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R Getz

Publications and source records attributed to R Getz.

7 recordsLinked to original sources
PubMed1996

Autoradiographic distribution of bombesin/gastrin-releasing peptide receptors in fetal cortex transplants.

Bombesin/gastrin-releasing peptide (BB/GRP) receptors were characterized in fetal cortex transplants in the rat. Using in vitro autoradiography techniques, the density of (125I-Tyr4)BB grains was low 2 weeks after transplantation but increased 4 weeks after cortex transplantation into the adult rat fourth ventricle. Densitometry analysis of the autoradiograms indicated that (125I-Tyr4)BB bound with high affinity (Kd = 5 nM) to a single class of sites in the transplant tissue. Specific (125I-Tyr4)BB binding was inhibited with high affinity by (Tyr4)BB but not by NMB (IC50 values of 3 and 100 nM, respectively). These data suggest that GRP may act as a novel growth factor and play a regulatory role in the development of fetal cortex transplants.

Age Factors↗
PubMed1993

Forebrain ischemia in the gerbil increases lambda opiate binding in hippocampal mossy fibers.

Transient forebrain ischemia was produced in gerbils by short-term occlusion of the common carotid arteries under halothane anesthesia. Histological analysis of brains 7 days post-ischemia demonstrated characteristic destruction of CA1 pyramidal cells. lambda Opiate binding (measured with [3H]naloxone in the presence of 300 nM diprenorphine) at 7 days post-ischemia was significantly increased in the stratum lucidum of the hippocampus (the mossy fiber layer), but not in any other region measured, including other hippocampal regions, cortex, amygdala, caudate putamen, thalamus, and hypothalamus. The increase in mossy fiber lambda binding was slow to develop (no increase detected up to 48 h post-ischemia), and long-lasting (binding remained elevated at 32 days post-ischemia). While MK-801 significantly inhibited CA1 pyramidal cell destruction when administered 20 min prior to ischemia, the increase in mossy fiber lambda binding was still evident. None of seven different opioid agonists and antagonists examined had an effect on either the pyramidal cell damage or increased mossy fiber lambda binding seen 7 days after ischemia.

Afferent Pathways↗
PubMed1988

Localization of receptors for bombesin-like peptides in the rat brain.

BN-like peptides and receptors are present in discrete areas of the mammalian brain. By radioimmunoassay, endogenous BN/GRP, neuromedin B, and ranatensin-like peptides are present in the rat brain. High-to-moderate concentrations of BN/GRP are present in the rat hypothalamus and thalamus, whereas moderate-to-high densities of neuromedin B and ranatensin-like peptides are present in the olfactory bulb and hippocampus, as well as in the hypothalamus and thalamus. While the distribution of neuromedin B and ranatensin-like peptides appears similar, it is distinct from that of BN/GRP. When released from CNS neurons, these peptides may interact with receptors for BN-like peptides. BN, GRP, ranatensin, and neuromedin B inhibit specific [125I-Tyr4]BN binding with high affinity. By use of in vitro autoradiographic techniques to detect binding of [125I-Tyr4]BN to receptors for BN-like peptides, high grain densities were found in the olfactory bulb and tubercle, the nucleus accumbens, the suprachiasmatic and paraventricular nucleus of the hypothalamus, the central medial and paraventricular thalamic nuclei, the hippocampus, the dentate gyrus, and the amygdala of the rat brain. Some of these receptors may be biologically active and mediate the biological effects of BN-like peptides. For example, when BN is directly injected into the nucleus accumbens, pronounced grooming results and the effects caused by BN are reversed by spantide and [D-Phe12]BN. Thus, the putative BN receptor antagonists may serve as useful agents to investigate the biological significance of BN-like peptides in the CNS.

Animals↗
PubMed1985

Astrocytes secrete basal lamina after hemisection of rat spinal cord.

Basal lamina is reconstructed over the lesioned surface of the spinal cord. The following experiment (90 rats) studies the ultrastructure of the formation of this membrane and the immunohistochemistry of laminin production (a major secreted component of basal lamina). After hemisection of the spinal cord at T6 animals were prepared for electron microscopy or antilaminin-biotin-avidin-peroxidase incubation. Three-5 days posthemisection, antilaminin reaction product was observed in astrocytes and their processes which faced the lesion, endothelia of blood vessels or pia. Ultrastructurally (3 days), basal lamina was polymerizing as small projections on the surface of astrocytic membranes facing the lesion, endothelia or pia. By 5 days the basal lamina was a single membrane, folded multiple sheets or in swirls. At 6-10 days the antilaminin reaction and the basal lamina (except for duplications) did not differ from normal. Reactive astrocytes secrete laminin for at least 3-5 days after hemisection and form basal lamina on the lesioned surface of the spinal cord after spinal cord hemisection.

Animals↗