Beta1 and beta2 receptor mechanisms in rat jugular veins: Differences between norepinephrine and isoproterenol-induced relaxation

DEMONSTRATION OF BOTH β1‐ AND β2‐ADRENOCEPTORS MEDIATING RELAXATION OF ISOLATED RING PREPARATIONS OF RAT PULMONARY ARTERY

“…the renal vascular bed (Tairi, Yabuuchi & Yamashita, 1977) and in the vasculature supplying adipose tissue (Belfrage, 1978), the different 3-adrenoceptor subtypes could have been in different blood vessel types. The demonstration of PI as well as P2-adrenoceptors in isolated preparations of rat pulmonary artery (present study), rat jugular vein and rat portal vein (Cohen & Wiley, 1978) …”

“…Determination of relative potency values would reveal only the predominant 11-adrenoceptor type present and a different approach is needed to demonstrate a mixed 3-adrenoceptor population. So far the only isolated blood vessels in which a mixed P-adrenoceptor population has been demonstrated are rat jugular and rat portal veins (Cohen & Wiley, 1978). The present study has been carried out on a rat artery preparation, the pulmonary artery, a blood vessel in which the Jadrenoceptor subtype(s) has not previously been classified.…”

β‐Adrenoceptor heterogeneity in guinea‐pig airways: comparison of functional and receptor labelling studies

“…Substantial recent evidence from both functional and receptor binding studies suggests that both Padrenoceptor subtypes can co-exist in tissues such as heart (Carlsson et al, 1972;Hedberg, Minneman & Molinoff, 1980), lung (Furchgott, 1976;Rugg et al, 1978; 1979), rat jugular vein (Cohen & Wiley, 1978) or cat nictitating membrane (Varma & Nickerson, 1981). However, there is no reason to expect that the direct identification of both P-adrenoceptor subtypes in a tissue should necessarily be accompanied by functional heterogeneity and there are good examples of this kind of discrepancy in guinea-pig atria (O'Donnell & Wanstall, 1979;Hedberg et al, 1980) and in the present study, at least in the case of peripheral lung tissue.…”

The classification of β‐adrenoceptors in isolated ring preparations of canine coronary arteries

“…In the present study, isolated ring preparations of three of the larger coronary arteries from dog, i.e. left circumflex artery, one of its ventricular branches and the septal branch of the left coronary artery, have been examined to see whether relaxant responses might be mediated by both 13l-and 12-adrenoceptors, as has been described for other blood vessels (Cohen & Wiley, 1978;O'Donnell & Wanstall, 1981a;1984). The method used has been described by O'Donnell & Wanstall (1981b).…”