated that the reasons of using phytotherapy is that the plant medicines are cheapest (54%) and more efficient (38%) than modern medicine. They also reported that the result of phytotherapy is better (72%). Our survey started at May 1997. About 90 plants were cited (54 plants for diabetes, 11 for cardiac diseases, 19 for hypertension and 33 for renal diseases). The plants reported have been identified and are presented in a table with the vernacular name, useful parts, ecological distribution and medicinal uses. Only 12% of the total patients have a relative knowledge of the toxic plants. The result indicated that nine plants are extremely toxic at high doses and chronic treatment. Fifty nine percent of the interviewers have indicated that they used medicinal plants from the experience of the other.

Potentiation of urinary atrial natriuretic peptide interferes with macula densa function.

OBJECTIVES: Neutral endopeptidase (NEP) inhibition potentiated the renal action of Atrial Natriuretic Peptide (ANP) and was associated with appearance of the peptide in the urine, providing evidence of protection of the filtrated peptide along the course of the nephron. The macula densa, composed of epithelial cells, receives ionic information from the urinary compartment via Na-K-2Cl cotransport and influences renin secretion by the myoepithelioïd cells in the afferent arteriole. bNOS constitutively expressed in the epithelial cells of the macula densa is involved in this feed-back. NEP inhibition was associated with the absence of any increase in renin secretion. The hypothesis is that potentiation of urinary ANP by NEP inhibition could limit renin secretion by directly or indirectly targeting the macula densa in vivo. METHODS AND RESULTS: We tested the interaction between NEP inhibition (candoxatril) and Na-K-2Cl inhibition (bumetanide) on electrolyte and ANP urinary excretion, renin secretion, macula densa activity (NADPH diaphorase activity and bNOS mRNA) and TSC-1 mRNA expression in the renal cortex and BSC-1 in the renal medulla of rats treated for 5 days. Bumetanide increased urinary electrolyte excretion whereas candoxatril did not. Candoxatril increased urinary ANP and cyclic GMP excretion. Bumetanide increased renin and aldosterone secretion whereas candoxatril decreased renin secretion. This effect on renin release was associated with an increase in macula densa NADPH diaphorase activity in the bumetanide-treated group which was blunted by candoxatril. Lastly, bumetanide increased TSC-1 mRNA expression in the cortex and this effect was blunted by candoxatril. CONCLUSION: These results suggest that potentiation of ANP by NEP inhibition could interfere with tubular function at different levels and limit renin secretion by a urinary pathway involving macula densa activity.

Experimental diuretic effects of Rosmarinus officinalis and Centaurium erythraea.

Herbal remedies are widely used in Moroccan pharmacopoeia. We assessed the diuretic effect of two medicinal plants: Rosmarinus officinalis L., Labiatae, and Centaurium erythraea L., Gentianaceae, both reputed for the treatment of urinary ailments. To determine the action of these herbs on urinary volume (UV) and the excretion of sodium (U(Na)V), potassium (U(K)V), and chloride (U(Cl)V), the aqueous extracts of both plants were administered daily to Wistar rats for 1 week. The concentration of electrolytes and urea in plasma and creatinine clearance were also investigated. Daily oral administration of the aqueous extracts of R. officinalis and C. erythraea at the dose of 10 ml/kg of 8 or 16% extract in distilled water significantly enhanced diuresis in rats compared to the control group from the fifth day of treatment. For R. officinalis at the dose of 8% the peak of urinary excretion of sodium, potassium and chloride was reached after 6 days of treatment (P<0.001). The aqueous extract of of R. officinalis at the dose of 16% did not significantly affect the excretion of water and electrolytes over a similar period but slight increases in urinary excretion of sodium and chloride on the seventh day and of potassium on the sixth day (P<0.05) were observed. No increase was recorded for 24 h urinary excretion of Na+, K+ and Cl- during the first 4 days of treatment for the groups treated with C. erythraea at the doses of 8 and 16% whereas their effects on the same parameters were highly significant thereafter. No change was observed in plasma electrolytes and urea in any group, except for a decrease in sodium and chloride concentration in the group treated with 16% of R. officinalis. A decrease in creatinine clearance was demonstrated after treatment with 8% of R. officinalis and C. erythraea. Our findings demonstrate a diuretic effect of aqueous extracts of R. officinalis L. and C. erythraea L. with the most effective dose for water and electrolyte excretion being 8% for both plants.

[Functional compartmentation of the endocrine action of cardiac natriuretic peptides]. / Compartimentation fonctionnelle de l'action endocrine des peptides natriurétiques cardiaques.

The endocrine function of the heart is to secrete Atrial and Brain natriuretic -peptides (ANP and BNP). These peptides are biologically active via particulate guanylate cyclases which generate cyclic GMP, the second intracellular messenger. A polysaccharide antagonist, HS-142-1 has been recently described by a Japanese Group. Cyclic GMP is partly secreted from the target cells into the extra cellular medium in which its accumulation is proportional to the concentration of the natriuretic peptide. Neutral Endopeptidase (NEP) is a zinc ectoenzyme involved in the catabolism of natriuretic peptides. NEP is absent in plasma but present on the surface of endothelial and smooth muscle cells. NEP is mainly expressed at the apical pole of the epithelial cells of the proximal tubule in the nephron. Chronic increase in volume and pressure within the cardiac cavities is associated with the oversecretion of natriuretic peptides. This chronic phenomenon involves the recruitment of all the cardiac myocytes to express natriuretic peptide genes. The clinical application of this hyperplasic phenomenon is congestive heart failure, in which the plasma levels of natriuretic peptides correlate with the level of the -hemodynamic stress. Therefore the plasma levels of natriuretic peptides are good pronostic markers in both experimental and human heart failure. The degree of congestive heart failure as well as the plasma levels of ANP and BNP are also -correlated with the plasma and urinary levels of cyclic GMP. The plasma level of -cyclic GMP is correlated with the endothelial concentration of cyclic GMP but not with the cyclic GMP concentration in smooth muscle cells. From these experimental data, we can conclude that plasma cyclic GMP originates from endothelial cells and is related to particulate guanylate cyclase activity. In contrast natriuretic peptides do not modulate vascular wall cyclic GMP content. The natriuretic action of ANP is probably due to the interaction of the filtered peptide with the particulate guanylate cyclase at the apical pole of the epithelial cells. The apparition of peptiduria associated with natriuresis during NEP inhibition provides evidence of the action of the peptide in the urinary compartment. It is also by a urinary pathway via the macula densa that ANP, and its potentiation by NEP inhibition, decreases renin secretion. The fact that plasma levels of ANP and plasma and urine levels of cyclic GMP correlate with the degree of salt retention in congestive heart failure, provides evidence for chronic desensitization of the system. An up-regulation of Na(+), K(+), 2Cl(-) expression associated with experimental congestive heart failure has recently been shown. Similarly, a modulation of the different sodium transporter systems along the nephron could be one of the counter-regulations leading to desensitization to natriuretic peptides. In conclusion, natriuretic peptides are true endocrine peptides, secreted by the heart, transported in the plasma, filtered by the glomeruli and active at the nephron level. The molecular effector of ANP and cyclic GMP in the epithelial cells is probably the G-kinase II, isoform phosphorylating the cystic fibrosis transmembrane conductance regulator (CFTR). The exact mechanism of desensitization remains to be elucidated.