Quantitative study of alpha-adrenergic receptors in circular and longitudinal muscle of isthmus of rabbit fallopian tube and in rabbit aorta.
The affinity of phenylephrine (pD2 value) and KB value for phentolamine for the alpha-adrenergic receptors of circular and longitudinal muscle of isthmus of rabbit fallopian tube and rabbit aorta have been estimated. The affinity of both phenylephrine and phentolamine was significantly more for the alpha adrenoceptors of the longitudinal muscle of isthmus of rabbit fallopian tube and rabbit aorta than circular muscle of isthmus of fallopian tube. The results of this investigation suggest that alpha adrenoceptors of circular muscle of isthmus are atypical. If this holds good for the human fallopian tube, the development of selective alpha-adrenergic-receptor agonists and antagonists may be of potential practical application for the control of fertility.