Peripheral adrenergic subsensitivity in adult rats undernourished at perinatal age

The reactivity to NA was studied in vas deferens and atrial preparations from adult rats undernourished at perinatal age. The contractile response on isolated vas deferens was markedly reduced in experimental preparations as compared with controls; however, the maximal contractile response elicited by Ba++ did not differ between them. Furthermore, the positive chronotropic effect of NA on isolated atria was significantly lower in preparations from deprived animals. The specific beta adrenergic receptor binding was significantly reduced in the hearts of experimental animals as compared with controls, without changes in receptor affinity. These results demonstrated that, in addition to changes in reactivity on vascular bed previously described, perinatal undernutrition produces a subsensitivity to adrenergic agonist on other peripheral sympathetic innervated tissues, as vas deferens and heart. This subsensitivity may be the consequence of a reduction in the number of adrenergic receptors caused by early malnutrition.