Vasopressin and angiotensin II receptors in rat aortic smooth muscle cells in culture.
Rat aortic smooth muscle cells were isolated and maintained in primary culture. After 2-3 days, cells recovered their contractile phenotype and could be induced to contract in response to vasopressin and angiotensin II. Vasopressin- and angiotensin-specific binding sites were detected on these cells, using tritiated Lys8-vasopressin, Asn1-Val5-angiotensin II, and Sarc1-Ile8-angiotensin II. Vasopressin binding sites had Kd values of 30 and 12 nM for Lys8-and Arg8-vasopressin, respectively, and a maximal binding capacity of 25,000 sites/cell. They displayed several of the expected characteristics of vasopressin receptors involved in the vasopressor response in vivo. A highly significant correlation was found between the relative agonistic or antagonistic vasopressor potencies of a series of vasopressin structural analogues and their relative abilities to inhibit [3H]vasopressin binding to aortic smooth muscle cells. Specific binding sites for Asn1-Val5-angiotensin II and Sarc1-Ile8-angiotensin II had the following characteristics: Kd = 2.3 and 1.3 nM, respectively; maximal capacity: 50,000 sites/cell. Vasopressin and angiotensin did not modify the intracellular cyclic AMP content of aortic smooth muscle cells.
D015059:1-Sarcosine-8-Isoleucine Angiotensin II / Q000378:metabolism; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001011:Aorta; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D007700:Kinetics; D008297:Male; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011945:Receptors, Angiotensin / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017483:Receptors, Vasopressin; D014667:Vasopressins / Q000378:metabolism
D011945:Receptors, Angiotensin; D011956:Receptors, Cell Surface; D017483:Receptors, Vasopressin; D014667:Vasopressins; D000804:Angiotensin II; D015059:1-Sarcosine-8-Isoleucine Angiotensin II; D000242:Cyclic AMP