Tatsuo Gonda

Coexistence of substance P- and methionine5-enkephalin-like immunoreactivity in nerve cells of the myenteric ganglia in the cat ileum

Intramural ganglia of colchicine-injected cat ileum were examined immunohistochemically using antisera to substance P (SP), vasoactive intestinal polypeptide (VIP) and methionine5-enkephalin (ENK). SP- and ENK-like immunoreactive nerve cells were preferentially located in the myenteric ganglia, whereas VIP-like immunoreactive nerve cells were distributed in both myenteric and submucous ganglia. A small number of nerve cells in the myenteric ganglia showed immunoreactivities to both ENK and SP antisera, but not to VIP antiserum. These findings provide supportive evidence for the coexistence of SP and ENK in a small population of neurones in the cat myenteric plexus.

Distribution of nerves containing vasoactive intestinal polypeptide-like immunoreactivity in rats with congenital aganglionosis of the colon

Summary The distribution of nerves containing vasoactive intestinal polypeptide-like immunoreactivity was examined immunohistochemically in whole-mount specimens of the colons of mutant rats, which completely lacked intramural nerve cells in the colon, and of their normal littermates. In the aganglionic colon, greatly diminished numbers of vasoactive intestinal polypeptide-like immunoreactive nerve fibers were found in the circular muscle layer, lamina propria of the mucosa, and in the submucosa. In the intermuscular space of the aganglionic colon, unlike the pattern of the normal Auerbachs plexus, vasoactive intestinal polypeptidelike immunoreactive nerve fibers were arranged in an irregular, coarse network. These findings suggest the existence of extrinsic nerves containing vasoactive intestinal polypeptide in the aganglionic colon of the hereditary aganglionic rat.

Exaggerated Stress Responses of a Chromosome-1 Congenic Strain Derived from Shrsp/Izm and Wky/Izm

P136 Background: QTL mapping studies showed that the rat chromosome 1 includes a gene responsible for hypertension in SHR. To understand roles of this putative hypertension gene on the cardiovascular physiology, we studied stress responses of a congenic strain with the chromosome-1 blood pressure (BP) QTL transferred from SHRSP/Izm. Methods: The region between D1Wox29 and D1Rat112 (∼60cM) was introgressed from SHRSP/Izm to WKY/Izm by repeated backcrossing. The established congenic strain (CONG) covered a 100:1 support interval for the BP QTL found in the previous study (Am J Hypert 1999;12:1098). After telemetry probes were implanted, age-matched male CONG and WKY (5-6 month old) were used in the following experiments; 1) Restraint stress: rats were put in small tubes for 1h at room temperature and BP was monitored with radiotelemetry. 2) Cold stress: rats were kept at 4 C for 2h and BP was monitored using telemetry. Results: Without the stresses, BP measured with telemetry was not different between WKY and CONG (Table) although tail-cuff measurement gave a significant difference in BP between the two strains (141±3.5 and 154±8.3mmHg for WKY and CONG, p