Y. Saitoh, Y. Irie, T. Hosokawa
1978
Citations
0
Influential Citations
10
Citations
Quality indicators
Journal
Biochemical pharmacology
Abstract
Abstract Intravenous injection of 5-(1-hydroxy-2-isopropylaminobutyl)-8-hydroxycarbostyril hydrochioride hemihydrate (procaterol) or isoproterenol into fasted rats caused increases in blood levels of glucose, lactate, free fatty acids (FFA), glycerol, immunoreactive insulin and cyclic AMP. Procaterolinduced alterations of these metabolic parameters, other than FFA, were durable; the increases were observable over a period longer than 2 hr, in contrast to a much shorter duration of isoproterenol-induced metabolic changes. These actions of procaterol were antagonized by propranolol, were observed in adrenodemedullated rats, and were enhanced by theophylline. It is thought therefore, that metabolic changes induced by procaterol are actually mediated via β-adrenoceptors, as are its pharmacological actions. Procaterol caused hyperlactacidemia at molar doses ten to one hundred times lower than those required for isoproterenol, trimetoquinol or salbutamol. A much higher dose of procaterol was required to increase blood levels of FFA, glycerol and insulin. In view of our findings that butoxamine, a selective β 2 -adrenoceptor antagonist, antagonized the isoproterenol-induced blood lactate, while practolol, a selective 1 -antagonist, effectively inhibited the stimulatory actions of isoproterenol on FFA, glycerol and insulin, it is concluded that procaterol is a more selective 2 -adrenoceptor agonist than isoproterenol or trimetoquinol, and is more potent than salbutamol.