ABSTRACT
Ethanol has various effects on male sexual activity under the influence of direct and indirect, in acute and chronic alcohol ingestion. However, whether acetaldehyde, a principal metabolite of ethanol, may affect penile erection directly has still not been elucidated. This present study was, therefore, designed to clarify the pharmacologic effects of the acetaldehyde on corpus cavernosal smooth muscle. Corpus cavernosal strips were prepared from rabbit penises. Isometric tension changes of rabbit corpus cavernosal strips to various drugs and electrical field stimulation (EFS) in an organ chamber were recorded with a pressure transducer after active muscle tone had been induced by phenylephrine (10(-5) mol/L). At the concentrations employed, acetaldehyde had no effect on the pH of the bathing medium. Acetaldehyde in each concentration did not significantly affect resting tone of the smooth muscle during 30 min incubation. Acetaldehyde suppressed contractility induced by phenylephrine and KCI at 10(-4) mol/L, and relaxation induced by EFS and bethanechol at 10(-3) mol/L and 10(-4) mol/L respectively, but acetaldehyde enhanced relaxation induced by ATP at high acetaldehyde level. Sodium nitroprusside-induced relaxation was not affected at any employed acetaldehyde concentration. This suggests that increasing the acetaldehyde level may contribute to male erectile dysfunction mainly by the inhibition of nitric oxide formation.
Subject(s)
Male , Rabbits , Acetaldehyde/pharmacology , Animals , Bethanechol/pharmacology , In Vitro Techniques , Muscle Contraction/drug effects , Muscle Relaxation/drug effects , Muscle, Smooth/physiology , Muscle, Smooth/drug effects , Nitroprusside/pharmacology , Penis/physiology , Penis/drug effects , Phenylephrine/pharmacology , Potassium Chloride/pharmacologyABSTRACT
Ethanol has various effects on male sexual activity under the influence of direct and indirect, in acute and chronic alcohol ingestion. However, whether acetaldehyde, a principal metabolite of ethanol, may affect penile erection directly has still not been elucidated. This present study was, therefore, designed to clarify the pharmacologic effects of the acetaldehyde on corpus cavernosal smooth muscle. Corpus cavernosal strips were prepared from rabbit penises. Isometric tension changes of rabbit corpus cavernosal strips to various drugs and electrical field stimulation (EFS) in an organ chamber were recorded with a pressure transducer after active muscle tone had been induced by phenylephrine (10(-5) mol/L). At the concentrations employed, acetaldehyde had no effect on the pH of the bathing medium. Acetaldehyde in each concentration did not significantly affect resting tone of the smooth muscle during 30 min incubation. Acetaldehyde suppressed contractility induced by phenylephrine and KCI at 10(-4) mol/L, and relaxation induced by EFS and bethanechol at 10(-3) mol/L and 10(-4) mol/L respectively, but acetaldehyde enhanced relaxation induced by ATP at high acetaldehyde level. Sodium nitroprusside-induced relaxation was not affected at any employed acetaldehyde concentration. This suggests that increasing the acetaldehyde level may contribute to male erectile dysfunction mainly by the inhibition of nitric oxide formation.
Subject(s)
Male , Rabbits , Acetaldehyde/pharmacology , Animals , Bethanechol/pharmacology , In Vitro Techniques , Muscle Contraction/drug effects , Muscle Relaxation/drug effects , Muscle, Smooth/physiology , Muscle, Smooth/drug effects , Nitroprusside/pharmacology , Penis/physiology , Penis/drug effects , Phenylephrine/pharmacology , Potassium Chloride/pharmacologyABSTRACT
The effects of histamine, bethanechol and pentagastrin on gastric acid secretion were studied in rats of younger and older age groups. After 48 hours starvation, the pylorus was ligated and each of the secretagogues was administered subcutaneously to individual groups. Four hours later the animals were sacrified by chloroform-induced asphyxia and the stomach was removed after ligating the cardiac end. The stomach contents, obtained by flushing with 3 ml of distilled water, were used to determine the volume of gastric juice and its free and total acidity. Histamine and bethanechol produced a greater increase in the volume and acidity of gastric juice in older animals as compared to younger ones. Pentagastrin also produced greater increase in these parameters in older animals but it was not statistically significant. Possible explanation of these results include variable size of parietal cell mass and/or difference in the sensitivity of parietal cells to individual secretagogues in animals of different age groups