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José Melena - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefe's Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds. Methods Experiments were conducted in albino ocular normotensive and hypertensive rabbits by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined, in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics. Results All natural ergot alkaloids tested reduced intraocular pressure in a dose-related fashion. The ocular hypotensive effect was greater in α-chymotrypsin-induced ocular hypertensive rabbits for the three compounds tested. All natural ergot alkaloids tested decreased both tonographic outflow facility and, to a greater extent, aqueous humor inflow in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Conclusion Taken together, our data suggest that these compounds decrease both tonographic outflow facility and, to a greater extent, aqueous humor inflow, which explains their final effect in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Reductions in aqueous humor inflow observed after topical application of natural ergot alkaloids in α-chymotrypsin-induced ocular hypertensive rabbits can only be explained by a marked inhibition of active secretion of aqueous humor, since processes involved in aqueous humor formation may probably be altered after α-chymotrypsin injection.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefes Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds.
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The effect of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in rabbits with α-chymotrypsin-induced ocular hypertension
Graefe's Archive for Clinical and Experimental Ophthalmology, 2002Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background: We previously reported that topical natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive rabbits, most likely by decreasing aqueous humor inflow. In the present study, the effects of these compounds on intraocular pressure and aqueous humor dynamics in a rabbit model for ocular hypertension were assessed. Methods: Experiments were conducted in albino rabbits made ocular hypertensive by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics in α-chymotrypsin-induced ocular hypertensive rabbits. Results: Topical application of the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine lowered intraocular pressure in α-chymotrypsin-induced ocular hypertensive rabbits in a dose-related fashion, with ergocristine displaying the greatest intraocular pressure-lowering effect. Tonographic studies revealed a decrease in the tonographic outflow facility following topical application of natural ergot alkaloids, although only the effects of both ergocristine and α-Ergocryptine reached statistical significance. All natural ergot alkaloids tested significantly reduced the calculated aqueous humor inflow. Conclusion: This study suggests that the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine effectively decrease intraocular pressure in the α-chymotrypsin-induced model of ocular hypertension. Since these compounds reduce the tonographic aqueous humor outflow facility, their final ocular antihypertensive effect appears to result from a remarkable reduction of the aqueous humor inflow.
Gustavo Puras - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefe's Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds. Methods Experiments were conducted in albino ocular normotensive and hypertensive rabbits by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined, in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics. Results All natural ergot alkaloids tested reduced intraocular pressure in a dose-related fashion. The ocular hypotensive effect was greater in α-chymotrypsin-induced ocular hypertensive rabbits for the three compounds tested. All natural ergot alkaloids tested decreased both tonographic outflow facility and, to a greater extent, aqueous humor inflow in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Conclusion Taken together, our data suggest that these compounds decrease both tonographic outflow facility and, to a greater extent, aqueous humor inflow, which explains their final effect in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Reductions in aqueous humor inflow observed after topical application of natural ergot alkaloids in α-chymotrypsin-induced ocular hypertensive rabbits can only be explained by a marked inhibition of active secretion of aqueous humor, since processes involved in aqueous humor formation may probably be altered after α-chymotrypsin injection.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefes Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds.
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The effect of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in rabbits with α-chymotrypsin-induced ocular hypertension
Graefe's Archive for Clinical and Experimental Ophthalmology, 2002Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background: We previously reported that topical natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive rabbits, most likely by decreasing aqueous humor inflow. In the present study, the effects of these compounds on intraocular pressure and aqueous humor dynamics in a rabbit model for ocular hypertension were assessed. Methods: Experiments were conducted in albino rabbits made ocular hypertensive by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics in α-chymotrypsin-induced ocular hypertensive rabbits. Results: Topical application of the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine lowered intraocular pressure in α-chymotrypsin-induced ocular hypertensive rabbits in a dose-related fashion, with ergocristine displaying the greatest intraocular pressure-lowering effect. Tonographic studies revealed a decrease in the tonographic outflow facility following topical application of natural ergot alkaloids, although only the effects of both ergocristine and α-Ergocryptine reached statistical significance. All natural ergot alkaloids tested significantly reduced the calculated aqueous humor inflow. Conclusion: This study suggests that the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine effectively decrease intraocular pressure in the α-chymotrypsin-induced model of ocular hypertension. Since these compounds reduce the tonographic aqueous humor outflow facility, their final ocular antihypertensive effect appears to result from a remarkable reduction of the aqueous humor inflow.
