Key result
In vitro sensitivity of rat thoracic aorta rings to potassium chloride and phenylephrine exhibited significant time-dependent variations depending on the time of tissue extraction.
The time of tissue harvesting significantly affects the in vitro sensitivity of vascular smooth muscle to contractile agents, highlighting the need for temporal standardization in experimental designs.
In this study, time-dependent variations in the in vitro sensitivity of rat thoracic aorta rings to potassium chloride (KCl) and phenylephrine (Phe) were investigated. Animals were synchronized with a 12h light and 12h darkness (lights on 08:00-20:00) schedule, and thoracic aortas were obtained at six different times of the day (1, 5, 9, 13, 17, and 21 hours after lights on). In order to avoid endothelial influence, all experiments were performed in endothelium-denuded preparations. Responses to KCI showed time-dependent variations in all the concentrations used. Phe-induced contractions also exhibited time-dependent differences. The rhythmic pattern of Phe responses did not change with the presence of the alpha1-adrenergic antagonist prazosin. In addition, both the EC50 values of KCl and Phe, and also the K(B) values of prazosin, displayed rhythmicity. In conclusion, time of obtaining tissues is an important factor for experimental standardization in, at least, vascular smooth muscle preparations.
No takes yet. Share an insight, caveat, or question.
Görgün et al. (1998) studied this question. Time of day of tissue extraction was evaluated on Responses to potassium chloride and phenylephrine (EC50 and K(B) values). In vitro sensitivity of rat thoracic aorta rings to potassium chloride and phenylephrine exhibited significant time-dependent variations depending on the time of tissue extraction.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: