In order to detect both pancreatic excretion of dimethadione (DMO), a weak organic acid, and the effect of pancreatic DMO on secretin-stimulated pancreatic secretion, DMO was given intravenously to dogs with pancreatic fistulae at a dose of 50, 100 and 200 mg/kg. DMO was promptly excreted into pancreatic juice; the concentration decreased exponentially as it did in plasma at the highest dose of the compound. At equilibrium of DMO between pancreatic juice and plasma, the DMO concentration in the juice depended directly on that in plasma; the juice/plasma concentration ratios for DMO exceeded 1.0, ranging from 1.7 to 2.1. Pancreatic DMO caused a small but significant decrease in the water, bicarbonate and sodium secretion at non-equilibrium, and in the bicarbonate secretion at equilibrium. A decrease in the bicarbonate secretion may result largely from the buffer action of bicarbonate on protons provided by the undissociated form of DMO. The sum of both bicarbonate and chloride concentrations in pancreatic juice decreased with the increased DMO concentration in the juice, implying that DMO may compete with the secretion of bicarbonate and/or chloride across the apical membrane of the duct cell. Pancreatic DMO can act as a non-specific inhibitor of pancreatic water and electrolyte secretions.

Animals↗

PubMedDate not supplied

Hematologic abnormalities and outcome of 16 cats with myelodysplastic syndromes.

We investigated the hematologic abnormalities and prognoses in 16 cats with myelodysplastic syndromes (MDS). Nonregenerative anemia, thrombocytopenia, and neutropenia were observed in 15, 13, and 4, respectively, of the 16 cats with MDS. Morphologic abnormalities characteristic of MDS included megaloblastoid rubricytes (9 cats), hyposegmentation of neutrophils (7 cats), nuclear abnormality of rubricytes (10 cats) and neutrophils (13 cats), and micromegakaryocytes (10 cats). Disease in these 16 cats was subclassified into refractory anemia (RA; 8 cats), RA with excess of blasts (RAEB; 5 cats), RAEB in transformation (RAEB in T; 1 cat), and chronic myelomonocytic leukemia (CMMoL; 2 cats), according to the human French-American-British (FAB) classification. In the cats in which the clinical outcome was known, 3 of 6 cats with high blast cell count MDS, including RAEB, RAEB in T, and CMMoL, developed acute myeloid leukemia, but only 1 of 8 cats with low blast cell count MDS (RA) developed acute myeloid leukemia. Based on the Dusseldorf scoring system for the prognosis of human MDS, the survival times of the cats showing high scores (> or =3 points) were significantly shorter than those of the cats with low scores (<3 points). The FAB classification and Dusseldorf scoring system were considered to be useful for predicting the prognosis of feline MDS. Furthermore, 15 of the 16 cats with MDS in this study were infected with feline leukemia virus, indicating its possible etiologic role in the pathogenesis of feline MDS.

Anemia↗

PubMedDate not supplied

Stimulation by gastro-intestinal hormones of cyclic adenosine 3': 5'-monophosphate accumulation and insulin release in isolated pancreatic islets of the rat.

In collagenase isolated rat pancreatic islets, CCK-PZ, SHG, secretin and glucagon stimulated the accumulation of cAMP, in physiological ranges. The resulting increment of cAMP showed a good correlation with insulin release stimulated by either glucagon or secretin, but not by SHG or CCK-PZ. In the same system, 14CO2 production from glucose-U-14C was significantly increased by either SHG or CCK-PZ. The results presented in this report are compatible with the hypothesis that insulin release by gastrointestinal hormones may be mediated by cAMP in the B-cell in the case of either glucagon or secretin; whereas, in the case of either SHG or CCK-PZ, it may presumably be mediated by an unknown mechanism in glucose metabolism, other than c-AMP.

Animals↗