G J A Speijers - One of the best experts on this subject based on the ideXlab platform.
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subacute toxicity of α Ergocryptine in sprague dawley rats 1 general toxicological effects
Food and Chemical Toxicology, 2000Co-Authors: G B Janssen, R B Beems, G J A Speijers, H P Van EgmondAbstract:The dietary subacute toxicity of the ergot alkaloid α-Ergocryptine was studied in Sprague–Dawley rats. Rats were fed 0, 4, 20, 100 or 500 mg Ergocryptine/kg diet for 28–32 days (equal to 0, 0.36, 1.7, 8.9 and 60 mg Ergocryptine/kg body weight/day for females and 0, 0.34, 1.4, 6.6 and 44 mg Ergocryptine/kg body weight/day for males). The present study describes the general toxicological effects; the effects on metabolic and hormonal parameters will be reported separately. Body weight, body weight gain, food intake and food efficiency were all decreased with a U-shaped dose–response curve, as in both sexes the ranking severity of effects was in the order 100–20–500 and 4 mg/kg diet. Other changes with a U-shaped dose–response relationship included: hematological parameters (decreased MCV and MCH), serum enzyme activities (slightly increased/decreased ALAT, ASAT, GGT), increased serum urea concentrations, decreased glomular filtration (creatinine and urea clearances), decreased absolute organ weights, increased and decreased relative organ weights, atrophy of thymus and in females atrophy of ovary and uterus with in the mid-dose groups no detectable morphological features of an oestric cycle in the uterus. Other parameters, including increased relative liver, heart and ovarian weights and necrosis of the tail, were influenced in a dose-related manner or only in the high dose group. The U-shaped changes for the parameters mentioned above might be caused by the U-shaped dose–response relationship for food intake, which may be explained by the dopaminergic properties of α-Ergocryptine. It is concluded that in rats fed Ergocryptine for 28 days the dose–effect curve is rather steep and that the NOAEL is 4 mg/kg diet.
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subacute toxicity of α Ergocryptine in sprague dawley rats 2 metabolic and hormonal changes
Food and Chemical Toxicology, 2000Co-Authors: G B Janssen, R B Beems, L H Elvers, G J A SpeijersAbstract:Abstract The present study describes the metabolic changes observed in a dietary subacute toxicity experiment with the ergot alkaloid α-Ergocryptine in Sprague–Dawley rats. The observed effects on metabolic and hormonal parameters were described separately from the general toxicological effects, in view of the important role of dopamine agonists in metabolism (e.g. ergot alkaloids in fescue toxicosis). The rats were fed 0, 4, 20, 100 or 500 mg Ergocryptine/kg diet for 28–32 days (equal to 0, 0.36, 1.7, 8.9 and 60 mg Ergocryptine/kg body weight/day for females and 0, 0.34, 1.4, 6.6 and 44 mg Ergocryptine/kg body weight/day for males). Total cholesterol and high-density lipoprotein (HDL)-cholesterol were decreased dose dependently in females but the ratio HDL-cholesterol/total cholesterol was only decreased at 20 mg/kg body weight. Triglycerides and glucose concentrations were decreased in the highest dose groups of both sexes. Serum urea concentrations were increased in the 20, 100 and 500 mg/kg dose groups. Insulin, glucagon and liver glycogen were increased in the highest dose group at the end of the study, when the animals were allowed to eat prior to blood sampling and necropsy. Prolactin, T4 and FT4 were decreased in the 20, 100 and 500 mg/kg dose groups of both sexes. Follicle-stimulating hormone (FSH) was decreased in the 20, 100 and 500 mg/kg female dose groups and luteinizing hormone (LH) was increased in the 20, 100 and 500 mg/kg male dose groups. It is postulated that the observed effects on food intake, metabolism (lipid and carbohydrate) and hormonal parameters are due to an interaction of Ergocryptine with central dopaminergic activities, which comprise a major functional component of a central regulatory system for metabolism.
