Use of Isolated Strips of Cat Spleen for the Assay of α-Adrenergic Blocking Compounds

A Study on the Contraction of Spleen Strips in Kids and Dogs, With Special Reference to the Cholinergic and Adrenergic Receptors

“…The concentration of isoproterenol sufficient to relax the mouse spleen has been rep o °ted to be 5 x 10-1° M (4), but it is not sufficient to change the isotonic tonus of the spleen strips in kids and dogs. The presence of the alpha-adrenergic receptors in the spleni c smooth muscles has been confirmed by several investigators (1,5,6,11,14). I n kid and dog-spleen strips, isopro terenol seems to stimulate the alpha-adrenergic receptors to produce contraction: in the first place, the concentrations of isoproterenol about 1,000 times higher than those of nor adrenaline are required to produce a moderate degree of contraction; in the second place, the isoproterenol and noradrenaline-induced contraction can be inhibited specifically by dibenamine in the concentration of 10-'; and in the third place, propranolol in the concentration of 10-' does not inhibit the isoproterenol-induced contraction in the dog or slightly inhibits in the kid.…”

The Β-Adrenergic RESPONSES IN ISOLATED SPLENIC CAPSULE AREA OF SEVERAL SPECIES OF ANIMALS

“…Catecholamines induce contraction on isolated or in vivo spleen tissues including smooth muscle areas of vessels and the capsule from various species (1)(2)(3)(4)(5)(6)(7)(8). This contraction was identified to be the response from the stimulation of a-adrenergic receptors.…”

The Blocking Action of Pronethalol on the Contraction of Isolated Spleen Strips Produced by Adrenaline, Acetylcholine or Isoproterenol

“…The adrenaline-induced contraction of the spleen strips can be block ed by alpha-adrenergic blocking agents (1)(2)(3)(4). According to Bickerton (4), isoproterenol, which stimulates beta-adrenergic receptors, also contracts the spleen strips and the iso proterenol-induced contraction is specifically blocked by a beta-adrenergic blocking agent, dichloroisoproterenol (5).…”