Abstract
1. Vascular vasopressin receptors are understood because of the specific application of each major technical advance in pharmacology; this review shows that isolated organs, whole animal preparations, hormone synthesis, radioligand binding, and human studies have all played their part. 2. Even so, neither vascular vasopressin receptor heterogeneity nor occupancy-response relationships are fully understood; by way of comparison far more is known about alpha-adrenoceptors. 3. The biochemical pharmacology of vascular vasopressin receptor activation is still in its infancy. Whilst the second messenger molecules resulting from vascular vasopressin receptor activation appear to be component(s) of the pathways of phosphoinositide metabolism, technical difficulties have led investigators to study similar vasopressin receptors in other tissues. 4. It is not certain, for example, that results from hepatic vasopressin receptor studies can be automatically extrapolated to vascular smooth muscle. 5. Lastly, the directions that vascular vasopressin research might take are speculated on. It is not known whether the vascular vasopressin receptor is itself a polymer, whether receptor heterogeneity could be exploited in the clinical uses of vasopressins, nor whether vasopressins are co-released with other neurotransmitters.
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