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Subacute toxicity of α-Ergocryptine in Sprague–Dawley rats. 2: metabolic and hormonal changes
Food and Chemical Toxicology, 2000Co-Authors: G B Janssen, L H Elvers, Beems Rb, G J A SpeijersAbstract:Abstract The present study describes the metabolic changes observed in a dietary subacute toxicity experiment with the ergot alkaloid α-Ergocryptine in Sprague–Dawley rats. The observed effects on metabolic and hormonal parameters were described separately from the general toxicological effects, in view of the important role of dopamine agonists in metabolism (e.g. ergot alkaloids in fescue toxicosis). The rats were fed 0, 4, 20, 100 or 500 mg Ergocryptine/kg diet for 28–32 days (equal to 0, 0.36, 1.7, 8.9 and 60 mg Ergocryptine/kg body weight/day for females and 0, 0.34, 1.4, 6.6 and 44 mg Ergocryptine/kg body weight/day for males). Total cholesterol and high-density lipoprotein (HDL)-cholesterol were decreased dose dependently in females but the ratio HDL-cholesterol/total cholesterol was only decreased at 20 mg/kg body weight. Triglycerides and glucose concentrations were decreased in the highest dose groups of both sexes. Serum urea concentrations were increased in the 20, 100 and 500 mg/kg dose groups. Insulin, glucagon and liver glycogen were increased in the highest dose group at the end of the study, when the animals were allowed to eat prior to blood sampling and necropsy. Prolactin, T4 and FT4 were decreased in the 20, 100 and 500 mg/kg dose groups of both sexes. Follicle-stimulating hormone (FSH) was decreased in the 20, 100 and 500 mg/kg female dose groups and luteinizing hormone (LH) was increased in the 20, 100 and 500 mg/kg male dose groups. It is postulated that the observed effects on food intake, metabolism (lipid and carbohydrate) and hormonal parameters are due to an interaction of Ergocryptine with central dopaminergic activities, which comprise a major functional component of a central regulatory system for metabolism.
José Segarra - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefe's Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds. Methods Experiments were conducted in albino ocular normotensive and hypertensive rabbits by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined, in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics. Results All natural ergot alkaloids tested reduced intraocular pressure in a dose-related fashion. The ocular hypotensive effect was greater in α-chymotrypsin-induced ocular hypertensive rabbits for the three compounds tested. All natural ergot alkaloids tested decreased both tonographic outflow facility and, to a greater extent, aqueous humor inflow in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Conclusion Taken together, our data suggest that these compounds decrease both tonographic outflow facility and, to a greater extent, aqueous humor inflow, which explains their final effect in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Reductions in aqueous humor inflow observed after topical application of natural ergot alkaloids in α-chymotrypsin-induced ocular hypertensive rabbits can only be explained by a marked inhibition of active secretion of aqueous humor, since processes involved in aqueous humor formation may probably be altered after α-chymotrypsin injection.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefes Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds.
