PubMed HealthSearch

Biomedical subjects

P J Noble

Publications and source records attributed to P J Noble.

6 recordsLinked to original sources

Expression of immediate early genes in rat gastric myenteric neurones: a physiological response to feeding.

1. Expression of the immediate early genes c-fos, c-jun and c-myc in rat stomach in response to feeding and gastric distension was examined by Northern blot analysis and in situ hybridization. 2. Refeeding of fasted rats induced a transient increase in c-fos mRNA abundance in gastric corpus and antrum that was sixfold within 15 min and declined within 4 h. The response was not mediated by gastrinergic or muscarinic cholinergic mechanisms; it was reduced but not abolished by hexamethonium. No changes in expression of c-jun, c-myc or the constitutively expressed protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were observed. 3. In conscious rats prepared with a gastric fistula, gastric distension with nutritive and non-nutritive solutions at a physiological pressure for 30 min induced expression of c-fos, c-jun and c-myc, but not GAPDH. 4. Messenger RNA encoding c-fos was localized by in situ hybridization to gastric myenteric neurones of animals that underwent gastric distension, but not of undistended controls. 5. The results suggest that expression of c-fos in gastric myenteric neurones is an early response to the physiological stretching of the stomach wall that accompanies feeding. With supraphysiological distension, other immediate early genes may be recruited.

Animals

Identification of the GABAA receptor alpha 3 subunit in the IMR-32 neuroblastoma cell line.

A previous report has described the presence of t-[35S]-butylbicyclophosphorothionate binding sites and GABA-gated Cl- flux in the human neuroblastoma IMR-32 cell line. We now report the further characterisation of this binding site and, even more important, the identification of the GABAA receptor alpha 3 sub-unit expressed in these cells. Cell membranes prepared from IMR-32 cells were screened by immunoblotting for reactivity with various GABAA receptor alpha subunit-specific antibodies. Of these, only anti-Cys alpha 3 454-467 antibodies recognised specifically and in a dose-dependent manner an immunoreactive band. This M(r) 58,000 immunoreactive species and the N-deglycosylated derivatives were both coincident with the respective homologues found in both calf cerebral cortex membranes and purified receptor preparations. This is the first report of the identification of a specific GABAA receptor subunit expressed in a human cell line, and it therefore provides a convenient model for the study of receptor structure and regulation.

Animals

HIV infection.

Explore the source record for details and available documents.

HIV Infections

Alloreactivity. I. Effects of age and thymic hormone treatment on cell-mediated immunity in C57B1/6NNia mice.

C57B1/6NNia mice 1, 12, and 24 months old showed loss of cellular-mediated cytotoxicity with aging. Treatment of the three age groups with different thymic hormone preparations effected their cellular mediated cytotoxicity differently. When cytotoxicity of the thymic hormone treated groups was compared to that of the physiological saline treated group, 1-month-old mice treated with serum thymic factor (FTS) at 1 microgram/mouse and 10 ng/mouse had significantly higher activity, and lower to similar activities at 12 and 24 months; TP5 (active fragment of thymopoietin) at 1 microgram and 10 ng caused significantly higher activity in 1-month-old mice, and lower to higher and significantly lower to similar activity at 12 and 24 months, respectively; TM4 (an analogue of TP5) at 1 ng showed significantly depressed activity in 1-month-old mice, and significantly enhanced activity in 12- and 24-month-old mice; thymosin at 10 micrograms and 1 microgram had slightly lower, but not significant, depression at 1 month, similar activities at 12 months and significantly depressed to higher activity at 24 months. Unimmunized control mice showed significant protection in the 12-month-old mice in comparison to 1- and 24-month-old mice. Different hormone preparations showed age- and dose-dependent effects on the ability of spleen cells to kill P815 mastocytoma. Partial restoration of cytotoxicity was observed in 24-month-old mice treated with FTS, TP5 and thymosin fraction V.

Aging