On the Role of Receptor-Receptor Interactions in Central Cardiovascular Regulation: Functional Studies on the Interactions between α2-adrenergic and Neuropeptide Y Receptors in the Rat Medulla Oblongata

  • Anders Härfstrand
  • Kjell Fuxe
  • Luigi F. Agnati
Part of the Wenner-Gren Center International Symposium Series book series (WGS)


α2-adrenergic receptors and neuropeptide Y (NPY) receptors have been shown to overlap within the cardiovascular subnuclei of the nucleus tractus solitarius (nTS) of the male rat (see Fuxe et al., 1986, Härfstrand et al., 1986a and Fuxe et al., this symposium). Large numbers of phenylethanolamine-N-methyltransferase (PMNT) (Hökfelt et al., 1973, 1974, 1984) and NPY immunoreactive (IR) nerve terminals have also been demonstrated within the nTS (Hökfelt et al., 1983a, b; Everitt et al., 1984; Härfstrand et al., 1986b; Chronwall et al., 1985) and many PNMT/NPY costoring nerve terminals exist in this region (Fuxe et al., 1985). Hökfelt and colleagues (Hökfelt et al., 1983a, b) have shown coexistence of NPY in CA neurons in both rat and man. Furthermore, in the dorsal part of the nTS complex (dorsal strip and dorsal sub-nucleus) PNMT/NPY costoring neurons (Fuxe et al. 1986; Härfstrand et al. 1987a) are intermingled with the baroreceptor afferents (Kalia, 1981). In physiological experiments it has been shown that centrally administered adrenaline (A) (Zandberg et al., 1979; Burkowski and Finch, 1980; Brazenor and Bentley, 1981; Kubo and Misu, 1981), clonidine (CL) (Kobinger and Walland, 1967; Bolme and Fuxe, 1971; Haeusler, 1973) and NPY (Fuxe et al., 1983; Härfstrand et al., 1984) produce a lowering arterial blood pressure, heart and respiratory rate. Furthermore, these effects of NPY and A are also present in the awake unrestrained rat (Härfstrand et al., 1986c, d). Both NPY and CL may inhibit the adenylate cyclase in the nTS area (Härfstrand et al., 1987b).


Arterial Blood Pressure Mean Arterial Blood Pressure Nucleus Tractus Solitarius Antagonistic Interaction FMRF Amide 
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© The Wenner-Gren Center 1987

Authors and Affiliations

  • Anders Härfstrand
  • Kjell Fuxe
  • Luigi F. Agnati

There are no affiliations available

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