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The effect of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in rabbits with α-chymotrypsin-induced ocular hypertension
Graefe's Archive for Clinical and Experimental Ophthalmology, 2002Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background: We previously reported that topical natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive rabbits, most likely by decreasing aqueous humor inflow. In the present study, the effects of these compounds on intraocular pressure and aqueous humor dynamics in a rabbit model for ocular hypertension were assessed. Methods: Experiments were conducted in albino rabbits made ocular hypertensive by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics in α-chymotrypsin-induced ocular hypertensive rabbits. Results: Topical application of the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine lowered intraocular pressure in α-chymotrypsin-induced ocular hypertensive rabbits in a dose-related fashion, with ergocristine displaying the greatest intraocular pressure-lowering effect. Tonographic studies revealed a decrease in the tonographic outflow facility following topical application of natural ergot alkaloids, although only the effects of both ergocristine and α-Ergocryptine reached statistical significance. All natural ergot alkaloids tested significantly reduced the calculated aqueous humor inflow. Conclusion: This study suggests that the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine effectively decrease intraocular pressure in the α-chymotrypsin-induced model of ocular hypertension. Since these compounds reduce the tonographic aqueous humor outflow facility, their final ocular antihypertensive effect appears to result from a remarkable reduction of the aqueous humor inflow.
Juan Santafé - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefe's Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds. Methods Experiments were conducted in albino ocular normotensive and hypertensive rabbits by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined, in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics. Results All natural ergot alkaloids tested reduced intraocular pressure in a dose-related fashion. The ocular hypotensive effect was greater in α-chymotrypsin-induced ocular hypertensive rabbits for the three compounds tested. All natural ergot alkaloids tested decreased both tonographic outflow facility and, to a greater extent, aqueous humor inflow in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Conclusion Taken together, our data suggest that these compounds decrease both tonographic outflow facility and, to a greater extent, aqueous humor inflow, which explains their final effect in ocular normotensive and in α-chymotrypsin-induced ocular hypertensive rabbits. Reductions in aqueous humor inflow observed after topical application of natural ergot alkaloids in α-chymotrypsin-induced ocular hypertensive rabbits can only be explained by a marked inhibition of active secretion of aqueous humor, since processes involved in aqueous humor formation may probably be altered after α-chymotrypsin injection.
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A comparative study of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in oclular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits
Graefes Archive for Clinical and Experimental Ophthalmology, 2007Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background Although it has been suggested that ergot derivatives may play a role in antiglaucoma therapy, little attention has been paid to the ocular hypotensive action of these drugs. Having previously reported that topical natural ergot alkaloids ergocristine α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, the aim of the present work was to compare the effect of ergocristine, α-Ergocryptine and ergocornine on the intraocular pressure and aqueous humor dynamics in ocular normotensive and α-chymotrypsin-induced ocular hypertensive rabbits, in order to further explore the ocular actions of these compounds.
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The effect of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in rabbits with α-chymotrypsin-induced ocular hypertension
Graefe's Archive for Clinical and Experimental Ophthalmology, 2002Co-Authors: Gustavo Puras, Juan Santafé, Manuel Garrido, José Segarra, José MelenaAbstract:Background: We previously reported that topical natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive rabbits, most likely by decreasing aqueous humor inflow. In the present study, the effects of these compounds on intraocular pressure and aqueous humor dynamics in a rabbit model for ocular hypertension were assessed. Methods: Experiments were conducted in albino rabbits made ocular hypertensive by intracameral injection of α-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined in order to obtain dose–response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics in α-chymotrypsin-induced ocular hypertensive rabbits. Results: Topical application of the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine lowered intraocular pressure in α-chymotrypsin-induced ocular hypertensive rabbits in a dose-related fashion, with ergocristine displaying the greatest intraocular pressure-lowering effect. Tonographic studies revealed a decrease in the tonographic outflow facility following topical application of natural ergot alkaloids, although only the effects of both ergocristine and α-Ergocryptine reached statistical significance. All natural ergot alkaloids tested significantly reduced the calculated aqueous humor inflow. Conclusion: This study suggests that the natural ergot alkaloids ergocristine, α-Ergocryptine and ergocornine effectively decrease intraocular pressure in the α-chymotrypsin-induced model of ocular hypertension. Since these compounds reduce the tonographic aqueous humor outflow facility, their final ocular antihypertensive effect appears to result from a remarkable reduction of the aqueous humor inflow.