Polymethacrylic acid: effects on lymphocyte output of the thoracic duct in rats.

The synthetic polyanion, polymethacrylic acid, was applied intravenously to thoracic duct cannulated rats. An increase of the lymphocyte count occurred in the lymph and in the peripheral blood. Polymethacrylic acid mobilized the lymphocytes from the reservoirs.

Exocrine pancreatic secretion: effect of subarachnoidal application of cholecystokinin octapeptide in rats.

Administration of cholecystokinin octapeptide (CCK-8) intravenously, or in the subarachnoidal surface of the olfactory lobe in rats, caused an increase in pancreatic protein and amylase secretion. It was observed that for subarachnoidal administration of CCK-8 both protein and amylase outputs were higher than that seen after i.v. injection. This result is consistent with the presence of central CCK receptors which when activated can enhance pancreatic exocrine secretion. The blockade of the effect of CCK by administration of CCK-8-specific antisera proves the specificity of the subarachnoidal CCK-8 stimulation.

Radioprotective effect of a protein free parathyroid extract on the mitotic index of rat bone marrow cells.

The protective efficacy of an orally administered bovine protein-free parathyroid extract (PF-PTE) was studied on rat bone marrow cells in vivo with the mitotic index after 850 R irradiation. A remarkable decrease was found in the mitotic activity of bone marrow cells after irradiation in the non-protected animals. However, in the animals treated with PF-PTE after irradiation, a significantly smaller decrease and a faster recovery were found in the mitotic activity of the bone marrow cells.

Radioprotective effect of a protein free parathyroid extract.

The radioprotective effect of a bovine protein-free parathyroid extract was studied in rats, being administered orally after irradiation. A significant increase in survival was found after treatment compared to conrols. It is assumed that the extract contains a new, probably as yet unknown bioactive agent responsible for the radioprotection.

Effect of protein-free parathyroid extract (PF-PTE) and gamma-L-glutamyl-taurine (glutaurine) on X-ray induced hyperglycaemia in the rat.

The protein-free parathyroid extract (PF-PTE) and gamma-L-glutamyl-taurine (glutaurine) produced mild hypoglycaemia in rats. Treatment with PF-PTE or glutaurine prevented the development of hyperglycaemia induced by X-ray whole body irradiation with 154.8 or 219.3 or 258.0 mC/kg doses. The plasma IRI values did not change following treatment. It is supposed that glutaurine acts by its antagonistic effect on glucocorticoids but its regenerating effect on the intestinal mucosa cannot be excluded either.

Incorporation of 3H-2,3-DL-valine into pancreatic proteins of adrenalectomized rats stimulated with pancreozymin-CCK and secretin.

Incorporation of labelled valine was investigated in bilaterally adrenalectomized rats stimulated with pancreozymin-CCK and secretin 14 days after operation. The growth of rats, the blood pressure, the amount of pancreatic juice and the amylase output was less in the adrenalectomized animals as compared with sham operated or adrenalectomized and corticosterone substituted controls. The amylase concentration in the pancreatic juice reveals no difference between the groups but the output of amylase remained below that of the controls. The incorporation of labelled valine was higher in the pancreatic tissue and proteins in the adrenalectomized animals than in the controls. It is assumed that the adrenalectomy causes primarily a depletion in the metabolic activity and systemic blood pressure; diminished pancreatic juice secretion and output of amylase are only secondary consequences which are not compensable by hormonal stimulation of pancreatic secretion.

Lymphocytosis induced by polymethacrylic acid. Dose-effect and toxicity.

Intravenous polymethacrylic acid (PMAA) significantly increases the number of lymphocytes in the blood of the rat. The relationship between dose-effect and lymphocytosis is linear. The lethal dose in 30 days of PMAA is 120 mg/kg b.w. and the half-lethal dose 80 mg/kg b.w. The treatment with 40 mg/kg b.w. intravenous PMAA gives no toxic histological changes either in the lymph organs, the liver or the kidneys. Thus, PMAA appears to be, at present, a most suitable agent by which to provoke experimentally, migration of the reserve lymphocytes into the blood.

