The actions of the peptides, neuropeptide Y and peptide YY, on the vascular and capsular smooth muscle of the isolated, blood‐perfused spleen of the dog

Abstract

In contrast to their potency on the vascular smooth muscle, NPY and PYY were significantly (P < 0.01) less potent than NA in causing contraction of the splenic capsule. The two peptides were equipotent in eliciting this contraction.

Alpha adrenergic receptors are involved in the contractile activity of neuropeptide Y in the porcine isolated ovarian artery

“…The present study revealed that NPY caused an increase in blood pressure in the isolated ovarian artery obtained from the immature and mature pigs. Similar vasocontractile effect of NPY treatment was observed in vitro in the rabbit ovarian artery (Yao et al, 1996) as well as dog, cat and pig spleen arteries (Lundberg et al, 1984; Corder et al, 1987;Pernow and Lundberg, 1988), human and sheep coronary arteries (FrancoCereceda, 1989;Kwan et al, 1990) and in vivo in vessels of rabbit (Jorgesen and Sejresen, 1990), rat (Zukowska-Grojec et al, 1986), cat (Corder et al, 1986), dog (Suzuki et al, 1988) and pig . Administration of PYX-1, a nonispecific antagonist of NPY receptors alone as well as administration of NPY into PYX-1 pre-treated vessels did not cause any significant changes (P > 0.05) in blood pressure in all the groups examined as compared to the levels determined before the peptide administration (Figure 2).…”

“…In experiments in vitro performed on dog (Chiba, 2001) and rabbit (Abel and Han, 1989) cerebral arteries, dog (Corder et al, 1987), cat (Lundberg et al, 1985) and pig (Roberts et al, 1999) spleen arteries, human (Franco-Cereceda, 1989), dog (Macho et al, 1989) and sheep (Kwan et al, 1990) coronary arteries, pig (Martling et al, 1990) and rabbit (Obara et al, 1989) pulmonary and bronchial arteries, human (Pernow and Lundberg, 1988) muscular arteries, and pig (Markiewicz et al, 1998a,b) ovarian artery it has been observed that NPY acts as a vasoconstrictor. The vasospastic effect of NPY has been also observed in experiments in vivo performed on rat (Cortes et al, 1999) and pig (Malmstrom, 2000) mesenteric arteries, rat renal interlobar arteries (Chen et al, 1997), dog spleen vessels (Yang and Chiba, 2000), rabbit ovarian ar-tery (Jorgesen and Sejresen, 1990) and cat renal and femoral arteries (Corder et al, 1986).…”

Vasoconstrictive action of neuropeptide Y in Bone: The porcine tibia perfused in vivo

“…In bone, NPY elicits its maximal response at higher concentrations than in other organs (Corder et al 1987, Ahlborg et al 1992a. This may be due to variations in vascular sensitivity to NPY in differ- -7 -6 log NPY (rnol/L) ent organs.…”

“…Thus, circulation in the mesenterium and kidneys exhibits a higher sensitivity than in skeletal bone. Differences in mode of administration, i.e., bolus injection or continuous infusion (Corder et al 1987). and differences between species may also play a role.…”

Modulation by endogenous prostanoids of the vasoconstrictor activity of endothelin‐1 in the canine isolated, perfused spleen

“…tobarbitone sodium (Sagatal,30mg kg ', i.v.) The surgical procedures involved in isolation of the spleen have been described in detail elsewhere (Corder et al, 1987). Briefly, the spleen was isolated from all connections with the stomach, pancreas and omentum and, after ligation of the splenic artery and vein, removed from the donor.…”