Lack of platelet factor-3 activation after incubation of platelet-rich plasma with kaolin in the rat

Summary Stypven times, measured in rat platelet-rich plasma (P. R. P.) after incubation with kaolin, did not shorten as incubation proceeded, thus reflecting the lack of development of platelet factor-3 (PF₃) availability in this test system. Repeated freezing and thawing of P. R. P. or aggregation with collagen did result in PF-3 availability. Aggregation and PF-3 availability were inhibited by the compound VK774. These findings add another aspect to the list of species differences in platelet function.This study was partly supported by a grant from I. W. O. N. L.     

Ultractructural changes in rat mammotropes following incubation with dopamine

Cultured mammotropes incubated with dopamine for one hour exhibited changes in ultrastructure indicative of actively depressed biosynthetic and secretory activity. Peripheral relocation of rough endoplasmic reticulum appeared to create a barrier to secretory granule release by exocytosis. A decrease in the numbers of secretory granules indicated a decrease in prolactin production and enhanced lysosomal activity.     

Adenyl cyclase activity of mouse liver membranes after incubation with endotoxin and epinephrine.

Adenyl cyclase activity in isolated mouse liver cell membranes was stimulated two-fold by endotoxin. Furthermore, endotoxin inhibited epinephrine induction of adenyl cyclase activity, apparently through interruption of the phospholipid moiety of the enzyme complex.     

Brain adenylate cyclase activation in the jaundiced rat.

Adenylate cyclase responses of brain cortex and neostriatum to noradrenaline and dopamine are increased in rats with jaundice in proportion to its severity. In comparing the situation with uraemia, the relevance of phenols has to be considered.     

Lack of pressor effect of dopamine in the pentobarbital-anesthetized rat

The blood pressure and heart rate responses to intravenous dopamine infusion at 2.5, 5.0 and 10.0 micrograms.min-1 X 100 g-1 were studied in conscious and pentobarbital-anesthetized Sprague-Dawley rats. In the conscious rats, dopamine caused a significant dose-related increase in the mean arterial blood pressure which was abolished in the anesthetized rats. The heart rate increased significantly only at the highest dose infused. The responses to equipressor doses of noradrenaline (40 ng.min-1 X 100 g-1) and phenylephrine (1.0 micrograms.min-1 X 100 g-1) were also suppressed in the anesthetized rats. The results suggest that pentobarbital anesthesia depresses the blood pressure response to dopamine infusion in the rat through a depression of activation of alpha-adrenoceptors.     

Lack of pressor effect of dopamine in the pentobarbital-anesthetized rat

Summary The blood pressure and heart rate responses to intravenous dopamine infusion at 2.5, 5.0 and 10.0 g·min^–1·100 g^–1 were studied in conscious and pentobarbital-anesthetized Sprague — Dawley rats. In the conscious rats, dopamine caused a significant dose-related increase in the mean arterial blood pressure which was abolished in the anesthetized rats. The heart rate increased significantly only at the highest dose infused. The responses to equipressor doses of noradrenaline (40 ng·min^–1·100 g^–1) and phenylephrine (1.0 g·min^–1·100 g^–1) were also suppressed in the anesthetized rats. The results suggest that pentobarbital anesthesia depresses the blood pressure response to dopamine infusion in the rat through a depression of activation of alpha-adrenoceptors.16 June 1986     

The fate of choline in the circulating plasma of the rat.

Labelled free choline injected into the peritoneum failed to enter the brain but preferentially entered the liver. Subsequently labelled phospholipid was found in the plasma with a concurrent increase in the brain. This labelled plasma injected by cardiac puncture caused a rapid incorporation of the choline labelled phospholipid into the brain.     

Basal plasma corticosterone level after bilateral selective lesions of the olfactory pathways in the rat

In comparison to control rats, basal plasma corticosterone level and lactacidemia significantly increased in rats submitted to a bilateral lesion of the lateral olfactory tract and/or the anterior branch of the anterior commissure. Only the lesion of the anterior branch of the anterior commissure induced hyperglycemia; that of the lateral olfactory tract exerted an opposite effect.     

Epithelial cell swelling during incubation of rat small intestine in vitro

Résumé L'augmentation du fluide du tissu de l'intestin grèle incubé in vitro s'accompagne d'un accroissement du volume des cellules épithéliales.     

Basal plasma corticosterone level after bilateral selective lesions of thee olfactory pathways in the rat

Summary In comparison to control rats, basal plasma corticosterone level and lactacidemia significantly increased in rats submitted to a bilateral lesion of the lateral olfactory tract and/or the anterior branch of the anterior commissure. Only the anterior branch of the anterior commissure induced hyperglycemia; that of the lateral olfactory tract exerted an opposite effect.     

Influence of light on the plasma gonadotropin concentrations in the newborn rat.

The physiological increase in plasma gonadotropin (LH and FSH) levels in newborn rats is indisputably influenced by light. Permanent illumination accentuates this increase, whereas darkness decreases it in 16-day-old female rats. In male rats of the same age, only permanent illumination was tested with the same results.     

Adenyl cyclase activity of mouse liver membranes after incubation with endotoxin and epinephrine

Summary Adenyl cyclase activity in isolated mouse liver cell membranes was stimulated two-fold by endotoxin. Furthermore, endotoxin inhibited epinephrine induction of adenyl cyclase activity, apparently through interruption of the phospholipid moiety of the enzyme complex.     

ADP-induced platelet aggregation in vivo after exclusion of different circulatory districts.

The effect of the ADP infusion on the basal platelet count was studied in controls and in rats submitted to the exclusion of the following circulatory districts: splenic, renal, cerebral and of a hind-limb. After these exclusions the ADP-induced thrombocytopenia was less marked than the controls.