Nitrate induced changes in sensoro-motor development and learning behaviour in rats.

Development of sensoro-motor functions and adult learning behaviour was studied in rats subjected to nitrate exposure. Pregnant and lactating dams and their offspring were supplied with drinking water containing nitrate, 1.12 or 2.24 mM KNO3, and compared with nitrate-free controls. Postnatal maturation of reflexes, that of sensory and somatic parameters and motor activity, furthermore, the acquisition of one-way avoidance and rewarded discriminative learning behaviour in adulthood were examined. Reflexes (righting, cliff-avoidance) and hearing startle reaction maturated earlier in nitrate treated groups. No difference was found in olfactory homing behaviour, in the time of eye opening and in body weight growth. Open-field motor activity was higher at days 5, 7, 10 after birth, but hypoactivity ensued after day 20. A marked learning deficit was observed both in punished and in rewarded learning paradigms. The results indicate a nitrate induced deviation in behavioural development, and an impairment in learning behaviour, particularly of discriminative type.

A new technique for chronic pancreatic cannulation in rats.

A new type of chronic pancreatic cannula is intended for examination of pancreatic exocrine secretion in conscious rats moving freely in their cages between the experiments. The recirculation of pancreatic juice and the free flow of bile into the duodenum is ensured. The pancreatic juice volume, protein output, amylase activity, and bicarbonate output were significantly higher in the chronically cannulated conscious rats than in the acutely anaesthetized cannulated rats. Advantages of the new cannula and the cannulation technique are described.

The distribution of 3H-gastrin and 14C-pentagastrin in the blood and lymph of rats.

3H-gastrin (0.83 mug/rat) or 14C-glycine-pentapeptide amide (100 mug/rat) were injected into the femoral vein in various groups of rats and radioactivity was measured in the arterial blood plasma and thoracic duct lymph in consecutive 5--10 min. periods for 60 minutes. Radioactivity excreted in the bile for 30 minutes was injected into the blood and lymph was followed for 120 minutes. It has been observed that labelled gastrin or pentagastrin activity reaches its peak in the plasma in the 5th minute after intravenous injection. Next, activity in the plasma decreased after the injection of labelled gastrin, but remained unchanged after the injection of labelled pentagastrin. In the lymph, radioactivity reached its peak value between 5--15 min. after the injection of the labelled hormones. This peak value was two- to threefold of plasma radioactivity measured at the same periods. After the intravenous injection of labelled pentagastrin radioactivity was excreted in the bile; injecting this radioactive bile into the jejunal lumen, radioactivity was reabsorbed mainly into the blood circulation.

Stimulation of bile and pancreatic secretion by duodenal perfusion with Na-taurocholate in the cat compared with jejunal and ileal perfusion.

In the anesthetized cat duodenal perfusion with Na-taurocholate (TC, 0.2 M, pH 6.1, 290 mosmol, 45 ml x h-1) stimulated pancreatic volume (0 to 326 +/- 236 mg x 10 min-1) and bicarbonate secretion (0 to 34.2 +/- 4.1 mumol x 10 min-1), whereas pancreatic enzyme output was sparse. Simultaneously with the pancreatic response, bile flow increased from 139 +/- 74 mg to 484 +/- 146 mg x 15 min-1 (p < 0.05). During perfusion of the upper jejunum both pancreatic and biliary responses were significantly lower than the responses to duodenal TC perfusion (p < 0.05). During TC perfusion of the terminal ileum there was no response from the pancreas, whereas the increase in bile flow accounted only for an increase in the bile-acid-dependent fraction. The concomitant stimulation of both the hydrokinetic function of the pancreas and the bile-acid-independent bile flow might be mediated by a release of secretin.