The distribution of immunoreactive glucagon, substance P (SP) and vasoactive intestinal polypeptide (VIP)-like structures was investigated in the rat liver, with special reference to the hepatic vasculature by means of the indirect immunofluorescence method. Immunoreactive structures of glucagon were seen in the walls of the portal vein, hepatic artery and hepatic vein, but not in the central vein. Immunoreactive glucagon was localized in the smooth muscle cells of these blood vessels. SP and VIP-like immunoreactive (SPI and VIPI) structures were seen in the neuronal elements. In the porta hepatis, thick, compact SPI and VIPI fibers, which were dissociated from their fiber bundles, reached the tunica adventitia where they were distributed. No SPI and VIPI structures were seen in the tunica media or the tunica interna. No SPI- and VIPI-containing cell bodies could be detected in the liver. These observations suggest that these peptides may have an important role in the neural regulation of hepatic hemodynamics.

Animals↗

PubMedDate not supplied

Coexistence of substance P and neurotensin-like peptides in single neurons of the rat hypothalamus.

The coexistence of substance P with neurotensin-like immunoreactivity in certain neurons of the hypothalamus were demonstrated by the double immunofluorescence method. Substance P and neurotensin-like immunoreactivity coexisted within single neurons of some hypothalamic areas such as the medial preoptic area, perifornical area, anterior hypothalamic area, lateral hypothalamic area, periventricular nucleus and posterior hypothalamic nucleus, although they did not coexist in the majority of immunoreactive cells.

Animals↗

PubMedDate not supplied

Distribution and origin of vasoactive intestinal polypeptide-like immunoreactive fibers in the central amygdaloid nucleus of the rat: an immunocytochemical analysis.

We studied the distribution of vasoactive intestinal polypeptide-like immunoreactive (VIPLI) fibers in the central amygdaloid (AC) nucleus of the rat, using indirect immunofluorescence and the origins of such fibers using a combination of retrograde tracing with immunocytochemistry. VIPLI fibers formed a dense fiber plexus in the lateral subdivision of the AC nucleus, but other subdivisions showed little immunoreactivity. Destruction of the supramammillary (SuM) region and the adjacent lateral hypothalamus, both of which contained a group of VIPLI neurons, resulted in the marked reduction of VIPLI fibers in the ipsilateral AC nucleus, indicating that many of the fibers in the AC nucleus originate from these two areas. This assumption was supported by the finding that injection of fast blue dye into the AC nucleus labeled the VIPLI neurons in the SuM region and lateral hypothalamus.

Amygdala↗

PubMedDate not supplied

Demonstration of rat preprotachykinin A mRNA in the rat trigeminal ganglion by in situ hybridization histochemistry.

The localization of gamma-preprotachykinin A mRNAs in the rat trigeminal ganglion was demonstrated by in situ hybridization histochemistry using the 32P and 35S labelled gamma-preprotachykinin A complementary DNA. In situ hybridization using 32P allowed shorter exposure times, whereas higher resolution of the hybridization signal on both film and emulsion autoradiograms was obtained using 35S. Preprotachykinin A mRNA detected by the gamma-preprotachykinin A probe was localized in about 15 per cent of the trigeminal ganglion cells, most of which were small or medium sized. Immunohistochemical studies using anti-substance P antibodies demonstrated that 15-20 per cent of total trigeminal ganglion cells were positive. These cells were small or medium sized. The result of immunohistochemistry coincided well with that of in situ hybridization histochemistry. The present study showed that the cellular localization of preprotachykinin A mRNA could be analysed by in situ hybridization histochemistry.

Animals↗